GUIDES and TUTORIALS

Sorry about the delay but...

After completing my latest mod, I promised a guide.  Due to personal reasons, I have not had a chance to work on this.  As time goes by and it is less fresh in my mind, it becomes somewhat more difficult to compile.  While all the information to do this mod is within this blog, it is not very well organized.  The Monitor to DVI instructions are contained within the 20" Sandy Bridge Guide.  While I talk about the native power source in this tutorial, I use a PICO power supply in this actual mod.  The native PSU is really discussed in a different post.  Likewise, wiring up the new NUC board is in a different post altogether.

I had initially constructed this site to be a "Tech Journal/Diary" where the most recent updates would be chronologically first and older entries could contain outdated or incorrect information.  As I became more involved in the iMac G4 project, this site became more of a guide/tutorial site.  While this isn't a bad thing, its just not exactly how it was designed to be.

As I've been putting together the tutorial for the 20" Ivy Bridge NUC Mod (in the form of audio over pictures), I've realized that this may be the opportunity for a "redesign".  I would like to keep this site as my tech journal site.  Even the failed mods and the process behind them is something I would like to "preserve".  I have secured "imacmods.com" and I am hoping to eventually link between these two sites for a more cohesive and straight forward experience.  Someone wanting to know how to connect the native PSU can click on it and either go to a written tutorial, video guide, or original dremel junkie post.

It is certainly not lost on me how confusing it is to google "iMac G4 Update" and think you've found the answer only to find several posts detailing somewhat related (but not the same mod).  Also, from my end, I have step by step photographed, documented, and wired up two different 17" necks (one on video) and a 20", and am now going to repeat it again for the 20".  This will allow me to have a "modular" approach where 'for instance' STEP B: Conversion to DVI remains the same regardless of which computer you use in the base.

I would greatly appreciate any advice from those more skilled than me at web site creation.  I would like it to be simple and easy to follow, but am a novice at this.  Please let me know if you have any suggestions.

The 20" NUC Tutorial

I want to assure you that this will not interfere with the 20" NUC tutorial.  The biggest hold up has been the fact that I am not 100% happy with the amount of pictures and detail that I captured.  My goal was to complete the mod and I was not as thorough with photographing and documenting the steps along the way.  Although I do not have a problem opening up my mod.  There is no doubt that I will have to do a decent amount of disassembly to get the pictures I would like.  If I am going to disassemble my mod, I would love to upgrade it in the process if possible.  Luckily, it does appear upgrades are not far off courtesy of Intel and Gigabyte:

From Gigabyte - The Brix:

Courtesy of Computerbase.de

Courtesy of Computerbase.de

This NUC based system is smaller, lighter, has more I/O options and will have i5 and i7 options.  While initially Ivy Bridge based, Haswell is likely not far behind.

And Intel:

Rend Lake will be i5 and USB 3.0 capable based of Ivy Bridge Architecture.

In retrospect the use of Thunderbolt was a waste on the initial NUC.  Initially I thought it would be "future proofing", but its been months later and the only intriguing peripheral is Belkin's (finally being released) $300 Thunderbolt dock.  Of course, its the USB 3.0 that makes this dock interesting.

Thus, this NUC should be far more versatile (at least I hope).

I am unsure of the variation in the "Horse Canyon" Core i5, it doesn't appear to use a Haswell Chip, though I can not be sure.

"Skull Canyon" is the Core i7 Variant, and the one for which I am most excited.

Of course, updates are always going to happen, and while these are only incremental upgrades, I have been looking for an opportunity to add USB 3.0 in particular (and get rid of the thunderbolt).  As these seem like they are "around the corner", I am asking for patience in terms of the guide.  Replacing the board is not difficult, but it would make more sense to only disassemble and reassemble this mod once.

So please stay tuned and hopefully the tutorial will be done shortly, with an even more powerful NUC serving as the computer.

EDID and HDCP

Some of you may have noticed an"incompatibility" with certain sources.  Sometimes this is due to playing digital protected content "HDCP" or even using certain motherboards.  For myself, the EPI-QS77 and I am told the Raspberry Pi as well, seem to cause incompatibility issues.  In some cases, changing from DVI to HDMI and back can remedy the problem, other times, artifacts persist in the monitor.  My guess is that some boards may have an incompatibility with the "EDID", the identifier of this LCD.  While there is no direct way around this, there is an "indirect way".

