Tuesday, August 23, 2011

GUIDE: Step by Step 17" iMac G4 TMDS to DVI Conversion - 800mhz and 1/1.25 Ghz Necks Completed


Mac Mini identifying monitor as "iMac"
This is a step-by-step detailing the process of converting a 17" iMac G4 to a useable LCD with a video cable that terminates with a DVI connector in the base.  I will focus only on the video connector and converting this LCD to be DVI compatible.  Please note that I am not starting from a complete machine.  I have several necks, empty domes/bases, and LCDs that I have obtained through various sources as individual parts.  So my tutorial will not focus on the general disassembly and reassembly, but on the wiring and powering of the LCD.


For those who have not followed my blog, please be aware that there are two versions of the wires in the 17" Mac G4 (Two different necks).  One version is for the 800mhz iMac, the other is for either the 1 or 1.25ghz iMac.  If you use the wrong one - the colors will not match up.  While the wires connect the same things, apple changed the color of some of the wires.  In addition, for the 1/1.25Ghz I have included a video tutorial to give another perspective. 


Note: Everything here is AT YOUR OWN RISK.  These mods will void your warranty and I provide absolutely no guarantee that you will have the same results as I have.  This is a financial risk, the parts that go into this are used and in some cases 10 years old.  Mistakes or even bad luck may result in no image or even permanent damage to components.  So know what you are getting into.  I can not vouch for the long term stability of this mod.  Although this mod is solder-less and simplified, obviously soldered, insulated connections are likely to be more stable.  Even though I have simplified the process, this is still an advanced mod.  Be cautious when handling live connections which (in the case of the inverter to backlight) can be several thousand volts.  So if you're still ready, lets get started:




I. PARTS LIST
These are the parts that I used or very common alternatives - MANY other variations are unquestionably possible, but I can not guarantee something I did not see work personally.  In some cases I will list where I purchased it from - this is in no way an endorsement of any particular merchant or sales site - just a statement of how I acquired it.


VIDEO TUTORIAL PART 1 (1/1.25Ghz NECK) can be seen here:
Introduction and Parts List



VIDEO TUTORIAL PART 2 (1/1.25Ghz NECK) can be seen here:
Parts List Continued




A) iMac G4 17" and components
  1. Monitor Housing - 2 pieces (front and back) contains LCD and inverter
  2. 17" Inverter
  3. Neck - while structurally the same the neck's of the 800mhz model has different colored wires than he 1ghz and 1.25ghz models.  As both pinouts are available it does not matter which you choose.
  4. Faraday Cage
  5. Dome - contains computer components (none of which are used), A white plastic overlay, a metal faraday cage (the metallic inner part of the dome), the bottom of the dome, and a circular tray for the bottom.
This is the hardest to buy.  You need a working LCD and Inverter for this mod.  As broken computers may or may not have functioning LCDs - its a tough choice. 
If possible, try not to buy and tear apart working machines - there are fewer and fewer of these available.  Ebay is littered with hundreds of broken machines and parts that can be recycled.  If the machine you buy is "dirty" - you can buy a new plastic outer housing for the dome.  If the screen or inverter doesn't work, they can also be found easily on ebay.


B) A Power Source - to power both inverter and LCD screen
Pico Power Supply

Any power source that has at least a DC: 12V and a 5V line will work, however addition of a 3.3V line actually matches up closer with the panels specs.  Despite this, I have not seen any problem with using only 12V and 5V.  As this makes everything more uniform and simpler, I am focusing on using these voltages via a standard molex connector.  Alternatives include any atx power supply with a molex. As there is limited space, you should choose a small power source like a pico power supply which is a DC-DC power source that uses an external power brick, but any atx power supply will work.  If you use an atx power supply you will have to "jump" it to get it to turn on without a motherboard.  This can be done by inserting a paper clip or wire between pins 14 and 15.  Simply put - grounding pin 14 turns on the power supply.
Rocker Switch

While this alone works you should think about putting some wire with an on/off switch between these.  Do not use a momentary switch, you need a real on/off (such as a rocker or toggle switch).

logicsupply.com has a nice selection of Pico Power Supplies, I'd probably recommend at least 120Watts.  Make sure you buy a DC-AC power brick as well.

Another option is a DC to molex power supply this gives the necessary 12V and 5V line and also connects to a regular AC plug.  This is what I am using for now.

Whatever you choose, it must simply have a working 4 pin molex plug.  My tutorial is based around using a working molex in combination with a molex splitter.  Cutting off the 2 female connectors and stripping the ends will give you 2 of each of these: 12V(Yellow), 5V(Red), Ground(Black).  Available from newegg.com.
Molex Splitter


Another possibility is using the native iMac G4 power supply.  As it has 3.3V, 5V, 12V, and Ground.  As readers have noted and I myself have tested for  the 20" this can work, but with some caveats.  I will post regarding the native PSU in the future.

C) Accessories and Cables


LVDS Cable
    1.  (Optional): Extra Small Wires and Pins. One source of extra wire is to buy LVDS cables (on ebay).  However, using wires with the proper pins will work best and it is difficult to be sure what size pins are in any given wire.  One source of iMac G4 wires is obviously an iMac G4.  Buying an extra neck as a source wires and pins may come in useful especially if you make a mistake.  These are always available on ebay and it does have to come from the same size iMac.  I used 3 small wires with pins from a 15" iMac G4 neck. (The neck does not have to be opened, I just cut off the last few inches) for the 800mhz version.

Alternatively you can use the wires in your own iMac's neck.  This will require cutting and stripping some small wires, but does work just as well.  Unless you have an extra neck or are concerned about making a mistake (once cut there is no going back), this is the method I would recommend as it saves having to purchase additional equipment.

    2.  Torx Screw driver kit or set, Philips screwdriver, Small Flat head screwdriver or mini screwdriver set.

    3.  Soldering iron and solder (not required but can be useful for making some connections more secure or for repairs).

    4.  A safety pin - for removing pins from connectors

    5.  Electrical Tape and/or heat shrink

Multimeter
    6.  A multimeter with continuity setting.  This is useful in checking the integrity of the connection especially if you are not getting an image

    7.  Alligator wires (at least 7).

A Stripped, Cut Cable
    8.  A Cable or connector for splicing.  This must be a TMDS cable such as DVI or HDMI.   Alternatives include:

          a) Cut DVI/HDMI cable: I do not recommend doing it this way.  It is easy to obtain and using a mutimeter, it is easy to find out which wires correspond to which pin.  But, the wires are difficult to work with and the solder itself can cause pixelation or "sparkles".  Simply put choice b below is much easier and likely to produce a better image.  If yo do proceed this way, after striping you will find the TMDS control wires (Clock, Data, Hot Plug, 5V) as well as 4 groups of wires that are further shielded.  These are the TMDS signal cables.  Each one of these has a positive wire, negative wire, and ground.  Also, remember when using a DVI cable the connector is MALE and this does not correlate directly to the standard diagrams and pin numbers which are based on a female connector.

DVI connectors (Female)
               b) A DVI connector (with small pins) - Although I'm sure similar ones exist.  The one I used is a right angle, female, digital only (no analog pins) dvi connector and the part number is:
MOLEX PN 74320-4004

I bought a bunch of these on ebay.  Other sources which I have personal experience with include Mouser.com which sells individual ones for under $5 and Digi-Key which sells individual one for under $4.  A search on google shopping or octopart shows Allied Electronics, Hawk Electronics, Heiland Electronics, RS Elecrtonics, Newark.com, and Onlineparts.com all stock this connector and sell it for $2 - $5 for one connector and less per unit if you buy multiples.

Octopart search
Google Shopping search

Item on:
Mouser
Digikey
Newark
OnlineComponents
Allied Electronics
RS Electronics

The advantages of this are many.  The pins can be pushed in, but if a mistake is made they can easily be removed.  No soldering of tiny wires is required and the connection quality will likely be better.  This is because the shorter the cable, the fewer the connections/solder points and the smaller the changes in resistance, the better the quality of the connection.  This also allows use of female connector (pin out is easier to follow).  It is very likely that other small pin DVI-D or DVI-I connectors will work, but I used this one and can therefore only vouch for this particular connector.  I have no special knowledge if other random connectors or part numbers will work.  Here are some data sheets on this connector if you want to compare it to another.

http://datasheet.octopart.com/74320-4004-Molex-datasheet-60256.pdf
http://datasheet.octopart.com/74320-4004-Molex-datasheet-62695.pdf
http://www.molex.com/pdm_docs/ps/PS-74320-001.pdf


I highly recommend this DVI connector it greatly simplifies the process and is much more stable.  I can not emphasize this enough.  My guide is based on this connector.

    9. At least two 1-Kohm resistors.  I used these from parts express via amazon.

  10. Wire cutters, strippers, and a scissor.
           
II. Disassembly
Courtesy of mrtotes
          - I have decided to skip a lengthy tutorial on disassembly.  Numerous tutorials exist on line for this.  Changing the hard drive requires near total disassembly.
Here is one tutorial for the hard drive:
 http://www.xlr8yourmac.com/systems/iMac_g4/imacg4_takeapart.html
And one teardown:
 http://68kmla.org/forums/viewtopic.php?f=13&t=13550

Briefly:
        - Using the torx screwdrivers open up the iMac's dome and remove the drive caddy which includes the hard drive and optical drive and set it to the side.  Physical removal of the fan, internal speaker, motherboard and power supply are not required and can either be done or left alone depending on what you plan to do with the iMac's base.

Inverter plug unhooked
Video cable unplugged
        -  Removal and isolation of 2 cables: the inverter and LCD is required.
Disconnect all cables.  I would recommend at least removing the drive caddy.  The rest is up to you.

Remove the black cover from the video cable with a flat head screwdriver and gently remove it from the motherboard.

Also remove the large plug which contains the cable labelled inverter
Using a safety pin lift up the black tabs
on the large inverter connector.  As the tabs are lifted gently pull each individual inverter pin free.

Video Tutorial Part 3: Freeing the Inverter Cables


Video Tutorial Part 4: Freeing the LCD Cables





For the iMacs LCD cable you must first remove the metal casing using a flat head screwdriver or x-acto knife.

- First pry open the top
- Then the side
- And then the metal cover should bend back and snap off


Pry open the top

Then the side
Peel Back and Snap Off

Exposed LCD Connecter
When the black is fully exposed you will again see little plastic tabs on the side.  Using a safety pin lift these tabs and push them down (its ok if they come off entirely).  You want to see the exposed metal from the pins where the tabs used to be.

When all tabs are done, VERY GENTLY pull the individual wires and pins free.

You may need to again use your safety pin to press down on the pin in the area where the tab used to be in order to help free it from the black connector.


NOTE: THE ENTIRE EASE OF THIS MOD IS DEPENDENT ON THE PRESERVATION OF THE WIRES WITH THEIR INDIVIDUAL PINS.  RIPING OFF EVEN ONE PIN FROM THE WIRE MAKES THIS MUCH MORE DIFFICULT.  USE MINIMAL FORCE AND TAKE YOUR TIME.














III. The Inverter


VIDEO TUTORIAL PART 5: HOOKING UP THE INVERTER

  - I recommend hooking up and verifying the inverter first.  This way you know right away if you need to replace your inverter.


  A)The pinouts
To the left are the pinouts for the inverters.  I had thought that  the 1/1.25ghz iMac used a neck that had an Orange Dimming wire in the inverter while the 800mhz had the off white.  However, on the neck I used here which was clearly an 800mhz neck, there was an orange dimmer wire.  While this does not matter (as both are left floating), it does mean that this is not a valid means of telling the different models apart.

I have altered these inverter pinouts to reflect the fact that they way we are using this there is no difference if the purple is hooked up or not, so I am now recommending leaving this wire floating.  I believe that the purple is likely involved in sleep with the iMac with with the way we are hooking it up it does not seem to matter.  The Green is likely a sleep-wake wire, as it will turn off when disconnected, but can not by itself turn back on.  The Red can turn the entire inverter on or off, as such (although this may not reflect its initial function), I have labeled this on/off.

* I have also differentiated between how we have the red hooked up when we want to test the backlights vs when we have our DVI source connected.

B) The molex splitter

1.  Take your molex splitter and cut off the two female connectors.

2  Strip the ends off:
      - 1 Yellow (12V)
      - 2 Red (5V)
      - 2 Black (Ground)
   2 Blacks and 1 Yellow can remain with no wire exposed

Molex Splitter To AC Power Source
(Note: I removed the extra black pin
but this is not necessary)
3. Connect the molex male end to the female molex of your power source which should be OFF

4.  Place Alligator Wires on
- Attach Yellow Alligator wire to one yellow molex wire (Note: I have two attached in the pic but you only need one)

- Attach Black Alligator wire to one black molex wire

- Attach Two Red Alligator wires to red molex wires (but on 1 wire attach sideways leaving end exposed for a second wire) as seen in picture.

- Attach one Green Alligator wire to end of the red molex wire. (Using Green simply helps telling the wires apart).
Alligator Wires to Molex (yellow is out of frame)

5. Take 2 1 Kohm resistors and twist one end onto the PURPLE and GREEN wires of the inverter cable
(Note: Purple does not appear to be necessary)
Resistors wrapped around Green and Purple pins


 6. Connect your alligator wires to the inverter pins

- Connect Yellow to Blue pin

- Connect either Red to Red

- Connect the other Red to the resistor wrapper around the Purple pin (Does Not appear to be necessary - Can leave floating)

- Connect Green to the resistor wrapped around the Green pin

- Connect Black to the Black pin

- Orange or White (depending on neck) inverter wire is not connected and left floating.

7. Turn on your power source.  The backlights should come on as seen below.  If so, turn off the power and continue on.  If not check your connections.

The backlights on







IV: The LCD Cable
- Be aware this will split into two different parts, one for the 800mhz iMac and one for the 1/1.25ghz.  If you do not know which one you have, see my two necks post.  The easiest (without disassembly of LCD) is to see if your black LCD cable contains a BROWN or ORANGE cable.  These will split into a red, green, black.  BROWN = 1/1.25ghz and ORANGE = 800mhz.


1. Grab your DVI connector and find a good DVI/TMDS pinout for reference in you get confused.  The one I have pictured below is courtesy of Tom's Hardware.   Just remember the numbers reflect a FEMALE DVI connector.  This is a digital only signal, so we will be using the areas highlighted a TMDS and also the control areas (labeled plug and play).  A TMDS data source actually contains 3 parts - POSITIVE, NEGATIVE, and GROUND.  DVI allows up to 7 of these (0,1,2,3,4, and Clock).  The iMac's LCD requires 4 (0,1,2, and Clock).  These correspond to the 4 colored wires that are in the iMac's black LCD cable.  And each one of these has 3 wires inside a red, green, and black.  This corresponds to the positive, negative, and ground signals respectively.
Courtesy of Tom's Hardware
2. Orient Yourself
FEMALE DVI CONNECTOR PIN NUMBERS

There are 3 Rows of 8 holes

The picture on the right is the front view
- The Top is recognizable as the "Analog Area" should be on the right when looking straight on.
- In addition, the connector is a parallelogram and the longer side is on top
- They are numbered left to right and the middle 2 rows are not used at all
- The Red boxes correspond to the pins for the TMDS signals (the pins in the iMac's black wire)
- The Green boxes correspond to the pins for the control (the pins in the iMac's gray wire)


Connector from top
As this is a right angle connector there are right angle pins visible on the top of the connector.  This then terminates in the male pins we will be using on the bottom.  See TOP VIEW

In the BOTTOM view below you can see that the top row pins (1-8) actually become the bottom row when looking at the pins from this angle.

The "Analog Area" will always be at the end.  So the closest pins to this area will be 8, 16, and 24 in the top, middle, and bottom rows respectively.


Bottom View of connector with"Free" iMac LCD cable.
LCD Cable with black heat shrink removed
3. Separate the Black and Gray iMac LCD wires

-  This gives you much more room to work with

-  Using a small scissor or wire clippers cut a small nick into the black heat shrink which envelopes both wires.

-  With your hands pull apart the sides of the heatshrik next to your cut.  It should pull apart easily.

-  Underneath is a piece of gray cloth tape, unravel this until the wires come apart



THIS GUIDE NOW DIVIDES


THE RED BELOW WILL BE FOR THE 17" iMAC G4 - 800Mhz VERSION / NECK


THE BLUE FURTHER DOWN WILL BE FOR THE iMAC G4 1 or 1.25 Ghz VERSION / NECK (VIDEO TUTORIAL)


The 800mhz Neck:


4.  The Pinout


Review this pinout for reference.  This tells you which color wire and female pin (left column) will be pushed into which male pin on the DVI connector (right column).  In the middle is a description of the wires function.


800 mhz 17" iMac G4 pinout
5.  The TMDS Signal - The Black LCD Cable


A) THE RED WIRE
- Locate the RED wire from the black cable and identify the 3 wires that come from this cable.  The Green, Red, and Black.


Red Wire - Connecting Data Cable #2 (Pins 1, 2, and 3)
- This is the Data #2 Cable
-  Of note is that the small green cables will always be negative and the small red cables positive.  The Black is the shield or ground.
- Locate Pins: 1, 2, and 3 on the connector
- With the actual DVI part face down, find the pin furthest away from the "Analog Area" and on the row closest/top row.  This is PIN #1


i) Take your Red to Green wire
- Using your fingers position the female pin with the "seam" facing either up or down (towards the Front to back of the connector).
- DO NOT PUSH IT IN SIDEWAYS.
- Using very gentle force slide the Green wire on to PIN #1.  You can press until to reach the plastic of the connector.
-  Do not push against significant resistance.  The pin should fit easily and securely.
- Once in place it should hold fairly firmly.


ii) Take your Red to Red wire and push it into position #2 next to the green wire.


iii) Take your Red to Black/Shield and push it into position #3 next to the red wire.




B) The Orange Wire
- The is Data Cable #1
- Locate Pins 9, 10, and 11
- These are the middle row pins in the same column as the Red wire you just placed.


i) In the middle row, right in front of the Red to Green pin, furthest from the analog area, place your Orange to Green Pin - Position #9


ii) Next to this in Position #10 (in front of the Red to Red), place your Orange to Red pin.


iii) Finally in Position #11 (in front of the Red Shield/Ground), push the Orange Shield/Ground into place.


Orange Cables Pins Directly in Front of Red Cables Pins


RED, ORANGE, and BLUE Connected
C) The Blue Wire


- This is Data Cable #0
- Locate Pins 17, 18, and 19
- These are the top row pins (bottom view) just above the orange pins you just placed.



i) In the top row (the blue square), right in front of the Orange to Green pin, furthest from the analog area, place your Blue to Green Pin - Position #17

ii) Next to this in Position #18 (in front of the Orange to Red), place your Blue to Red pin.

iii) Finally in Position #19 (in front of the Orange Shield/Ground), push the Blue Shield/Ground into place.





D) The Green Wire

- This is the Data Cable - Clock
The Green Wire (Notice how its the mirror image)
Small Green Always on the outside
Shield/Black in the Center
- Locate the Pins #22, 23, and 24
- These pins are the last 3 in the row, closest to the Analog Area.  They are in the same row as the pins from the BLUE WIRE you just placed.  The row closest to the DVI interface.
-  NOTE THAT THE ORDER OF PINS IS DIFFERENT FOR THIS WIRE
          PREVIOUSLY ALL PINS WENT GREEN, RED, SHIELD FOR THE GREEN IT IS REVERSED.  IT GOES SHIELD, RED, GREEN
          THINK OF IT AS THIS, GREEN IS ALWAYS ON THE OUTSIDE, SHIELD ON THE INSIDE.
          SO FOR THIS WIRE WE WILL PLACE THEM GOING RIGHT TO LEFT


i) In the top row, same row as the Blue Wire, closest to the analog area (the last pin in the row), place your Green to Green Pin - Position #24

ii) Next to this in Position (going right to left) #23 (same row as Blue), place your Green to Red pin.

iii) Finally in Position #22 (same row as Blue), push the Green Shield/Ground into place.

Completed Top View



Completed Front View
Green Wire's Pins in Foreground on Left
Blue Wire's Pins in Foreground on Right











6.  THE GRAY LCD CABLE
- Of the Nine Colored Wires inside the Gray LCD Cable, only 3 of them actually connect to the DVI connector (Red, White and Black).  The other 6 connect to either 5V or Ground


THE POWER SOURCE:
A) The 5V Cables
-  Grab your Gray LCD Cable
-  Separate Out the Blue, Orange, and Yellow
-  Take a RED alligator Wire and place these 3 pins securely within its teeth
BLUE, ORANGE, and YELLOW to 5V
B) The Grounds
- Do the exact same thing for the 3 Grounds:
- Separate out the Gray, Purple, and Green Wires from the Gray LCD Cable
- Take a Black alligator Wire and place these 3 pins securely within its teeth
On Left: BLACK ALLIGATOR (Purple, Grey, Green)
On Right: RED ALLIGATOR (Yellow, Blue, Orange)

C) Connect to Power Source
- Looking Back at your power source, at one 5V RED MOLEX wire add the RED Alligator from the Gray LCD cable.

- For the Ground connect it to the unused Black Molex Wire.  The other black cable should be attached to an alligator wire going to the Black Pin/Wire on the Inverter Cable.



7. THE TMDS CONTROL WIRES (VEDID, GROUND, and HOT PLUG)


*IN THIS VERSION I USED WIRES WITH PINS FROM AN EXTRA iMAC NECK.  IF YOU DON'T HAVE OR WISH TO USE AN EXTRA NECK, YOU CAN CUT SOME WIRES WITH PINS FROM THIS iMAC NECK ITSELF.  ALTHOUGH SOMEWHAT RISKIER, THIS WORKS JUST AS WELL AS SAVES HAVING TO BUY AN ADDITIONAL NECK.  I COVER HOW TO DO THIS BELOW, BUT FEEL FREE TO SEE THIS PART OF THE GUIDE IN THE BLUE SECTION (1/1.25GHZ NECK), IN WHICH I INCORPORATE THIS METHOD.


- These 3 Wires will Plug into Pins 14, 15, and 16, respectively.  This is the Middle Row of Pins directly behind the 3 pins from the Green Wire on the Black LCD Cable.
- Only 3 wires from the iMacs LCD cable remain unused.
- However there are a Total of 5 TMDS Control Pins, only 3 come from the iMac's wires, for the 3 listed above we will need extra small gauge wire, similar to the wires on the iMac's Gray LCD cable.
- For this part really some small gauge (about 24 - 28) wires.  3 wires should include pins that can plug into the DVI connector.  Since the only pins I can verify that do this are the iMac G4's neck pins, an extra neck is needed for this method.
- Note: This is probably the trickiest part.


A) Prepare your extra wires
- Method #1: Using wires from only one neck:
Peel back the Gray LCD cable's Plastic and Shielding about 16cm.  Isolate the Ground Wires: PURPLE, GREEN, and GRAY. (You can use the 5V wires as well, but I would feel safer cutting the grounds).  Cut these three wires at about 3 - 4 inches.  Make sure you leave enough wire remaining so that it can be easily stripped.
Insulation seen after shielding removed.

*Note these pics reflect an extra damaged iMac cable I had.  I used wires from an extra iMac G4 neck for this mod, but again, I did use this method for the 17" 1/1.25 Ghz Guide.

Shielding and Insulation Peeled Back
Take the now cut ends of the PURPLE, GREEN, and GRAY wires in the Gray LCD cable and strip the last few centimeters of each of these wires so that each now has exposed wire at the end.  Twist these 3 wires together.  You can now hook this up to an alligator wire or a different wire and hook it back up to the Molex's Black/ground wire.

We now have 3 wires, although not needed a 4th is helpful for connecting, any small gauze wire can be used from any source.  You use an extra cable such as the iMac's speaker or fan wires or an LVDS cable with or without a male pin on the end (a male pins allows you to plug not the female pin of the iMac's cable, but you can just as easily strip the wire and wrap it around this pin).

- Method #2: Using wires from an extra neck:
Cables from the LCD connector of a 15" iMac G4
I used 1 cable from an LVDS cable (my optional 4th wire) and 3 with pins from the neck of an iMac G4 15".  The same method as above is applied, the shielding and insulation are peeled back from the LCD wire on the dome side of the extra neck.  3 - 4" of 3 wires are cut and the non-pin ends are stripped.


The wires from 15" iMac neck with pins on
B) The 1st Extra Wire - TMDS CONTROL GROUND


i) Take one wire with a pin on it - I USED A GREEN COLORED WIRE - but it does not matter what color you use, just remember what it is.  Strip the non-pin end of the wire.


- I am going to recommend a small wire stripper, but to be honest, I usually use (against all dental recommendations) the bite and pull method.


One wire with pin on one end, stripped on other
ii) Wrap the stripped end around the your neck's LCD Ground wires: the Green, Grey, and Purple Grounds from the Gray LCD cable that is currently connected to a Black Alligator Wire which connects to the Black Molex Wire (The Ground).  You can also use other grounds, it does not matter, but this is likely the easiest.  So now 4 wires total are in the teeth of this alligator wire.  [If you used Method #1 and cut your own neck wires you will now note that you are in essence wrapping the cut wire back from once it was cut, however, this wire will now used to ground the DVI itself].
Alligator wire with "Extra" Green Wire wrapped around
iii) Place the Pin from this Wire into Position #15 on your DVI Connector
- This is in the Middle Row, the last pin from the end (by the Analog Area)
- This pin gets placed directly behind the RED pin from the GREEN wire of the BLACK LCD cable (the last colored wire we placed).


Ground Wire to DVI Connector #15
C) The Second and Third Extra Wires - TMDS Control Voltage (VEDID) and Hot Plug


Some quick background: 
- An oversimplification, but, the DVI source (the computer) actually has a pin that sends a 3.3V signal to the LCD that tells it to turn on.  This is how the image turns off when the computer tells the monitor to sleep.  In addition, the LCD itself sends a low voltage in THE OTHER DIRECTION, back to the DVI source (the computer).  This lets the computer know that there is something connected to this port.


- The voltage sent from computer to LCD (the LCD's on/off) is called the VEDID and this is Pin #14 on the DVI and connects to the Red (looks somewhat "Hot Pink") wire in the Gray LCD cable where its transmitted to the LCD itself.


- The voltage sent from the LCD to the computer is called the "HOT PLUG DETECT".  This signal is supposed to come from the LCD and plug into Pin #16 on the DVI Connector.  However, this monitor was  designed to always be connected.  So, the iMac's LCD does not have a wire that corresponds to the Hot Plug Detect.  To "fool" the computer we can give its own signal right back to itself.  However, we need to add resistance by adding a 1-Kohm resistor.
3 Extra Wires and Resistor


i) Get Prepared


     a) Take Your "2nd Extra Wire" with Female Pin,  cut and strip the end, but strip off a large segment of the end without the pin.  I used another wire from my extra 15" iMac neck, with a female pin, Method #2.  My wire is recognizable as the Red with Black Stripe.  This wire will be the VEDID and will connect to Pin #14 on the DVI Connector


    b) Take Your "3rd Extra Wire" with Female Pin, repeat as above.  Although you don't need to strip off quite as much.  This wire is recognizable as an Orange with Blue Stripe.  This wire will be the HOT PLUG DETECT and will connect to Pin #16 on the DVI Connector.


    c) (Optional) Although not necessary, one additional wire helps, it can have either a male pin or no pin at all.  I took this wire from an extra LVDS cable.  But having no pin and simply being stripped on both ends will work fine.  This wire can be short (2").  This is a plain RED wire with a male pin on the end.


    d) A 1 Kohm resistor


ii) Create Your HOT PLUG and VEDID
Extra wire wrapped around 1st part of strip
- So you should have 3 wires


    1) VEDID - Wire with female pin at one end and a long section of stripped/exposed wire at the other end - MINE IS RED WITH BLACK STRIPE


    2) HOT PLUG - Wire with female pin at one end and a short section of stripped/exposed wire at the other end - MINE IS ORANGE WITH BLUE STRIPE


    3) EXTRA WIRE (Optional) - Short Wire with either male pin or short strip/exposed wire at one end and short strip/exposed wire at the other end. MINE IS A PLAIN RED WIRE


-Wrap the non-pin/stripped half of the Red with Black Stripe Wire / The VEDID around either the hot pink/red wire's pin from the iMac's Gray LCD cable (if you do not want to use the optional extra wire) or the non-pin/stripped end of your optional extra wire - Plain Red, BUT LEAVE SEVERAL centimeters of stripped wire from the VEDID sticking out as seen in the picture.