The White Polycarbonite Family

As I have mentioned before, prior to figuring out direct wiring of the existing LCD, I had found a work around.  This "work around" is used in the iMac G4 (pictured above) and although its just serving as a monitor (with a modded iMac G5), I have now been using it daily for over 2 years without any problems whatsoever.  This work around keeps the native inverter and can keep the LCD or use an LCD from an aluminum Apple Cinema Display or iMac G5.  The most important thing is that this uses the controller board from an apple cinema display.  While this does involve opening and rewiring the neck, it does give the LCD a true EDID and HDCP compatibility.  There are certain other advantages as well, but it is more technically challenging and will require some parts from a cinema display.

I mention this only to gauge interest.  Are there people who have experienced this problem? Are people interested in this particular method?

Thank you all again for your patience and thank you for taking the time to read this.

Afterthoughts and Future Plans

20" iMac G4 and 20" iMac G5 (Apple Cinema Display LCD Controller Hack)
Connected  to External Mac Mini

Genuine 20" iMac G4 All-In-One Sandy Bridge Hackintosh

Above you see my two favorite 20" mods.  The one on top uses an LCD controller from an Apple Cinema Display for both the iMac G4 (though the iMac G4 uses its native inverter) and the iMac G5.  These are connected to an external Mac Mini.  Although somewhat more complex, the great thing about this method is its stability.  It is really an apple cinema display in the form of an iMac G4 and G5.  The extra room in the in the iMacs is not put to waste.  The iMac G4 houses a USB optical drive (replacing the missing one on the Mac Mini.  The iMac G5's iSight and Mic are converted to USB.  This has become one of my most frequently used computers.

The second picture is my latest All-In-One Sandy Bridge Hackinosh using an ECX board to run Mac OS Lion.  This is very much native and did not require any alteration to the neck or lcd.  The computer, DVD burner, SSD (running lion) and onboard Compact Flash (running Windows 8 Developer Preview) are all internal.  This was a tremendous amount of fun and will make a great all-in-one computer.

Obviously both these methods are viable and both have their advantages.  From the outside, they are indistinguishable from each other or a native iMac G4.  Of course, which ever method you use for the LCD is independent of what you connect it to.

iMac neck connected to Apple Cinema Display

My slightly older 3rd method, used the actual housing from an apple cinema display.  The few extra millimeters this gave allowed the use of the cinema displays inverter (I had previously not been able to get the 20" iMac's native inverter to work).  This method also allowed for the addition of a 20" touch screen.  However, I have retired this mod for a couple reasons.  First, while I thought this was an acceptable work around at the time, I much prefer the look of the true LCD housing.  Second, while the touch screen was great with the iMac's design, I did not love the only touch screen I was able to find in the now rare 20" 16:10 size.  This resistive touch screen was fairly accurate, but its surface was uncomfortable to touch and its glossy plastic surface detracted from the resolution of the LCD.  Third, as a resistive screen single touch was all it could do.

While I now have a functional upgraded replica, I still like the idea of adding additional functionality to the iMac G4 with a touch screen.  There are a couple options that are now available.  Some capacitive screens have become much more reasonably priced.  Although they were originally designed as single touch, new software may be able to make them function with gestures and at multitouch.  Another possibility is optical or IR touch.  Although the available optionals do not come in 20" 16:10, they possibly can be tweaked.

The downside is that the 20" capacitive screen will add too much weight and the optical touch will require extra room between the LCD and the bezel.  One thing that may make this possible is to use LED backlighting which would be much thinner.  A fellow modder JP7 has done a fe amazing mods of apple cinema displays using LED backlights.

In terms of the base, I have no use for either a desktop monitor or an all-in-one.  But, a larger screen for a notebook computer has always been something I have considered for the iMac G4.  Using either wired technology (A thunderbolt dock? - If they eventually come in at a reasonable price) or wireless technology (Wireless DVI and USB adapter?) is something I can definitely see being useful.