- Wrap the 2nd part of the VEDID's strip (the part left sticking out above) around the 1 Kohm Resistor


- Wrap the Stripped end of the Hot Plug Cable (ORANGE WITH BLUE STRIPE) around the other end of the resistor.


Completed VEDID and HOT PLUG Cable
Completed Cable View #2
Again, what you see above is simply a split.  The voltage goes from the computer through the DVI connector to the VEDID (Red with Black Stripe Wire via Pin#14).  It then splits into two.  One signal sends the original 3.3V via the "Plain Red Wire" to the Red/Hot Pink wire (or directly to the Hot Pink if you did not use the extra wire) of the Gray LCD cable, which carries this to the LCD to turn it on.  The second split sends the 3.3V from the VEDID to the 1Kohm Resistor and connects back to the DVI connector via the HOT PLUG (Orange with Blue Stripe via Pin #16).  Thus, going through the DVI connector to "fool" the source.




- If you used the extra wire, wrap the Resistor and exposed splice with electrical tape.  If you did not, you will need to leave the splice connection exposed to add another splice with the Red inverter wire as noted if part D below.

Resistor wrapped in Electrical Tape


VEDID (#14) and HOT PLUG (#16) surround
GROUND (#15)
iii) Plug the VEDID to Pin #14
- This pin is in the middle row, next to the the Ground wire that was just placed.
-  It is 3 pins from the "Analog Area" at the end
- When looking at the connector from the front (DVI interface facing you), this pin is directly behind the the Black/Shield from the Green Wire of the the Black LCD Cable.


iv) Plug the HOT PLUG DETECT to Pin #16

- This pin is in the middle row, on the other side of the Ground wire that was just placed.
-  It is the last pin of the row and is next to the "Analog Area" at the end
- When looking at the connector from the front (DVI interface facing you), this pin is directly behind the the Green from the Green Wire of the the Black LCD Cable.


v) Connect to iMac's LCD Cable
- If you did not use an extra wire this step is already done, as the first part of the VEDID is already connected to the Hot Pink/Red wire of the Gray LCD cable.  However, as you can see the extra wire gives us some extra room and flexibility and also gives us an extra connection.  This will come in useful later, because we will splice/split this 3.3V source again to use with the inverter at the end of this mod.
- You should have 2 of the 3 ends plugged into the DVI.  This leaves the one remaining short "extra cable".  I've been using the plain Red wire with a male pin.


- Take this end (if you used a cable with a male pin) and plug this male pin into the female pin on the Red (somewhat Hot Pink appearing) wire from the iMac G4's Gray LCD cable.  If there is no male pin simply strip this end and wrap it around this pin.


- There should only be 3 wires left unhooked on the Gray cable: White, Black, and Red(Hot Pink).  So, it should be easy to identify.


VEDID (Pin#14) to iMac's Gray LCD Cable - Red Wire




D) Adding Inverter Control
"The Connection" where we connect our Red Inverter Wire

- As configured the backlights will stay on during sleep as there is no signal to turn them off.  In addition, the may not come on at all when you turn on the computer.  One way to get the backlights to turn on and off with the display is to connect them to the Voltage from the Computer/DVI: The VEDID.  In effect we are taking the VEDID power source from the DVI and splitting it again (3 splits - 1 for the hot plug, 1 for the hot pink/red wire to turn on the LCD, and now 1 for the red inverter wire to turn on the backlights).  But, with the extra cable we actually split it, then split one side again.

- Take the Alligator Wire that connects to the RED INVERTER WIRE.  And Unhook the other end that is currently connected to the Red Molex 5V line.

- Take this end and clamp its teeth around the Connection (seen in picture above) between the iMac Gray Cable's Red/Hot Pink Wire and the spliced VEDID "Extra Wire".  

- If you did not use the optional wire you must add the alligator wire to the VEDID splice itself, and make it a true three way split.  This must be on the pin#14 side before the resistor.






E) TMDS Control - Clock and Data (White and Black)


Clock and Data (White and Black) to DVI #6 and 7
- 2 wires from the iMac's Gray LCD cable should still be unhooked at this point


i) Connect "White - CLOCK" to DVI Connector Pin #6
- This is in the same Row as the Black LCD Cable's RED wires but the third pin from the end / "Analog Area"
- This pin is right behind (when facing the DVI interface) the VEDID placed in the previous step.


ii) Connect "Black - DATA" to DVI Connector Pin #7

- This is in the same Row as the Black LCD Cable's RED wires but the second pin from the end / "Analog Area"
- This pin is right behind (when facing the DVI interface) the GROUND placed in the previous step.


*Please Note that these pins are reversed in the 1/1.25Ghz Neck, so do not get confused when looking at the video or the 1/1.25 guide below.

F) Connect a DVI Cable to your DVI interface - Connect the other end of the DVI cable to a source/Computer and Turn on your Power Source.  Then power on your computer or DVI source.
- You should see the image.
- Complete this mod in whatever way you see fit.  For all-in-one recommendations see my 20" Guide.

Completed TMDS to DVI.

The 1 or 1.25Ghz Neck

4.  The Pinout

Review this pinout for reference.  This tells you which color wire and female pin (left column) will be pushed into which male pin on the DVI connector (right column).  In the middle is a description of the wires function.


Important Note: This color scheme represents every 1/1.25Ghz neck I have come across except one.   During my tutorial there was a variation in the neck I used.  Because this neck was a refurbished product, I doubt too many others will have this variation, but please be aware of it.  The Black LCD cables Red wires are replaced by gray/off white white wires.  So there is a Brown, Blue, Green, and Gray (NOT RED).  SO TMDS pin numbers 12,13, and 14 are a gray wire, not red in my tutorial, but they should be RED for most everyone.  In addition, the smaller red wires that come from the Brown, Blue, Green, and Red/Gray Wires are also Gray.  So a shield, green, and Gray wire are seen.  SO TMDS pin #3 is Brown to Gray, #6 Blue to Gray, #9 Green to Gray, and #12 Gray to Gray.  Simply RED = GRAY for the Black LCD cable.  I will keep noting this during the tutorial.

As to not just repeat the above with slight variation, I have composed a video tutorial.  The first parts including the parts list and inverter can be found in the sections above, I start here with the 

5.  The TMDS Signal - The Black LCD Cable

VIDEO TUTORIAL PART 6: The Black LCD Cable






A) THE BROWN WIRE


THE BROWN WIRE to DVI
- Locate the BROWN wire from the black cable and identify the 3 wires that come from this cable.  The Green, Red (in my case Gray), and Black/Shield.
- This is the Data #2 Cable
-  Of note is that the small green cables will always be negative and the small red (or gray) cables positive.  The Black is the shield or ground.
- Locate Pins: 1, 2, and 3 on the connector
- With the actual DVI part face down, find the pin furthest away from the "Analog Area" and on the row closest/top row.  This is PIN #1

  i) Take your BROWN to Green wire
        - Using your fingers position the female pin with the "seam" facing either up or down (towards the Front to back of the connector).
        - TRY NOT PUSH IT IN SIDEWAYS.
        - Using very gentle force slide the Green wire on to PIN #1.  You can press until to reach the plastic of the connector.
        -  Do not push against significant resistance.  The pin should fit easily and securely.
        -  Once in place it should hold fairly firmly.

  ii) Take your BROWN to Red (Gray on mine) wire and push it into position #2 next to the green wire.

  iii) Take your BROWN to Black/Shield and push it into position #3 next to the red (Gray on mine) wire.

B) The BLUE Wire



THE BLUE WIRE to DVI

- The is Data Cable #1
- Locate Pins 9, 10, and 11
- These are the middle row pins in the same column as the BROWN wire you just placed.

   i) In the middle row, right in front of the BROWN to Green pin, furthest from the analog area, place your BLUE to Green Pin - Position #9

   ii) Next to this in Position #10 (in front of the BROWN to Red(Gray on Mine)), place your BLUE to Red (Gray on mine) pin.

   iii) Finally in Position #11 (in front of the BROWN Shield/Ground), push the BLUE Shield/Ground into place.


C) The GREEN Wire


THE GREEN WIRE to DVI
- This is Data Cable #0
- Locate Pins 17, 18, and 19
- These are the top row pins (bottom view) just above the BLUE wire pins you just placed.

i) In the top row, right in front of the BLUE to Green pin, furthest from the analog area, place your GREEN to Green Pin - Position #17

ii) Next to this in Position #18 (in front of the BLUE to Red (Gray on Mine)), place your GREEN to Red (Gray on Mine) pin.

iii) Finally in Position #19 (in front of the BLUE Shield/Ground), push the GREEN Shield/Ground into place.

D) The RED (GRAY on mine) Wire


***Again Please Note That My Refurbished Neck Used A Gray/Off-White Color Wire instead of a Red Color (Use Your imagination and Pretend its Red in Color for your mod).  

- This is the Data Cable - Clock
- Locate the Pins #22, 23, and 24
- These pins are the last 3 in the row, closest to the Analog Area.  They are in the same row as the pins from the GREEN WIRE you just placed.  The row closest to the DVI interface.

-  NOTE THAT THE ORDER OF THE SMALL PINS IS DIFFERENT FOR THIS WIRE
          PREVIOUSLY ALL PINS WENT GREEN, RED, SHIELD FOR THIS WIRE IT IS REVERSED.  IT GOES SHIELD, RED, GREEN
          THINK OF IT AS THIS, THE SMALL GREEN IS ALWAYS ON THE OUTSIDE, SHIELD ON THE INSIDE.
          SO FOR THIS WIRE WE WILL PLACE THEM GOING RIGHT TO LEFT

i) In the top row, same row as the GREEN Wire, closest to the analog area (the last pin in the row), place your RED (GRAY on mine) to Green Pin - Position #24

ii) Next to this in Position (going right to left) #23, place your RED to Red pin (GRAY to Gray on mine).

iii) Finally in Position #22 (same row as GREEN), push the RED (Gray on Mine) Shield/Ground into place

The RED/GRAY WIRE to DVI (Top Column on Right of DVI)





6.  THE GRAY LCD CABLE


Video Tutorial Part 7: The Gray LCD Cable




Video Tutorial Part 8" The Gray LCD Cable Continued




- Of the Nine Colored Wires inside the Gray LCD Cable, only 3 of them actually connect to the DVI connector (Red, White and Black).  The other 6 connect to either 5V or Ground
Overview
A) The 5V Cables
-  Grab your Gray LCD Cable
-  Separate Out the Purple, Orange, and Yellow
-  Take a RED alligator Wire and place these 3 pins securely within its teeth
-  Connect the other end of the Alligator Wire to the RED 5V Molex Power Wire


The 5V LCD Wires Connect to 5V Molex


B) THE TMDS CONTROL WIRES (VEDID, GROUND, and HOT PLUG)

*IN THIS VERSION I USED WIRES WITH AND WITHOUT PINS FROM THIS iMAC NECK ITSELF EXCLUSIVELY.  ALTHOUGH SOMEWHAT RISKIER, THIS WORKS JUST AS WELL AS SAVES HAVING TO BUY AN ADDITIONAL NECK.  I COVER HOW TO USE WIRES FROM AN EXTRA NECK IN THE RED SECTION (800Mhz NECK) ABOVE.

- These 3 Wires will Plug into Pins 14, 15, and 16, respectively.  This is the Middle Row of Pins directly behind the 3 pins from the RED Wire (GRAY on Mine) from the Black LCD Cable.
- There are a Total of 5 TMDS Control Pins, only 3 come from the iMac's wires, for the 3 listed above we will need extra small gauge wire, similar to the wires on the iMac's Gray LCD cable.
- For this part we need 3 wires which should include pins that can plug into the DVI connector.  Since the only pins I can verify that do this are the iMac G4's neck pins, we will cut off wires with pins from the iMac's Gray LCD Cable that do not need this pins.

1) Prepare your extra wires
- Using wires from only one neck:
Shielding removed with insulation exposed
Peel back the Gray LCD cable's Plastic and Shielding about 4".  Isolate the Ground Wires: BLUE, GREEN, and GRAY. (You can use the 5V wires as well, but I feel safer cutting the grounds).  Cut these three wires at about 3 - 4 inches.  Make sure you leave enough wire remaining so that it can be easily stripped.

Ground wires cut and both sides of cut stripped
Take the now cut ends of the BLUE, GREEN, and GRAY wires in the Gray LCD cable and strip the last few centimeters of each of these wires so that each now has exposed wire at the end.  Twist these 3 wires together.  You will eventually hook this up to an alligator wire or a different wire and hook it back up to the Molex's Black/ground wire.

We now have 3 "extra" wires with female pins, although not needed, a 4th is helpful for connecting, any small gauge wire can be used from any source.  You use an extra cable such as the iMac's speaker or fan wires which is what I used (extra black speaker wire).

Speaker wire from iMac G4 connector
Gray Wire Twisted onto Grounds
2) The 1st Extra Wire - TMDS CONTROL GROUND
i) Take one cut wire with a pin on it - I USED THE GRAY WIRE - but it does not matter what color you use, just remember what it is.  Strip the non-pin end of the wire.

- I am going to recommend a small wire stripper, but to be honest, I usually use (against all dental recommendations) the bite and pull method. 
- Take the 3 remaining ends of the Grounds (Blue, Gray, and Green) strip them and twist them together as noted above.  Take the cut Gray wire, strip the non-pin end and twist it back onto the ground wires from where it was cut.  However, do so with the wire oriented in the other direction so the connection forms a V as seen in the picture.  This V will eventually connect to a Black Alligator Wire and then connect to the Black Molex Ground.  You can either hook this up now or later.


3) The Second and Third Extra Wires - TMDS Control Voltage (VEDID and Hot Plug)
Some quick background: 
- An oversimplification, but, the DVI source (the computer) actually has a pin that sends a 3.3V signal to the LCD that tells it to turn on.  This is how the image turns off when the computer tells the monitor to sleep.  In addition, the LCD itself sends a low voltage in THE OTHER DIRECTION, back to the DVI source (the computer).  This lets the computer know that there is something connected to this port.