Wireless DVI - Courtesy of Amazon.com

After I use my current G4 and G5 spare parts, I will probably move on from this.  And I still have a Cube which has been sitting waiting to be modded.

Completed Mod - Mac Mini with iMac G4 and G5 dual monitors

Original Dual Monitors with Mac Mini

New Setup with iSight G5, Mac Mini, and iPad

While the core components are completely unchanged from my previous 20" iMac G4 mod, this represents the completion of the overall setup.  I would highly recommend this to anyone in search of a "weekend hobby" who shares my enthusiasm for this generation of apple products.  Most people seem to be interested in the 17" mod, but as someone who has used both, I would recommend putting the resources into the 20" mod, if you truly intend to use this as a main desktop computer.  (Obviously if you already have a 17" dead iMac G4, its a different story).

Personally, it has become difficult for me to use LCDs under 19" as I've become so accustomed to larger displays.  The 20" iMac is a sizable display as is, but several factors actually make the screen bigger than most 20" displays.  For one, the aspect ratio is 16:10 not 16:9, for 20" this makes a substantial difference (1680x1050 vs 1600x900) in the overall size and pixel density.  Plus, the nature of the iMac G4 itself allows you to pull the display much closer to you than an ordinary LCD would sit.  Even still, to be a workstation, I feel multiple monitors are invaluable.  I got fortunate in "spare parts" that I was able to put the iMac G5 (native LCD, Apple Cinema Display's controller, inverter, and power source) together very quickly.  However, there are multiple ways to "resurrect" an iMac G5 as an external monitor depending on available parts.  The effect of having both together is great.  The iMac G5 is also quite ergonomic, in both its sliding and tilting.

While an All-In-One was the ultimate goal, by the time I figured out how to "modernize" the iMac with a Core 2 Duo Processor, Core 2 Duos were obsolete. With the mac mini also growing in length and depth, an all-in-one would need to be a hackintosh.  While the discussion regarding the price point of the mac mini is justified (depending on how you value aesthetics, form factor, and low power consumption), you can not call this generation underpowered.  I have been quite impressed, unless you are a gamer, there is not much you can't do with this machine.  (Im using the 2.7Ghz Dual Core i7 with discrete graphics.) For those waiting for the "X-Mac" this really might be it.

I originally concealed this in the inner part of the desk, but the I bought a great under desk mount with 4 front facing powered USB ports.

As I've mentioned the loss of the optical drive even as an option was unfortunate.  While both the G4 and G5 enclosures lend themselves to addition of an optical drive, its on the G4 where the drive actually contributes to the design.  While initially I was hoping to use bluray - Lion would not recognize the drive.  I ended up using an external DVD drive which I opened up and modified.

This is actually DC powered, so I used a power source from a broken internal drive enclosure.  I use the original iMac G4's AC plug, but split it, with one going to the cinema displays power brick and one going to the drive.  Thus, only one AC plug and no external power brick is required.

Rear Ports (USB Out, Drive Switch, AC Power)

The rear panel contains the original 3 pronged receptacle for AC power, an on/off switch for the drive, a USB out, the outgoing USB cable and HDMI cable.  The USB cable belongs to the cinema displays controller which then supplies 2 ports.  One is taken up by the drive internally, the other is on the back (hooked up to the camera here).  So, by having the drive plugged in, you essentially replace the used USB port.

Drive open

There is a quirk with the DVD drive.  When there is no media in the drive, the keyboard eject shortcuts do not work and you can not access the front button on the drive.  To eject the drive you have to open disk utility, click on the drive and press open.  Now by putting Disk Utility in the dock, opening the drive takes only 3 clicks, however, this is somewhat of a nuisance.  When media is in the drive this does not seem to be a problem.


SOLVED - thanks to fellow modder and iMac enthusiast Jean Luc, I now have an eject icon in the upper right corner, that allows me to easily eject and close the drive in the G4's dome.

This works flawlessly.  It eliminates a flaw of the mini and gives purpose to the base of the iMac G4.

Besides cleaning up a few of the rear ports, this iMac G4 mod is complete and perfect in this setup.  This is largely the same mod as before without the all in one.

Side/Rear iMac G5 (1st Generation) Mod

The iMac G5 chassis leaves plenty of room for further modification.  It is designed for speakers and its own drive.  Because I have an optical drive in the G4 and use the apple pro speakers, these are likely to be superfluous.  As of right now the Cinema Displays cable goes out where the power cable exited.  So the power brick is outside.  I may internalize this.  While I do like the ability to physically move the camera, I may consider obtaining an isight G5 and seeing if I can get an isight camera and convert it to USB.


UPDATED - with advise from Jean Luc and research I have realized that there is a considerable difference between the original iMac G5 (1st Generation)and the iSight iMac G5 (3rd Generation - much thinner, and with iSight camera/mic).  I am going to attempt to transfer the contents from this G5 to an empty chassis from an iSight G5.  I believe this will likely fit this mod better.  As I have stated much of the iMac G5's shell is currently wasted space, having a smaller, sleeker chassis would likely look better and save some desk space.  Although much tighter, the only contents that will need to fit are the Cinema Display's LCD controller and inverter .  In addition, as Jean Luc explains in the comments below, the iSight is simply a USB device.  With addition of either a USB adapter for the microphone, I can connect these to the Apple Cinema Display's USB ports.  As this leaves only 2 Firewire 400 ports, I would likely either hold off on adding the rear ports to see if my "thunderbolt dock" idea becomes feasible, or use a firewire to usb dock to add USB ports to the rear of the iMac G5.  The RAM access panel at the bottom may also let me bring back the Cinema Displays hardware touch power and brightness controls to the bottom of the display.

FURTHER UPDATED - I have indeed used JLs advise and the chassis of the iSight G5 complete with original microphone and iSight Camera.  Please see this post on the iMac G5 iSight for details.

At the very least I'm likely to add the Cinema Display's Firewire 400 and USB ports.  As I mentioned earlier, this monitor is hooked up using a mini display port via the thunderbolt port, I'd love to utilize this fact to make this a "dock".  Exactly as apple has done with its new Thunderbolt displays.  Thus, with one plug I could not only get the image to the G5s LCD but "transfer" the mac minis ports to the easily accessible rear panel of the G5.  This would allow for significant convenience.  I'm hoping such a dock may eventually become available or perhaps it could be taken from a broken thunderbolt display in the next year or so.

In general this is even beyond the setup that I envisioned as a best case scenario when I began this project.

Suggestions are appreciated.  And if there is interest I'd be happy to provide technical details.  Thank you for reading!

Optical Drives, Mac Minis, and Thunderbolt

Courtesy of apple.com

So the final part of my setup is "the actual computer".  I decided to go with the higher end non-server model.  I would have gone with the server for its quad core i7, but discrete graphics is quite important to me.  I have had some so-so experiences with onboard intel graphics in the past.  In terms of upgrades - I very much wanted a SSD, but for $600, it was not going to happen.  I have spoken to people who have changed or added drives to last years mini (same design) and while not simple it is doable.  So I went with the base 5400rpm 500GB drive knowing that eventually I'll likely add another drive or swap this out entirely.  I did decide to invest in the 2.7Ghz dual core i7 processor as this is something I won't be able to replace later and at $100 the cost wasn't ridiculous.

There was one "surprise" for me, I was not expecting the demise of the optical drive.  While this does cause me to alter my design, it really is not a big deal for me.  That said, I am somewhat disappointed in the decision.  The reason I say that is because it decreases the versatility of the machine.  Plenty of people viewed this as an ideal and elegant HTPC, many of those people have DVD collections, instead of an iTunes movie library.  For the Macbook Air - the initial decision to loose the optical drive allowed the chassis to become even thinner.  In the case of the mac mini there is an empty bay.  The design hasn't gotten smaller and unless you have two storage drives there is simply empty space.  Even if a drive wasn't included in the base model, an option for a Build to Order one would have been nice.  Optical media may not be the future but for many people it is the present and as small as it is, the mini is still a desktop computer.  Obviously, Apple can do what they want and as a huge media digital distributor they have a vested interest in seeing optical media disappear as soon as possible.  But, I thought they could have waited another generation as the people I know who waited for this machine as a living room computer have not decided to go digital, but have instead gone in a different direction.