- The voltage sent from computer to LCD (the LCD's on/off) is called the VEDID and this is Pin #14 on the DVI and connects to the Red (looks somewhat "Hot Pink") wire in the Gray LCD cable where its transmitted to the LCD itself.

- The voltage sent from the LCD to the computer is called the "HOT PLUG DETECT".  This signal is supposed to come from the LCD and plug into Pin #16 on the DVI Connector.  However, this monitor was  designed to always be connected.  So, the iMac's LCD does not have a wire that corresponds to the Hot Plug Detect.  To "fool" the computer we can give its own signal right back to itself.  However, we need to add resistance by adding a 1-Kohm resistor. 

 i) Get Prepared

    a) Take Your "2nd Extra Wire" with Female Pin,  cut and strip the end, without the pin.  I used the GREEN wire.  This wire will be the VEDID and will connect to Pin #14 on the DVI Connector

    b) Take Your "3rd Extra Wire" with Female Pin, repeat as above.  I used the remaining BLUE wire.  This wire will be the HOT PLUG DETECT and will connect to Pin #16 on the DVI Connector.

Black "Optional" Wire to Resistor
    c) (Optional) Although not necessary, one additional wire helps.  I harvested this from the black wire of the iMac G4's speaker cable.  This is a BLACK wire, which you should strip on both ends.

    d) A 1 Kohm resistor.  Take one stripped end of the "optional" BLACK wire and wrap it around the 1 Kohm resistor.

    e) The Hot Pink/Red wire with female pin which remains connected via the iMac G4's Gray LCD cable. 


The wires: Hot Pink/Red (Top), Hot Plug - Blue (Left),
VEDID - Green (Middle), and Black with resistor (Right)
 ii) Create Your HOT PLUG and VEDID
Schematic

-Wrap the non-pin/stripped half of the GREEN Wire / The VEDID around the hot pink/red wire's pin from the iMac's Gray LCD cable.

Hot Pink to Green 
- Wrap the non resistor end of our optional BLACK wire around the Hot Pink - Green Wire connection just made above.  If you did not want to use an optional wire, instead use the 1 Kohm Resistor itself to wrap around.
Add Black to Resistor Wire to complete the split

- Wrap the Stripped (non-pin) end of the Hot Plug Cable (BLUE WIRE) around the other end of the resistor.
Attach Blue to other and of Resistor
- Completed VEDID and HOT PLUG splice
Completed

C) The GROUNDS
- Grab the remaining split and twisted ends of the cut ground wires (Blue, Green, and Gray) + the other part of the cut Gray which have been twisted into a "V"
- Take a Black Alligator Wire and Clip it onto the bottom point of the V, so that all (now 4) wires are contacted.
- Then connect the other end of the Black Alligator onto the Black Molex/Ground Wire.
Grounds (3+1) to Black Molex
D) Connecting our 3 Pins to the DVI

Again, what you see above is simply a split.  The voltage goes from the computer through the DVI connector to the VEDID (GREEN via Pin#14).  It then splits into two.  One signal sends the original 3.3V via the Hot Pink of the Gray LCD cable to the LCD to turn it on.  The second split sends the 3.3V from the VEDID to the 1Kohm Resistor and connects back to the DVI connector via the HOT PLUG (BLUE via Pin #16).  Thus, going through the DVI connector to "fool" the source.



i) Plug the VEDID (The GREEN Wire) to DVI Pin #14
- This pin is in the middle row, the same as the triplet wires from the Black LCD Cable's BLUE wire.
-  It is 3 pins from the "Analog Area" at the end
The Green Wire's Pin of our splice to DVI Pin #14
ii) Plug the GROUND (The GRAY Wire) to DVI Pin #15
- This is again in the Middle Row, the next to last pin from the end (by the Analog Area)
- This pin gets placed right next to the VEDID we just placed, one closer to the Analog Area
The Gray Wire's Pin of our splice to DVI Pin #15
iii) Plug the HOT PLUG DETECT (The BLUE Wire) to DVI Pin #16
- This pin is in the middle row, next to the Ground wire that was just placed.
-  It is the last pin of the row and is next to the "Analog Area" at the end
The Blue Wire's Pin of our splice to Pin #16

E) TMDS Control - Clock and Data (Black and White)
The BLACK - CLOCK and WHITE - DATA
to DVI Pins #6 and 7



- 2 wires from the iMac's Gray LCD cable should still be unhooked at this point

i) Connect the BLACK wire's pin - "CLOCK" to DVI Connector Pin #6
- This is in the same Row as the Black LCD Cable's BROWN wires but the third pin from the end / "Analog Area"
- This pin is right behind the VEDID (Our GREEN spliced wire) placed in the previous step.

ii) Connect the WHITE wire's pin "DATA" to DVI Connector Pin #7
- This is in the same Row as the Black LCD Cable's RED wires but the second pin from the end / "Analog Area"
- This pin is right behind GROUND (Our GRAY spliced wire) placed in the previous step.
- Pin 8 (Behind the BLUE HOT PLUG DETECT) is left unconnected.

*Please Note that these pins are reversed in the 800mhz Neck, so do not get confused when looking at the 800mhz guide above.



F) Adding INVERTER CONTROL

Video Tutorial Part 9: Inverter Control and Demonstration



- As configured the backlights will stay on during sleep as there is no signal to turn them off.  In addition, the may not come on at all when you turn on the computer.  One way to get the backlights to turn on and off with the display is to connect them to the Voltage from the Computer/DVI: The VEDID.  In effect we are taking the VEDID power source from the DVI and splitting it again (3 splits - 1 for the hot plug, 1 for the hot pink/red wire to turn on the LCD, and now 1 for the red inverter wire to turn on the backlights).  But, with the extra cable we actually split it, then split one side again.

i) Take the Alligator Wire that connects to the RED INVERTER WIRE.  And Unhook the other end that is currently connected to the Red Molex 5V line.

- Take this end and clamp its teeth around the one of two places:

Choice 1:
On the split from the spliced VEDID (GREEN) to the iMac Gray Cable's Red/Hot Pink Wire and the "Optional" Black Wire.  If you did not use the optional wire, the resistor itself will be connected here.  Thus creating a 3 way split from the VEDID.

#1: From RED inverter to the VEDID Split
Choice #2:
By using the optional Black Wire you get an additional "splice point".  You can connect the Red Alligator Wire to the interface between the Black Wire and the Resistor.  This must be on the Black wire's side of the resistor (BEFORE THE RESISTOR).  The other side where the BLUE Wire connects then goes to DVI Pin #16 CAN NOT BE USED.  This is the same effect as Choice 1, but instead of a three way split, there is now a split and then 1 side is split again.

#2: From RED inverter to the "Optional" Black Wire
and Resistor Interface
F) Connect a DVI Cable to your DVI interface - Connect the other end of the DVI cable to a source/Computer and Turn on your Power Source.  Then power on your computer or DVI source.
- You should see the image.
- Complete this mod in whatever way you see fit.  For all-in-one recommendations see my 20" Guide.


Mac Mini's image to iMac G4's 17" LCD via the neck
I have put quite a bit of time and energy into this guide.  Constructive Criticism on things that are unclear or can be shown in a better or different way is actually appreciated.  I am confident that people of many different skill levels can pull this off, but it is by no means easy.

I hope this guide has helped.  As always comments, suggestions, and questions are appreciated and welcomed.

Good Luck and Thanks for reading!

165 comments:

  1. Thanks for starting this thread. Looking forward to seeing the rest of it.

    ReplyDelete
  2. Caleb, its my pleasure - I wish I had documented it better the first time I did it. I am getting some parts together to replicate some of the steps. It will take a few weeks but I have now finally completed my iMac G4/G5 - mac mini setup and can now turn my attention to completing this guide.

    ReplyDelete
    Replies
    1. JBerg--thank you so much for all the work you've put into this.

      I've had a disassembled 15" iMac sitting around for about a year, and this weekend I decided to finally make something useful out of it. I followed your guide for the 17" TMDS to DVI, and with some more research, I was able to get my 15" working as an external monitor using the native power supply. It looks great. Here are the (almost) final results:

      http://i.imgur.com/uwa4k.jpg

      Keep up the good work!

      Delete
  3. This is really cool! I found a Flat Panel iMac in my schools garbage the other day, so I am hoping to use that. It's a 15in screen though, so I am wondering if it will still work with your in progress guide? The screen and backlight work. In fact, the entire computer works, and booted up into OS X. It's an 800Mhz machine though, so it'll probably get more use after modding.

    ReplyDelete
  4. Unfortunately, no. The 15" has a different pinout. But this has been done before. You can find the pinout on this thread:

    http://forums.macrumors.com/showthread.php?t=224698&page=9

    About half way down pgee70 links to the pinout. I have never worked with the 15" so I can not myself verify it. But this approach is the basis of my 17" mod so I see no reason it should not work.

    ReplyDelete
  5. Hey man your site is awesome, lots of cool mods for the imac,I got a power supply from an old tower that I had and it was a 12v and 3.3v source, I got it off a powermac g4 but my friend was able to get the same supply off a dell optiplex. the trick i to get it to fit inside the dome.

    ReplyDelete
  6. Is this guide finished?

    ReplyDelete
  7. Of course not - its barely begun

    ReplyDelete
  8. first, let me just say thank you. this is amazing. i hope i can even begin to succeed doing any amount of this.

    my question: do you intend to do something similar for the 20" machine? that's the model i have and i'm hoping to resurrect it in some way if i can. ideally i'd love to keep the original lcd of course.

    even if the answer is "no", thanks anyway.

    ReplyDelete
  9. jptxs .... you are very welcome.

    I have to ask you a question. I am thinking of repeating my current 20" mod. This mod uses the guts of a 20" aluminum apple cinema display. You can use either the original LCD or the ACD LCD. This mod is technically more challenging and more expensive. As of now, it requires alteration of the wires in the neck, significant soldering and of course some working components from a cinema display (can be expensive). The advantage is that this is method is very stable.

    I am also going to continue to see if I can "solve" the 20" inverter in a similar method to the 17" Guide. Although I can not give any guarantees.

    My question is - Would the first method be useful to you? If it would, I would document the process for you. However, if you can't see yourself opening the neck, changing some of the wires, soldering them to the existing cables of the the Apple Cinema Display and would wait to see if a simpler method becomes available then I may not "fully" document this process. Let me know.

    ReplyDelete
  10. After reading more of your posts and getting a bit deeper into the machine (have the bottom pretty well unassembled and the bezel off the monitor), I believe I'm going to attempt to replace the LCD screen entirely and then embed a mac mini into the base (along with some weight to make the neck happy). And I think what you have up here now is pretty good to guide me through that. So again, thank you!

    I do have one question, though. I'm a bit stuck trying to sort out how you get the LCD out of the monitor casing. The three screws are out from the bottom and the bezel is off. But I can't seem to get the LCD to come out. Of course, I'm trying to not over apply force. I tried some light prying around the edges and also using suction cups on the front to pull it out. Since I know I'm not going to use it, it's tempting to just force it. But I was thinking I may be able to find someone who would want it (would you? now that I'm thinking about it...) Any guidance for how to lift that out or some post on this awesome imacopedia you've built that i've missed that would help?

    again, thanks.

    ReplyDelete
  11. maybe i've answered my own question. do i need to tackle the neck before I can get the LCD our of the monitor casing?

    ReplyDelete
  12. sorry for the running commentary. i got the LCD out. but those little tabs that were tucked into the slots in the casing were terrible! i got the top and sides out fine, but the grayish/brownish thing that was fit around the actual LCD that had the tabs had to be cracked along the bottom to budge. of course, i may have missed a subtle trick. but aside from that one defect, the LCD is not out whole and the casing is unscathed.

    now i'm in planning mode as i can't make any moves with the mac mini until after the holidays.

    ReplyDelete
  13. Jptxs - I'm glad you were able to get it out. After you remove the bottom torx, you have to push up on the bezel to push those top tabs out.

    A couple words of advice. I do not believe the new Mac mini will fit into the dome. Make sure before you take anything apart.

    Also, I would not recommend replacing the LCD with anything except for the 20" LCD from a 20" iMac G5 or 20" Aluminum apple cinema display. First, 20" LCD's that are 16:10 are hard to find. Secondly, by now you can see the incredibly thin inverter. No other inverter will fit in the case and no LCD controller will fit. Placing these in the base is unsafe and difficult.

    What I've done is used the cinema display's control board to work with the native inverter and it works great.

    ReplyDelete
  14. that's bad news about the LCD. i'm just not sure i have the chops to do all the wire and pin work you describe for things like the DVI conversion and making the power work.

    i wasn't planning on using one of the latest mac minis. i have two here (one of which is about to retire from "active duty") that are 2 & 3 generations back. I was thinking I was going to attempt to replace the optical and HDD for one with drives that mimc the dimensions of the imac's. after removing all the stuff that would no longer be used form the base, i was thinking that just the guts of the mini minus the drives would fit in the base. i still have to validate that i can swap the drives and such, but that was the general outline. complicating this is the fact that i believe that the optical drive from the imac is dead, but need to see about that - i read on line many things about optical drives in the last versions of OSX for G4 going wonky so it may have been software.

    none of this happens until after christmas, though. because if i spend a dime before then the wife will have words to say about it =]

    even if i get to none of that, the odyssey of deconstructing this machine has been a lot of fun. and it would not have been possible without your great sharing. so thanks again for that.

    ReplyDelete
  15. I'm planning to start my 20" mod soon J, took the dome apart yesterday.
    New Mac mini will fit inside the polycarbonate dome & I plan to leave the faraday cage out apart perhaps from the top section to strengthen the neck.
    I do have ACD here but would prefer to splice DVI connector as per your latest guide and use the working iMac display.
    Hope you can solve the inverter.

    ReplyDelete
  16. Roger, it works, see my latest post!! Finally got it to work. To be honest, I don't remember exactly what I had tried in the past, but I'm surprised I didn't stumble upon it sooner. Only pain remains the need for a 24.5V DC line or upconveter. I'll detail my solution soon.

    ReplyDelete
  17. Hi JBerg,

    Thank you so much for putting this together, it's been really helpful. I started working on my iMac G4 15 inch about a month before seeing this article and boy to I wish I could go back. I ended up just cutting through my TMDS cable and hadn't though of dismantling the connector like you've done. Stripping wires of that size is something I never wanna do again :)
    I've got the inverter cable hooked up properly and the display is backlist. I began hooking up the TDMS wires to their places on my DVI connector and noticed the display printing some garble, the hot plug detect seemed to work too, but suddenly nothing in the TDMS cable seemed to work. The screen was backlit just fine, but it seems now that nothing I do w/ the TDMS cable connections have any effect on the display. Could I have burned something out?
    I'm sorta half hoping it's burned out so I can just get a new display and NOT chop the connector off of the TMDS cable. Alternatively, maybe I can get a 17 inch display instead.

    Thanks again,
    Lex

    ReplyDelete
  18. Hey Lex, it is definitely possible, even easy to burn out/damage displays. I can not say for sure that is what happened. Remember even 1 poor connection can give you no image. It may be worthwhile to check with a multimeter the integrity of your connections. That said, you may never me able to get a good connection. On one mod I had forgot to put the dvi connector through the hole so I had to cut and resolder. So now I had 2 solder connections on my wires, despite good signal with a multimeter, I would see pixelation and color distortion. I eventually replaced the entire black iMac LCD cable - with resolution. But, solder connections, changes to different wires all cause changes in resistance. And the black cable in particular is very temperamental. So you my be better off replacing the wire or entire neck from a stability standpoint anyway. Good luck and keep me updated - I'm hoping to see the iMac G4 return to many peoples desktops!

    ReplyDelete
  19. Hi JBerg,

    I took your advice and checked all the connections, and sure enough 2 of them were out of place. Hooked them up and for the first time I'm seeing a my OS desktop! Granted it's a bit fuzzy/flickery but I'm guessing that will be greatly reduced when I actually solder everything back together. I ended up using a small breadboard so I wouldn't have to solder/desolder during my testing phase:

    http://files.roxer.com/user/lex/bdbacbc79683ac8945a84b5706670ac8.JPG

    We'll see how the resolution is once everything is soldered. I may end up replacing the whole wire if it's too distracting.

    By the way, I've already dismantled a new Mac Mini (the one w/o a DVD drive) and it actually fits nicely within the base of the iMac G4. Also, it takes HDMI and actually comes w/ a DVI -> HDMI connector. From what I've read, both HDMI and DVI use TMDS cables but I didn't have the guts to try to go straight to splicing on a HDMI cable. Next time maybe :) My next task is to try to figure out how to get the iMac's built in PSU to power both the screen and Mac Mini guts. So far the internal PSU has been stubborn and doesn't respond to my attempts to jump it. I'll keep you posted.

    Oh, I did have one small question if you don't mind regarding your pinouts diagram: what does 'VCC 5V2A' mean? Two of the TMDS cables require this and I've just been hooking it up directly to 5V from an external PSU.

    Yes, I hope to see these return to people's desktops too. Personally I think it's one of the best computers ever designed. It's the only computer I've ever had that I want to keep around for years to come. If you're ever board check out Steve Jobs' keynote when he introduced it, exciting stuff.

    Thanks,
    Lex

    ReplyDelete
  20. Yes an HDMI cable should work fine. HDMI is just a rearrangement of the Digital pins of DVI + audio. Until i found this DVI connector, I was going to do the step by step with a splice to HDMI. Good to know about the mini. But, make sure it can fit within the faraday cage and not just in the bottom. There are four metal posts which come down to close it. The original mobo had holes in it to accommodate these posts. Also make sure it fits with whatever you need plugged into the rear ports. Even right angle connectors can add significant length. I am still an advocate for smaller form factor boards with this mod, as cooling will be much easier at the top of the dome, but I am def interested in seeing if a new mini can be made to work. So keep me updated!

    VCC is just the voltage required to operate the electronics within the LCD itself. 5V2A just means that my source was 5Volts and 2Amps. Although the panel natively works with 3.3v, I'd still recommend at least 2 amps. I was thinking about using native power source with the 20" mod and I still might. However, I do not have a working Power source and had heard that jumping is not straight forward. So again I'd love to hear how it turns out. Good luck

    ReplyDelete
  21. Hi JBerg,

    Here's a picture of the Mac Mini board placed in the faraday cage:
    http://files.roxer.com/user/lex/60b4f253d7c61fe3ab626fb958062151.JPG

    This ends up blocking just one metal post which is used to secure the original PSU. There's a nice amount of space for things to be plugged into the back of the Mini. The power button is trapped but I was planning on rewiring that anyway. Not pictured is the hard rive and Mini PSU, but they're both very small and can be easily stacked above the board:

    http://files.roxer.com/user/lex/25afa73331c0ed54a3e88322c6065245.JPG

    I've soldered my DVI cable to the HDMI cable. It looks like it's working perfectly except there's a pretty bad green tint. Strangely, the resolution is good and isn't jumpy at all...just a little green:

    http://files.roxer.com/user/lex/3a46d574fc1396193452bf476ffceee2.JPG

    I've rechecked the pinouts and I'm pretty sure they're correct. My next step I guess will be to re solder everything incase I did a poor job on one of them.

    One quick question about ground- as mentioned I'm splicing on a DVI + cable, which means I'm soldering actual wires. Do the TMDS ground wires have to match up w/ the ground pinouts on the DVI side, or can all of the TMDS ground wires just go to any single DVI ground pin?

    Thanks,
    Lex

    ReplyDelete
  22. Looks good, the mobo looks relatively small. Make sure you rewire the wifi antennae to the outside.

    The pins you are talking about correspond to the shields that actually wrap around both wires that make up each signaling channel. TMDS (like LVDS) relies on differential signaling between the two wires. It shouldn't matter, but I would strongly recommend keeping them with their own. Any slight interference will be very magnified.
    Make sure its not just your DVI to HDMI adapter - I've seen plenty of these be faulty. Usually a green/yellow tint is caused by problems with the blue channel which is TMDS 0, pins 9,10,11. I am not sure if the picture is changing the actual color - but it looks like a dark green. This may be indicate problems with both the Red, TMDS 2, pins 1,2,3 and Blue channels. Hope this helps

    ReplyDelete
  23. Hi JBerg,

    I ended up starting fresh with a brand new neck and wires. This time around I properly disassembled the end of the TMDS cable and connected the end pieces to the same deconstructed DVI connector that you're using. Carefully checked everything and am getting the exact same green tint again :( I'm guessing this means the display is bad; perhaps I messed it up w/ my first round of work. Anway, I'm gonna try replacing just the LCD screen and see how things go. Wish me luck!

    Thanks,
    Lex

    ReplyDelete
  24. Lex, I'm sorry to hear that. But, it does appear that it is the LCD. If you applied voltage and a ground to the wrong pins, you can certainly damage the lcd.

    How do you like the DVI connector? It took 2 hours of work and compressed it into 20 minutes for me. Once your connections are set you could either solder (depending on your comfort level) or use hot glue. Just don't let successive pins touch. I used hot glue to secure it after using small pieces of electrical tape to shield the image pins. If you have a hot glue gun it works perfectly.

    Anyway please keep me informed and good luck!

    ReplyDelete
  25. Hi JBerg,

    Oh, the DVI connector made a world of difference, I'm really happy that I read your post. Everything just snaps into place perfectly! It's the best $2 I've spent in awhile. I spent maaaany hours the old way labeling wires and individually soldering them together and it just turned into a huge mess. Yeah, the DVI connector route was took me about 30 mins too.

    I'm absolutely horrible at soldering, so I'm gonna go with the glue gun. Thanks for letting me know about shielding the image pins, I'll be sure to do that.

    By the way, I have a 3D printer being shipped to me as I type this (makerbot.com). Using Google SketchUp I'm actually designing custom housing for the new iMac innards that I'm putting in. This will nicely hold the Mac Mini board, accompanying components, wiring, and an Arduino. It can then be mounted internally using the same screws that the original motherboard used.

    I'll post some pictures when I print my first prototype :)

    Lex

    ReplyDelete
  26. Lex, that sounds incredible.  I can't wait to see your design.  I get asked by people all the time about fitting Mac minis into the dome.  If you produce a product, I would be happy to refer people your way.

    I actually think its best not to solder.  There is too high a risk of causing cross talk.  The hot glue works great, it insulates, secures and you don't have to be perfect.  As I mentioned though, before you glue, turn on the LCD.  Open up web pages with different colors, play videos etc and look all over the screen for any sign of flickering pixels (usually red or green) - this indicates cross talk. While the glue Gould technically seal everything off, it is really too viscous to get between every little seam and once it's glued - there is no turning back.  So use the small pieces of electrical tape around the signaling pins.  Once you be made sure there is no cross talk - go ahead and glue it.  For the final wrap I used aluminum tape to give the cable some "rigidity".

    Looking forward to seeing your work.  Myself, I'm done with all major wiring, I am waiting for a broadband card and have work to do on the ports.  Keep me updated, JB

    ReplyDelete
  27. JBerg, great work you have done here! Thank you very much, you saved me a lot of time.

    I am about to use your mod to make an 17" iMac into a display, I am using an old AT powersupply to power the inverter. Since the voltages are quite high (about 16 volt on the "12v" line, 7 volt on the 5 volt line) I am planning to use fixed voltage regulators to produce the 12v resp. 3.3v.

    Have you measured how much current the display draws on those lines? That would help alot picking the right regulator.
    I would go with 1A but 3.3W + 12W = 25.3 Watt seems to me little for a display.

    Cheers,
    Nils

    ReplyDelete
  28. Nils, thanks for reading and happy to help. Unfortunately, I have not measured the current in the 17" version (I no longer had an original working version). However, I have always targeted power sources that supply 2A for this. the average 17" LCD consumes 35 - 40 watts, so I agree that 1A may be somewhat low, but I can not say for sure. Hope this helps, JB

    ReplyDelete
  29. Thank you for your reply JBerg.

    To answer my above question:

    The display draws about 0,65A on the 5V line.
    I ended up hooking up all 3.3V lines on 5V as well.

    Sleep did work the way you describe when the connected computer really went into standby. When it was running but hte laptop screen was turned of, the backlight of the iMac screen was still on.
    Even though when I turned on the iMac screen while the laptop was already running, it wouldn't turn on. So I decided to give up the idea of a sleeping display.

    Are there any projects handling the dimming? Couldn't find anything useful on the internet.

    Next project will be an integrated MacMini in the foot as Lex was suggesting it above.

    Still looking for an 20" iMac - but as you said they are pretty rare. :-/

    Cheers, Nils

    ReplyDelete
  30. Nils, did you connect the Red wire of the inverter to the splice of the gray cable 's red/hot pink and the VEDID? This should cause the backlights to turn off when the monitor doesn't get a signal. The brightness can be controlled by a PWM controller with the proper voltage. You can buy these or you can fashion your own like JL7 did in his original cinema display mod. His site is in German, but you can run it through goole translate or just ask him. He has been a great help to me and writes perfect English. His site is www.brennecke.org. Hope this helps and thank you for letting me know about your success, it's always great to hear. - JB

    ReplyDelete
  31. First of all, JBerg, thanks for you great guide. Based on it I got a 17" (1Ghz) imac's screen to work. I used the iMacs native power supply to provide a pico-psu with 12V, because – if I understand it correctly – the iMacs native psu does not have a 5V line. It provides 12V to the imac mainboard, where it is converted to 5V and 3.3V. It also doesn't have to be jumped as it is always on. This all seems kind a strange to me, but measuring the output voltages and searching the internet seems to confirm it. In any case, it works fine the way I did it.
    I had one question however, do you know what the correct voltage is for a PWM controller for controlling the brightness?
    Thanks again,
    Jelmer

    ReplyDelete
    Replies
    1. Very interesting information about good old design units...
      One question to you for all of us not so familar with resoldering etc.
      What about ready done and configurated cables/adapters from your side?
      With that user with less skill (like me) would be able to unplug the cables from the logicboard and easily able to plug the lcd cable into your ready done adapter for the use as a DVI device.

      How does it sounds to you?
      For me, it would be the easiest way to stay alive with such a kind of unique computer system and hopefully the mini conversation will be workable and hdmi will be on the run for an intel based lamp... Dream need time to come into reality.

      Looking forward to it.

      Cheers and thank you for your nice job and share it with us.

      Delete
    2. Jelmer, I was just reading through old comments and saw yours. I have been playing around with the native PSU of the 20" and you are spot on. DC-DC downconverting seems to be done by the iMac's mobo and the PSU seems to be for the most part a 12V only PSU (actually somewhat ahead of its time). The only other thing I would recommend is using a 12 to 5V dc-dc downconveter instead of having to add an entire PICO PSU complete with power brick. If you need 3.3V you can get a 12V or 5V to 3.3V downconverter as well. The motherboard itself probably has DC-DC downconverters on it, but they cost only a few dollars and can be quite small.

      Delete
  32. Hello,
    I want to do this mod on a 15" mac but will it support HDCP??

    Cheers and thank you for all your nice mods ;)

    ReplyDelete
  33. I have the 15" pin out courtesy of pgee on my blog. I can not say for sure, but on the 17" and 20", I have not had any problem with HDCP. Thanks

    ReplyDelete
  34. Hey,

    I really appreciate your Guide.
    I Got a question. Do you have an engineering drawing or something for the DVI-Connector.
    I found one at a German Shop but I don't know, whether they match your connector.
    Here is the connector: http://www.rm-computertechnik.de/Shop/2522_DVI_Einbaubuchse_24_1_Digital.html
    and here are the drawings: http://www.rm-computertechnik.de/Shop/picturesbig/2522-DVI-24-1-90-Grad-Zeichnung-1.jpg
    and http://www.rm-computertechnik.de/Shop/picturesbig/2522-DVI-24-1-90-Grad-Zeichnung-2.jpg
    I would be glad, if you could provide me with the drawing for your connector or if you could check mine, whether it fits the build.

    Thanks in advance.

    ReplyDelete
    Replies
    1. Here are some data sheets. There appear to be some differences, I do not know if they are significant. The most important thing is if the pin fits easily yet securely.

      DVI data sheet:

      http://datasheet.octopart.com/74320-4004-Molex-datasheet-60256.pdf

      http://datasheet.octopart.com/74320-4004-Molex-datasheet-144253.pdf

      hope this helps and good luck

      Delete
    2. Thanks a lot for your help.
      I checked the drawings and the only important difference seems to be, that on your connector the space between the pins is 1.91mm and on the one I found 1.905.

      I really appreciate your work and help.
      I will try to accomplish your guide in the following weeks.
      And one last thing. I wasn't able to post using the "Name/URL" profile.

      Thanks.

      Delete
    3. I just found out, that posting doesn't work on the first click.
      After the first click on "Publish" it displays a red rectangle. I have to click publish repeatedly for it to post.

      Delete
    4. Brian, thanks, its my pleasure. I am confident your connector will work fine. thank you for letting me know about the post/publish problem. I have decided to alter/simplify my blog and hope this helps the problem. Thanks again.

      Delete
  35. you know any where where we can still buy this female dvi connector you used? i cannot seem to locate one...

    ReplyDelete
  36. This is not the only type of DVI that will work, I'm sure other variations with the same pin width/thickness exist, but this is the one that worked for me. When I google the part number I find 4 vendors. Allied Electronics, Newark.com, Onlinecomponents.com, netsemi.com. Prices are $3 - $7 for 1. Onlinecomponents for instance lists a little under 2,000 available for $2.89

    ReplyDelete
  37. I tried my best to follow your guide, but I am not getting any picture, the backlight is on, but just a white screen. Windows sees it as a monitor and calls it "color LCD" with a recommended resolution of 1024x768. Any advice? Started with. Fully functional

    ReplyDelete
  38. Did you use te DVI adapter? What resistors did you use? How did you make the extra wires? Are you sure your neck is the correct one?

    ReplyDelete
  39. i severed the end of a DVI-D cable i had and used that. I used 1k ohm 1/4w resistors i got from radioshack. I used extra wires from the fan connector & speaker to make the extra wires. I have the 15" g4 & used the pinout sheet that you recommended.

    ReplyDelete
  40. Sorry to hear about your difficulties. I have never myself done the 15" but several people have had success with that pinout. Use of a severed DVI cable is not te method I recommend for 2 reasons. It is very easy to have a poor connection and secondly all the pinouts are based the official DVI pin numbers which are based off of a FEMALE CONNECTOR. If you used a severed DVI cable this is a MALE interface and the pinout will appear different, so you must take this into account.

    ReplyDelete
  41. Hi - Many thanks for this - Just about to start converting a 1.25GHz 17" which died. just ordered everything from Ebay and Amazon to complete.

    I'd like to be able to easily turn on / off the display and came across this as a swtich for the molex power supply - http://www.ebay.com/itm/4-Pin-Molex-Extension-Sleeved-Cable-w-On-Off-Toggle-Power-Switch-/120843238850?pt=LH_DefaultDomain_0&hash=item1c22d17dc2

    Any thoughts - its difficult to tell form the picture but appears it may only switch the 12v line

    ReplyDelete
  42. PS If anyone is looking connectors are available here

    http://www.ebay.com/itm/230744344088

    ReplyDelete
  43. Chris, it's difficult to say for sure what it does based on that picture. But, I agree with you the rocker switch likely closes the connection for the 12V line, which would turn off a standard molex powered device. For this mod, opening the 12V will turn off the backlights (as the backlights themselves will loose power). However, the LCD itself will stay on (if the source is outputting). To turn off everything, having the 5V line attached to the switch would probably be best. This would cut off power to the LCD and the on /off of the backlights. So you could easily add your own rocker switch, buy this cable and switch the rocker to the 5V line (it's only $4), or leave it alone and be fine with just the backlights turning off. What are you using as your source/computer? What is your power source?

    ReplyDelete
    Replies
    1. Thanks - if all I need to do is switch the 5v line I can do that with a simple radio shack switch.

      I picked up a standard 5/12v molecular brick adapter from amazon.

      I'm going to see if I can get the hack to work vanilla first and then I can add the switch etc.

      If all works I may then look to add a mini-itx motherboard or based pc in
      The

      Delete
  44. Hi JBerg! Your blog is very inspiring! I got an old iMac G4 17" and were thinking of following your guide. You write that you use a DC to molex power supply and a molex splitter. This seems very practical, but I were thinking of also include a DVD or BluRay-player in the base and have found a three-way molex splitter. But will the power supply manage this? The spec of the one I found are:
    Max 12 V: 2A
    Max 5 V: 2A

    ReplyDelete
    Replies
    1. I have a similar device and it powered the 20". So it should be fine with the 17" and bluray.

      Delete
  45. Any ETA on the 1.25Ghz video / guide? Almost all of the parts here. Cheers

    ReplyDelete
  46. when you add 1/1.25 Ghz tutorial?

    ReplyDelete
    Replies
    1. The mod was completed successfully tonight. It will be posted shortly

      Delete
  47. I have none of the tools required nor do I have any experience tinkering with electronics, but this tutorial is so detailed and clear that I am tempted to give it a try.

    Would this work for a 700 MHz iMac G4?

    Congratulations on your site!

    ReplyDelete
    Replies
    1. Thank you so much. That is what I've been striving for! I wanted to do this mod in a way that most people should be able to reproduce. I have a video tutorial that will be posted soon.

      The 700mhz was the 15". I have never done it, but a fellow modder Pgee70 has and with his permission I posted his pinout on my blog. The concept are exactly the same, just which color goes where varies.

      Delete
    2. Thanks! I'm going to read all of this a few more times before I get started.

      Delete
  48. hi JBerg,

    when are you going to put the part of the 1/1.25 version on the site??
    I can not wait to begin this mod ;)

    ReplyDelete
    Replies
    1. I completed my video tutorial tonight. I just want to look through them and will post in next 24 - 48h.

      Delete
    2. if you could translate in polish will be nice english is good but i don't understand everything maybe you should add some list of parts which you used to conversion i don't wanna destroy my imac g4 committing some mistakes. i have good imac g4 but i want to do conversion lcd to dvi and change motherbord with intel processor and instaling windows xp on it :)

      Delete
    3. Sorry, I promise you that your english beats my polish.

      Delete
  49. can it's possible to add powersource from motherboard ?

    ReplyDelete
    Replies
    1. Makin, I assume you are asking if its possible to add the native powersource . It is but you need to give a 5V line to it. I will have a post concerning the native psu sometime in the near future.

      Delete
  50. can will be more tutorials for 1 /1.25 ghz or thats all?

    ReplyDelete
    Replies
    1. The video is completely done, I have posted what doesn't need to be broken down or edited. The remaining parts will be posted shortly.

      Delete
  51. could you please recomend me some cheap motherbord with intel which should be match to this faraday cage :)

    ReplyDelete
    Replies
    1. Remember, nothing really matches this faraday cage, but I recommend small motherboards such as nano, pico, or my favorite ECX. I have used the KEEX-4030 and the KEEX-6100. These are not particularly cheap.

      Try quanmaxusa.com (they have some refurbished ECX/3.5" boards on their site) or sliger.com which is a licensed quanmax dealer with fantastic, personalized customer services. If you google ECX motherboards you will also find other dealers and manufacturers.

      Delete
  52. JBerg,

    Thank you so much for the TLC you put into this guide. I was able to successfully reterminate the TMDS cable from my 17" 800Mhz iMac into a male DVI plug from a cable I cannibalized. The signal worked beautifully for a while, but after a day or two developed noise throughout the image -> green and blue sparkles that increase in intensity as the color of the image gets closer to black.

    Don't worry, I'm not asking for a diagnosis, I already know that this is probably due to one or more cold solder joints. These teeny cables are nearly impossible to work with on a good day, and the added issue that solder changes the resistance of the circuits by minute amounts - there's no telling which joint did what damage. It's a miracle that I don't have a solarized picture or that there's even an image at all!

    I decided to buy a new neck from macpro.com, very inexpensive - only $45 shipped. Also, I identified the manufacturer's designation for the DVI connector you used. It's a MOLEX 74320-4004. Mouser.com has 150pc available at this time and they're going for a bit under $5 a piece. You might want to add the part number to the guide so that people know exactly which connector to buy, since that eBay auction ended ages ago and the seller doesn't always carry the connectors. Only molex makes this connector with the tiny pins, it's not a standard configuration, their name brand for it is "microcross," if that benefits anyone.

    Thank you so much again, JBerg.

    -btzmacin

    ReplyDelete
    Replies
    1. btzmacin, you are very welcome. This is similar to a problem I had with an earlier mod after I had to cut a resolver, except green and red "sparkles" would appear. Even when I thought I had corrected it, when certain colors appeared I would realize they are still there. I have not had any problems like this since I started using this DVI connector. I had not realized that I did not put the part number in this post. It was in my post when I first found it and my video, but I agree it should be mentioned here. And thank you for the additional information. Good luck with the new neck and wait until you use the DVI connector, I simply can't say it enough, it literally takes all the frustration away, and saves you hours. Enjoy!!

      Delete
  53. but how to connect new motherboard to old powersupply from imac g4 ? ;/

    ReplyDelete
    Replies
    1. This may help: http://www.youtube.com/watch?v=RUrRQydWW2Q

      It was posted by the same Pgee70 that JBerg mentioned earlier in this thread. iirc, Pgee70 did this before he figured out to connect to the iMAc's LCD

      Delete
  54. I'am having a problem closing my imac G4 arm back up. I can't remember the position of the 4 thin metal washers that go by the pivot points. Please help.

    ReplyDelete
  55. The metal washers center bulges outward if I remember correctly. So it looks sort of like an upside down U. Hope this helps

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  56. This comment has been removed by the author.

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  57. I accidentally connected 12v to the red, blue and yellow wires on the grey LCD cable and now it wont darken the screen like before, did i ruin the screen?

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    1. Kodie, I can't say for sure, but it is possible. Was anything grounded (hooked up to a black molex) when this happened? It is surprisingly easy to damage the LCD and inverter. Hook up the LCD without the backlights on, you should be able to make out an image even if it's dark. If there is an image, it may only be the inverters on/off that was damaged and may need replacing. Before buying anything though, triple check all your connections. Good Luck

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  58. Hello,
    I've visited your site quite a few times and i noticed today you have this step by step guide, which is extremely helpful. I plan to turn my iMac into an external display this summer.
    Keep up the good work!

    -Tanner

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    1. Tanner, thank you for the kind words. Good luck with your project and let me know if anything is unclear.

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  59. hello can this lvds from compaq will be good ? http://allegro.pl/tasma-matrycy-compaq-evo-n600c-6017a0016501-i2267867425.html

    ReplyDelete
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    1. Its impossible to tell the gauge or pin size from the picture and info

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  60. Have you posted yet about using the native PSU? Not sure if mine is dead or I am just doing it wrong.

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    1. No not yet. How are you using it? The 12v are easy to test, I can even get the 24v on the 20" PSU working. It's the 5V that's been a problem. On the puss motherboard connector, you should see a bunch of yellows in a row (4 or so). Plug the PSU in and take a multimeter, connect the positive to one of the yellows and the negative to one of the black wires on the connector. You should have 12v dc if the PSU works

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    2. Using the native PSU has been posted for the 20"

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  61. excuse me how to properly protect DVI connector with all this wires after doing everything? they are very thin and you can very easily damaged so maybe pour something this connector any idea?

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  62. Hi I was wondering if pico PSU 160W with 105W power supply is adequate to power the display alone?
    I can only find this combination in where I live and any power supply with 120W+ is not easy to obtain.
    http://www.linkecomputer.com/products/1011329/PICOPSU-160-XT/Mini-Box/

    Also, is there any update on using the 17" native PSU? If there is any good news, I can save some money :)

    I'm trying to mod an iMac G4 17" 1GHz to accept DVI input, then will try to fit a mac mini/hackintosh into the dome.
    thanks so much for your contributions on the iMac G4, I'd never thought about doing something like this until I stopped by your blog. :)

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    Replies
    1. You are very welcome. I am not sure if you've seen this already, but my 20" iMac g4 mod uses an ECX board with a core i5 dual core running lion via hackintosh. This remains my recommendation for all in ones at this time. The Mac mini in the dome is something I have not pursued. The primary reason is that the board of the new aluminum ones are rather large. I have seen a picture of someone wedging it in at an odd angle. However, some ports appeared blocked and this didn't account for the power source and hdd. I have a 20" iMac G4 hooked up to a new mini externally and I really enjoy this setup. The base provides the optical drive that apple did not include on the new mini. If you are ok with the older plastic ones, cooling may be difficult, but this is definitely doable.

      The answer to your question is yes that will power the display. However, do not buy it. I have looked at the 17" PSU and similar to the 20" it is an "always on" PSU. There is one detail I have not fully worked out but you should not waste money on another PSU. The moment you plug it in, the yellow wires are live with 12v, the blacks are the grounds. I was expecting the lone yellow at the end to not be live until something else happened, but it was. There is no white wire, only a blue. I haven't checked yet, but grounding the blue may even turn off the lone (possible display power) yellow. I will check tom and let you know. Since the display is turned on and powered by 5/3.3V and this came from the motherboard, you will need to simulate this. So you will need a 12v to 5v dcdc downconverter of some type. If you use a motherboard like the ECX or some nano itx, they only require 12V (use a P4 connector). Also they have on board downconverters. The ECX has a mini-Sata power/Molex out. So by cutting a yellow and black wire from the PSUs motherboard connector you now have 12V to give to the motherboard which gives you your 5v line. So with the molex out 12v and 5v line, complete the mod as you would have above. If you are only using the LCD, you will need to buy a 12v to 5v dcdc converter (see native 20" PSU post). If you are using a Mobo that requires an ATX plug you should use a pico itx PSU, but supply the 12v dc in from the native PSU not the power brick. I will have a post on this soon. Hope this helps.

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    2. Thanks for your reply. I looked at the dimensions of iMac G4 and the current gen mac mini after looking at your reply, seems like it really won't fit into the dome. That means I might go for the external mac mini approach.
      I'll go for the 12V>5V downconverter approach, and will investigate into the native PSU when my iMac G4 arrives.
      Thanks again and I'll talk to you soon. :)

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    3. Just one more questions,, from your post on 20" native PSUs, if I will need to power the display only, do I need to purchase the downconverter? or I can provide the 5V from the DVI source?

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    4. I do not mean to discourage you or say it definitely can not be done. I myself have never opened up the new mini and tried to see what can fit where. I am only offering advice from my own experience. There is a high risk of irreparably altering or even damaging the mini in even attempting to do this with a relatively low chance of long term stability. My current setup uses the new mini with dual converted external monitors - 20" iMac G4 (a slightly different method) and 20" iMac G5. I used the G4 base for a USB DVD burner and the iSight from the G5. There is this great under desk mount with front facing USBs that I use which makes the mini almost invisible. Also, upgrades and alterations are a snap, you don't have to take everything apart just to change your speakers. I personally have not regretted having the mini external at all.

      In terms of the downconverter, yes you do need it. The DVI input is low power which means that the 5V has low current/amperage. It is intended to be used by the LCD as a switch not really as a power source. Although it is split multiple times (to the Hot Plug Detect, the backlight on/off, and (for the 20" native PSU) the PSU 24V on. While this seems like a lot, these are also just switches, minimal power is actually used. The 20" LCD panel itself is powered by 12V and the backlights use 24V which is turned on via the PSU switch which is the only place where 5V is needed, thus the DVI source suffices. The 17" LCD panel is actually powered by 5V(3.3V) and there is no switch (so far as I can tell) because the 5V also turns the backlights on/off via the RED wire which comes from the motherboard, thus the does not need to involve the PSU at all which keeps the 12V always on.

      Sorry if this is confusing, but to put it simply, 5V is needed for actual power in the 17" (The LCD itself and possibly part of the backlights), not just to turn on a switch. I am fairly certain that this would overtax the 5V DVI VEDID and would not even try it as this could damage the DVI source (the computer you hook it up to. Good Luck.

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  63. hello i have a problem a was bought cheap chinese adaptor exactly like mollex but now i don't have a voltage between points 3-4 6V and 3-1 12 v . when i checked by multimeter i have only voltage 6V between points 1 and 4 what's wrong.?

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    1. I assume you are referring to the 4pin molex connector. The yellow-black-black-red 12v/5v cable. I'm not sure what Chinese adapter you are referring to however. The connector itself doesn't matter, the cables have whatever you supply them with. What are you using for a power source. It seems you have the the yellow connected to 5V (?6v) and red connected to ground. I can not say if blak is attached to anything or not. A picture or description of our setup may help me better understand.

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  64. hello by mistake i connected ground to empty slot on my adaptor :( and i don,t have nothing lcd is black when i try to connect inverter part 5 your tutorial so probably this is end for me i presumably damaged something ;/

    ReplyDelete
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    1. While it is possible you could have damaged something, make sure to check all your connections again.

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  65. Hello i hooked up the LCD without the backlights on, and i see an image but yeasterday i hooked up the LCD and everything was alright backlights on working for the moment till i disconnected power thats weird.

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    1. I'm glad you got an image, but I'm sorry I don't understand what you have written. I am not sure what you are asking.

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    2. Today I have no backlight when i use flashight i see the image Yesterday I had the backlight until i turned off the power ! Everything is connected !

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    3. i take some photos maybe this help you ! http://imageshack.us/g/834/img1298h.jpg/

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    4. another photos here http://imageshack.us/g/205/img1304hg.jpg/

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    5. What do you have the Red Inverter Wire Hooked Up To?

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    6. helllo i hooked up red inverter to the split ( Pin #14 and resistor) i see image on monitor but no backlight :(

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    7. The 5v should NOT be going through the resistor. The voltage via resistor is for pin #16 only. No resistance should be between pin 14 and here.

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    8. yes red from inventer is connected to vedid before the resistor

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  66. I've got it set-up and working but I do notice crosstalk, how can I troubleshoot? It can only be at the pins 1, 2, 3, 9, 10, 11, 17, 18, 19, 22, 23, 24 right? Or is the damage done now? Can it also be the DVI-connector itself? Cause I've got plenty of those now. Or even the cable? If I look at the pins they do not seem to touch at all..

    http://www.youtube.com/watch?v=1SCuIV-ayCs&feature=plcp

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  67. Thank you for the video - that actually helps a lot. That is an awful lot of noise. It looks almost like electrical interference. To start make sure that the DVI connector is not right next to the psu or molex wires. Try to keep anything with high current 6" or more away from the open DVI connector. And make sure the grounds are well secured. Remember this can happen along the entire length of the connections, so electrical tape up any non-DVI connector connections. Move the DVI connector itself and see if this changes anything. Look at the pins straight on and make sure nothing is bent or too close together.

    Assuming this doesn't help and the problem is at the level of the DVI connector itself, the most likely culprits are interference from the control wires (Pin 14, 15,16) on the neighboring TMDS signals. (Everything is very low current at the DVI Connector so you do not have to be overly cautious). With the screen on and everything hooked up start manipulating the wires and looking at the screen to see if the pixelation goes away. Do not remove the pins, but (starting with the control wires) , gently hold the wire taught and move it from side to side. If this does not work, use your finger to press down on the TMDS pins themselves, press firmly across them. (You are now using yourself as a ground to divert the crosstalk). You should see things clear up. Start compressing a smaller and smaller area to focus on where the problem is. There can be multiple areas. You may need to (very slightly and gently) bend the pins away from the interference. Although its a slight pain, you can cut small pieces of electrical tape and wrap it around the problem areas to insulate them. Although the hot glue will serve as an insulator and will help eliminate crosstalk, its almost impossible to get it in between everything and once its done its permanent. So, I advise trying to eliminate this before finalizing the cable.

    I don't see anything to suggest permanent damage. Although I can't say for sure, its unlikely the DVI connector itself, but if all else fails and you have extra, there is no harm in trying to change it. Hope this helps.

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    1. Thnx for the quick and thorough response, I do have a picture of my current set up. I tried to have it as compact as possible, maybe I'll start with unsoldering everything and use some crocodile cables to get more distance. However will let you know my progress!
      http://dl.dropbox.com/u/30218151/Picdump/iMac%20G4/IMG_2563.JPG

      Jeroen

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    2. After a bit more isolation it seems to get less, however, it's still there. The first minute nothing is wrong but after that the pixelation starts, I can't figure out what it could be. I really tend to use the hot glue after messing around with small pieces of electrical tape. Pressing on the pins themselves doesn't really seem to make a difference. Well I'll wait for my cables and hook it up with crocodile connections and a bit more distance in between power and signal cables. Could the ground of the PSU be the problem?

      Jeroen

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    3. We're getting further, changed the DVI cable to a HDMI cable and HDMI to DVI connector in between, the pixelation is gone. Although, I thought so, after half an hour at certain grey colors it shows again (tiny bit). Isn't it strange that it only occurs after a while? Could it be the powersupply? Or that it isn't grounded good enough? Or should I be happy with the result as you don't see it from a working distance? Could it be a problem with the graphical chip (Intel HD3000)?

      How it looks now: http://dl.dropbox.com/u/30218151/Picdump/iMac%20G4/IMG_2667.JPG
      Awesome :) Thanks in advance and thanks in general for all your effort.

      Jeroen

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    4. You really should be able to eliminate all of it. When its on, wrap your hand around the middle of the metal neck, does thus do anything? Next wrap electrical tape around all the black wires tmds signal triplets. Take little pieces put them around the individual pin and press the sides together so they make a tag sticking out. Then take a long piece and wrap it around the entire dvi connector where all the pins meet the connetors pins. I doubt its the psu or board, but I can't be sure. Let me know thanks and good luck

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  68. please add tutorial how to repair broken inventer ! i don't have money for new inverter !

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    1. Would if I could but I don't know how, the inverters are custom and do not use stock parts. Plus, it may not be repairable. Keep your eyes out, I have seen these old computers being thrown out or people giving them away.

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  69. yeah but shipping cost is expensive from usa ! i think maybe my inverter has defective capacity and it shoud be easy to repair

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    1. Its certainly possible, keep in mind this is not a typical inverter and the capacitors are pushed and glued flat which makes them difficult to examine. Good luck.

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    2. hello i have 17 imac g4 1 ghz can i have use inverter from imac g4 15 ? this is the same ? any difference?

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    3. The voltages seem the same, but physically they could not be more different. Ive never used the 15" inverter so I can not say for sure.

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    4. i found only this cheap inverter on auction http://allegro.pl/inwerter-do-apple-ibook-g3-g4-i2525009665.html

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  70. Thank you so much for this fantastic guide! I have now with the help from you managed to give my iMac 17" new life! I would never have pulled this off without this guide!

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    Replies
    1. Alex, you are very welcome. I appreciate you letting me know about your success as well. Any advice, tips, or parts of my guide you felt could use some revision would be welcomed. Happy to help and enjoy your "new" iMac

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  71. WOW - I have Googled for days to try and find something like this, unfortuantly this is well beyond my technical skills. I think I will be showing this page to my friend and asking him to do it for me !!

    If anyone fancies taking on this project (UK) for me , I will of course pay postage and costs please holler lee at nixta dot co dot uk.

    Dremel Junkie (JBerg) you are a legend !! I write lots of guides for other sites, but this guide truly covers everything, as a guide its inspirational. Many thanks!

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    1. Wow, thank you so much! Its my pleasure and Ive been delighted to see all the success people have been having. Once you get going, you may find it easier than it looks. Good luck to you my friend and let me know if you need any technical support along the way.

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  72. Hello guys, wondering if someone could help ! I am following this tutorial but i'am stuck at the inverter i have a 15 inch Imac and when I switch it on to check the backlights they go on and off again they do not stay on...any sugestions ?

    ReplyDelete
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    1. Everything is working except for the inverter backlights, they go on and off..nobody to help ?
      thanks

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    2. You have to tell me more about your setup. So you are getting an image on your screen, correct? What are you using for a power source? Do the backlights turn on when the screen isn't connected at all? Did you use the 15" pinout? Did you change the Red to the final position or is it still in the test position? Is something grounding out? Have you checked to make sure nothing is touching even the frame of the monitor? Are you using a 1Kohm resistor with the green wire?

      Hook everything up. Disconnect the green wire, what happens? Reconnect it, what happens? Do the same for the red wire. I have not done the 15" mod but the concepts are the same. Trouble shooting can be difficult with these mods, but I can not help without knowledge of your setup and what youve tried so far.

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    3. Hi, first off all thanks a lot...
      Yes i get image screen from an mini mac, but no backlights.
      Powersource = have 2 a pico an a tx computer source tx is the one i am using to test. there is a 3.3, 5.4 and 12 volts.
      if the screen isn't conected then the backlights are on for a second and they go off...so I am actually stuck at the test of the ineverter without connecting anything else. yes 1kohm resister on green wired.
      Ok what happend if i powered the tx with the on/off switch...backlights go on and off again, if i connect/disconnect green wired nothing happends, if i disconnect/connect the red wired then backlights go on and off...I was wondering you telling about GROUNDING out....strange is that if i take the black wired with my multimeter and touch the case/frame i do have a connection...and thats weird (or not) is the inverter ground to the frame ?
      Dremel thanks a lot for your time and help, i would like very much to have this 15 imac going on...also this imac was working before a took at apart...
      If you where closed to Holland i would buy you a beer or two...thx mate.

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    4. did somebody fixed this problem? I also have a 15 inch and don't want to damage something when hook it all up.

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  73. Hi, what a great tutorial, but I'm wondering if this method would work with my 17" G5 screen, LG-Phillips LM171W02 (A4) (M1). My plan is to re-use my old G5 screen and external plastics as a housing for my Raspberry Pi, a sort of PiMac!!
    Thanks

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    1. Absolutely! They are in fact the exact same panels. The pinouts/specs for this panel (and the rest of the A4 series) can be found here if you need:

      http://www.beyondinfinite.com/lcd/Library/LG-Philips/LM171W02-A4.pdf

      I am not familiar with the 17" iMac G5s internals, but the problems you mayrun into include physical conversion of the wire. What made this mod so much easier was the use of the DVI connector as the TMDS wires were frustratingly difficult to work with and solder. I do not know the physical makeup of the cable that connects to the 30 pin JAE connector. For instance that cable could be a ribbon cable, which would be very difficult to work with. In theory if the cable is difficult to work with you could remove the LCD cable from the of a 17" iMac or make your own from a JAE connector, pins, and a DVI/HDMI cable. Obviously, you'd have to use the cable position and not the color that I use here for the G4's wires.

      The inverter I assume would also work very similarly, but I can not guarantee it. Good luck and let me know if I can help further. It'd be great to see pics of the finished products when you are done. Thanks for reading!!



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  74. The G5 TMDS cable is similar to the G4 cable, but the connector to the Logic board is somewhat different. It is not a ribbon cable, so I think your mod should work for me. The G5 inverter is also different to the G5 in so as much the inverter has a different interface to the Logic board, I have found a pinout for the inverter and it is similar to the G4 inverter.
    I am also planning on using the stock G5 PSU to power this mod along with the Raspberry Pi.
    Thanks again.
    Andy
    P.S how do I post photos?

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  75. Sorry, that should read: The G5 inverter is also different to the G4 in so as much the inverter has a different interface to the Logic board, I have found a pinout for the inverter and it is similar to the G4 inverter.

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  76. A quick update: I have successfully powered up my G5 inverter and the back lights are working.
    I have a contact here in the UK who is willing to undertake the TMDS to DVI conversion for me.
    Over the course of the weekend I intend to have a go at powering the backlights via the stock G5 PSU, wish me luck!!

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    Replies
    1. Glad to hear. I don't think you'll have too much of a problem with the native PSU, but with apple products you never know. Good luck and keep me updated and let me know if I can help.

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    2. Hi there, I have successfully powered the back lights from the G5 PSU, so that is good.
      I have received the modded TDMS cable back from the guy who did the work on it, and unfortunately it is not working quite right, when I connect it all together and boot up my Raspberry Pi all I get is a blue screen with vertical line down the middle, so something is wrong somewhere, any ideas?
      Thanks
      Andy

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    3. Its really hard to say obviously something is either not hooked up right or a bad connection. I think you need to break out the multimeter on continuity setting and check the integrity and order of each connection.

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  77. Hi there, fantastic site you have here.
    Even more fantastic, you seem to answer all the comments for the past few years!
    Anyhow, I'm working on a 15" iMac and I'm up to the "extra wires" part.
    I have a few questions.
    1. What are these "spare" cables inside the computer? I don't think I have anything like that. The pins from the speaker and fan cables are too big.
    2. Since I don't know which cables to cut, do you have a recommendation to an ebay seller of appropriate LVDS cables? I seem to think you recommended "nyjtouch" for some reason.
    3. I am working from the pinout from a Japanese site (the colours from the one you posted don't match my machine). http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&eotf=1&u=http%3A%2F%2Fhidekyan.cocolog-nifty.com%2Fblog%2F2009%2F08%2Fimac-g4-dvi-3-7.html&sl=ja&tl=en
    If you had the chance to take a look at the pinout diagram, my understanding is that the male pin your cable splice thing with the resistor would go into the my Lavender cable. Does that seem about right? Which brings me to yet another question, what cable has the male pins?
    4. Finally, the shielding seems a bit stripped for some of my wires. I tried to be as careful as possible, but I think it was a little brittle due to age. Do you think it would be a problem at all?

    Thanks!

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  78. Hi Jon,

    Well I have to admit you made a big work with your website and all experience that you shared. Congratulations and thank you.
    I'll be happy to donate you. Please post a link to paypal if possible.

    I'm trying to do the following: imac G4 17" mod with its own power supply with a Macmini 2.53GHz.
    I followed your instruction to connect the inverter and the LCD cable and I meet a problem with the display.

    If I try to test the inverter like you suggested, I have no backlight. However, if I connect the DVI cable of the iMac screen to the Macmini, I have a very good display of the OSX windows just few seconds and then it disappears. It happens at startup and when I do a sleep/wake. I see before and after the wake/sleep, a little bit the screen from the macmini but it is very dark and impossible to use.

    Maybe I break the inverter. Could it possible following your experience?

    Here are some details about my montage:
    I saw by myself that it is possible to use the power supply of the imac, as you saw by yourself it has already the 12V. For my test, I connect the power supply on the original motherboard and use the molex to get the 12V, 5V and the ground. I have also a down converter from 12V to 5V but it will be for later (I tried also with it and I had the same problem). I switch on and off the power supply thanks to start button of the motherboard and a switch on the AC plug too for security.

    Then I have connected from the molex the 5V to the red cable on the inverter, the 12V on the blue one, the black to the inverter ground, the 5V + 1Kohms on the inverter green cable and let purple and orange as a floating cable. I checked with a multimeter if the voltage is ok. But in this case I have no backlight.

    Then, I did the DVI connection to see if the display does something when connected. I have the VEDID 5V (pin 14 of the DVI) to red/pink cable of the LCD grey cable (before the 1Kohm), the VEDID connected to the 16 DVI pin via a 1Kohm. I removed the 5V of the power supply and connect the red alligator to the VEDID (before the 1kohm).
    When I do so, the display reacts few seconds after wake/sleep changement.

    I tried also to disconnect and reconnect the green inverter with the green + 1Kohm cable, after a wake/sleep changes, I have a good display for few seconds. The Voltage on the green cable of the inverter (after the power supply and the 1Kohm) is 4.6V when the display is black and 4.7V when the display show something.

    I am wondering if I have a problem with the inverter or a bad connection or too much/less current or voltage somewhere. Do you have any idea please?

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    1. Thank you for the offer, but I would not feel comfortable accepting donations for something I love working on and take so much personal satisfaction from. It seems that your inverter does not sustain the backlights even during the test phase. So, a couple questions?

      Are you "sharing" resistors? Make sure it's one resistor across one connection. also, change your resistors and make sure they are rated at least for 1/2 watt. A bad resistor can sabotage any project.

      Did you open up the the top of the computer? The LCD housing? The backlights tend to ground out very easily. If you have it open, disconnect one of the backlights and try it, then the other, if one of the backlights work you are grounding it out. Close up the monitor housing, ensuring nothing is exposed. Next I'd hook it up in test mode and try connecting and disconnecting the red wire.

      But the most likely scenario is this: it's unlikely (though not impossible) that the inverter is damaged, as it seems to turn on, but then gets turned off. If you have not opened the LCD housing, and your resistors are good, I would not use the molex from the PSU the way you have it arranged. As the molex's 12V rail emerges not directly from the PSU but from the motherboard (unusual). I suspect the motherboard would limit the current that this line has available and shuts down when you draw too much. The amperage involved in ccfl monitor backlights and power for the lcd are going to exceed that used for a hdd and DVD rom. Apple intended this to be only used in this purpose, unlike the power coming directly from a PSU. The 5V you may be able to get away with, but I assume you are also using this to power the LCD itself. If that's the case I'm not positive.

      Easiest way to test is to use a different PSU, if you have one. Grab an ATX PSU and jump it thn hook your molex up to this molex. Your backlights should turn on. Likewise an AC to molex adapter would work. If you wish to keep the same setup and don't have the above materials, I'd do the following: splice into one of the 12V lines coming from the PSU and going to the motherboard. You could either cut the shielding off with an Xacto knife (least invasive) or simply cut a wire. Maybe the easiest thing to do would be to cut 2 yellows and 2 blacks from the PSU. Strip both yellows and blacks. Take one yellow from the PSU and wrap it around the 2 yellow ends from the cut wires that lead to the motherboard. Thus, one yellow from the PSU now supplies 2 motherboard 12V rails. Do the same for the blacks/grounds. Use electrical tape and do not solder yet. (In case you need to undo it). You should have 1 unused black and yellow from the PSU. cut the yellow and its black/ground that go from the motherboard to the molex connector. Connect the PSUs yellow/black to the Molex's yellow/black and retest. Thus you should have a molex with the 12V rail and ground coming directly from the PSU and the 5V rail and ground from the original iMac motherboard. If any problems I'd use the downconverter as well, though I think you'll be ok. You should now have an image and backlights. Good luck and let me know. JB

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    2. Hi again, I followed your instruction help and the native PSU do not allow me to make the display correctly works. I had a display but completely unstable, the picture flickers and then comes completely white if I let it too long.
      Finally I get a pico PSU like as you explained to get a better result and finally it works with it.
      But something is very important to note. If I put the green cable on the 5V and the LCD yellow/orange/purple cable between the 5V and the resistor of the green cable, the picture flickers too. I used the dimmed cable of the inverter (purple) between the green cable of the inverter and the resistor, in this case the picture was really good stable but dimmed !!! So I supposed there is too much current which goes to the green and too few which goes to the yellow/orange/purple LCD cable.
      So it' s important to correctly cable the 5V of the LCD yellow/orange/purple directly on the 5V of the PSU and the Green cable of the inverter with the resistor on the Yellow/orange/purple LCD cable otherwise in my case it's unstable.

      Good to know for the other people, the 17" display of the flat iMac G4/G5 and its inverter with the iMac G4 Lamp. The housing is compatible. I say that because I 'burned' a display (too high voltage) and I replace it with the one of an iMac G4/G5. The inverter cable is not exactly the same but you could cut the cable and solder it. Just follow the same cable order of the original one.

      I am still working on my project to integrate with the macmini I will keep you inform.

      Thanks

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  79. Thank you very very much for your reply.
    It's hard now in Europe to find the inverter so I hope by following your advises I could find what's wrong. I will post my discovers and results to share my mod too.
    It's a really cool project, hard to do with the new imac models ;-)
    Best regards

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  80. Hey JBerg,

    I recently got an 800Mhz display working as an external monitor. The screen looks great, but there's a small problem--when my 13" Macbook Pro is connected to the display, it starts to "lag". I use quotation marks because I can move the mouse cursor around without any trouble. Everything else seems to have a slow refresh rate. What's more is that when I go into mission control, the computer freezes--that is, I can still move the mouse around, but everything else is frozen and I can't click anything.

    It seems to me like it's a problem with the computer, not the display. I've used other external displays without any problem. Anyway, I'd like to know if you have had similar problems, or if you have any insight into what's going on. Thanks for all your help!

    Caleb

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  81. Would this be any help in converting the screen formats?
    http://www.getmis.com/catalog/single-board-computers-slot-sbcs-embedded-boards-modules-/slot-based-single-board-computers-sbcs-/accessories-for-single-board-computers-sbcs-/p_db-v8298.html

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    1. Not really. This is just converting DVI to a different smaller pin layout to fit on a small board. It could theoretically make soldering easier, but I can't see it being of much more benifit than the DVI Connector

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  82. Hi JBerg,

    Great job on describing the steps.

    I have a working iMac not in use. I want to use its LCD as external monitor of my MacBook Pro. Since the iMac still works so I did not do the power supply and inverter portions in your guide, only rewired the the black and grey LCD cables. I took out all pins from the LCD connector except 19, 20, 21, 22, 23, and 24.(3.3V and grounds). I plugged the connector back to its place. I inserted all other pins into the DVI connector. In doing so I was hoping the LCD would get power from the original connector. When I connected MacBook Pro's miniDisplay Port with an adapter/DVI-cabble to iMac, (From MacBook Pro side I know it detected the connect to an external monitor.) then turned on the power of iMac, the screen is totally dark. I could hear the noise of the hard drive and fan. What could I be missing?

    Regards,

    Longwu Wu

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  83. Hi JBerg,

    On the inverter cable, I opened up orange and purple, freed green and connected it vis a 1 k resistor to 5V. The I got lights on the screen.

    Then I connected the power lines of LCD grey cable to native 5V. Cool, it worked all fine.

    Thanks for your great guides.

    Longwu Wu

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    1. Hi Guys I have a working Imac which I would love to turn intel but have limited funds. So my question is as above if the original hardware is in place and powered up would it not be possible to divert the video signal out to DVI for use with a smart phone (HTC one x)then carry on using the existing hardware with ubuntu server as a NAS drive/headless server ??

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    2. Sure I suppose its possible to add some kind of switch to allow for 2 video signals input. But, I have to warn you that it would be extremely challenging from a technical standpoint. You'd have to splice into all the TMDS cables that leave the motherboard, these wires are iny and chances are you'd end up damaging the cables. You may want to see if there is a software solution such as screen recycler

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  84. Hello JBerg

    I have a problem.
    I conected Inverter to 5V, it works great. When i conected a Gray cable i plug it by mistake to +12 V. I saw this : http://2.bp.blogspot.com/-vKAtNNssNKg/TuQyA6lBnVI/AAAAAAAABKM/Y7dicWq3MJQ/s1600/ConnectDemo.png There is 12V. But in the movie you said to connect it to 5 V. Probablly i burn somethn.

    Is There any way to fix it?

    Now i got lines on the screen.


    Sorry for my English. I hope you are able to understand that.

    Thanks You Kamil.

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    1. The diagram you are referencing is for the 20" not the 17". I do not know if something was damaged permanently, but it is possible. Trying a different LCD panel is the only way to know for sure.

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  85. Thanks for this tutorial. I recently got hold of a 15" iMac with a dead motherboard. I've now got a working monitor and next I will be maknig it into a Hackintosh following your NUC tutorial. I did make some substitions. For the DVI connector I used a 74320-3000. This is a DVI-I straight connector instead of the DVI-D right angle connector you used, but had the same pin sizes. I just ignored the extra analog pins on the connector. I also didn't have any 1k resistors so I used 2.2K which seems to work fine. Thanks again, Greg.

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    1. Greg how did you end up with the wires connected ? i do also have a 15 inch but can not get the backlights to work, could you help please

      Thx

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  86. Hi. Thank you so much for the tutorial. I got everything to work on 17" iMac 1/1.25ghz (using option 1 for the last bit) except that I get static background (bluish?) after a while. It's totally fine for the first few seconds but it get's progressively worse. Any idea?

    I have my power supply in the shell with the the DVI and I haven't insulated the small DVI connections. Could that cause things to go wrong? I was planning on insulating them all and maybe make a faraday cage and take the powersupply out of the shell.

    I would be grateful for your help.

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  87. This comment has been removed by the author.

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    1. This comment has been removed by the author.

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    2. Sorry, I wish I could be more helpful with the 15". I myself have never done it, I will take a look and let you know what I think though

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    3. This comment has been removed by the author.

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  88. On my 17 inch setup. I got the backlight working great, but when I setup the dvi pins, my power supply just gets extremely hot and you can smell burning inside of it, any ideas? Am I shorting something obvious? Here's a link to pictures of my current configuration.

    https://drive.google.com/folderview?id=0B3TRjE_fMVELSHhBZk1XRTlUWkU&usp=sharing

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  89. This happens when you cross-wire some things:

    https://picasaweb.google.com/109445931341543997778/IMac

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  90. how can I tell which three are powers from the gray cable? My 17" gray cable doesn`t have the same color as demonstration. weird. any ideas to check?

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  91. Hi, My 17" iMac G4`s gray cable doesn`t have the same color as the demonstration shows. what can I do? how can I tell which three are the power cables?
    https://lh5.googleusercontent.com/-ryhHkKKH6w0/Ubfb66TWpHI/AAAAAAAAABA/bV9FN2Qeqx0/w1075-h806-no/IMG_1508.JPG

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  92. Dear JBerg,
    I`m stuck and confusing. I Purchased another Neck of iMac G4 17", I followed your video step by step. However, When I tried to hook up the three Blue, Yellow Orange cables from Gray cable, It was like very hot and some tiny smokes came out.as the picture shows. Did I do something wrong about that? Can you fixed my problem? thanks and wait for your answer.
    https://lh6.googleusercontent.com/-nV2UgR7FS1I/Uc4wC0W0z-I/AAAAAAAAAC0/n7huLVSL5f0/w1075-h806-no/IMG_1835%255B1%255D.JPG

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    1. PS: I was trying to hook up those three cables to the red 5V molex cable as the pic shows.I couldn`t because it would burned.

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  93. This comment has been removed by the author.

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  94. AMAZING GUIDE!!!!! THANKSSSS!
    https://docs.google.com/file/d/0B4NGZGnUdtweQlZwejZ6cmZPZHM/edit?usp=sharing

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  95. hey fantastic job ,superb illustration not sure if my question went through , id like to keep my imac g4 base and go with a macmini mod with a benq24inch screen ,i havent seen how you cut out the hole on the back of the cinema displays to use the imac arm could you please describe/ and perhaps tell me if a benq monitor is functional as they are very lightand i see they are mac compatible ,just trying to figure out if i can mount it?

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