This does open up some design potential for my setup which uses a converted iMac G4 and iMac G5:

While my initial design included a bluray drive in the base, I took it out as I thought it was redundant with the mini on the desk.  An internal drive was less complicated when there was a computer in base.  As this attached simply through an SATA + PWR connector to the motherboard.  While SATA to USB + Power brick adapters are available, I would like to keep the design as simple as possible.  Meaning I would prefer only one AC plug, no external power bricks and as few cables going between the mini and and the iMac G4 chassis as possible.

For there to be only "1 plug" I obviously have to split power off somewhere.  I can do this on the "AC side" before the power brick or on the "DC side" after the power brick.  I have an old 5.25" external drive enclosure that I have no further use for.  This includes a small power supply and onboard SATA to USB.

With some internal rearrangement I should be able to fit both the power supply as well as the drive.  Currently all that is in the base is the Cinema Displays LCD controller and Power Brick.  I am hoping to keep the power supplies at the top of the dome.  The drive in the middle and the controller on the underside of the drive.  Leaving the very bottom for some wire management.

Using the Cinema Display's on-board USB ports will allow me to connect the drive and replace the "used" USB port with one that will be on the back of the iMac G4s base.  In addition I will add either the rocker switch or a push button on/off to the back of the iMac G4 for the drive.  I do have the option of Firewire 400 ports but will probably not hook these up.  Although there is not currently any reliable support for it, I do have a full side 5.25" tray loading bluray drive which has already been modified to fit in the iMac, so I will probably be using this.

Courtesy of CNET

Another option is to use the iMac G5 or both.

PicoPSU by Mini-box.com

Of course, as I have previously noted, I have plenty of room in the iMac G5's chassis.  The way I felt this looked the best was to mimic the original look, whereby one cable comes out the back.  So the Cinema Display's Cable comes out the hole n the back, which I will eventually surround with white rubber to make it look as clean as possible.  As a result, the power brick is external.  To use an internal slim slot loading I need an SATA power source (12V), but the power coming in via the Cinema Display is DC at 24V.  In order to siphon off power I need a DC to DC voltage regulator or power supply.  I chose a picoPSU which can use 24V input.  I chose this because it was cheap, small, gives me lots of options, and I am familiar with it.

Using this and a SATA to USB I can again use the onboard USB slots of the cinema display.  And as I am already connecting the Cinema Displays cable to the computer, I may hook up the firewire 400 ports and connect them to the back of the monitor where they were designed to hook up to the iMac G5.

Back Panel Thunderbolt - Courtesy Apple.com

In my opinion one of the most interesting products Apple just launched was its new Thunderbolt display.  The idea that one cable (externally no different than the display cable) can turn the monitor into a "dock" is brilliant.  What would be ideal for my setup would be if they ever sold a separate "Thunderbolt dock".  A Thunderbolt cabe at one end with a mini display port, USB, firewire, ethernet, thunderbolt out (for daisy chaining) etc at the other end.  This would allow all sorts of devices/accessories to be stored in the iMac G4/G5 housing.  An example may be using Macbook Air with onboard Intel HD3000 graphics hooked up to a modified iMac G4 or G5.  But inside of the iMac enclosure is not just an LCD but a powerful PCI-Express graphics card hooked up via thunderbolt (I know it wouldn't be fully x16 - but it would still be very capable) as well as a 3TB HD array and Bluray drive that all becomes accessible as you hook one cable up to your laptop.  It really may make these mods more than just monitors.

20" LCDs, Signaling, Inverters, and Pinouts

After getting some questions, I realized that it isn't very clear on my blog what makes the 20" iMac G4 different from the 15 and 17" models.  Simply put the difference is the inverter and powering the backlights on a 20"LCD.

Monitor Components

I) Intro - LCDs

To explain just some basics about LCDs: (I am no expert so please forgive me if things are slightly wrong or grossly oversimplified).

Most monitors (that connect to an AC power source) contain the LCD itself and then two boards. (See image on the right)

1) Top of the image is the LCD controller board.  This is where DVI/VGA plugs in and gets converted to a signal type, usually LVDS.  The controller also connects to a power button and some other control buttons.  Thus, the board can adjust aspects of the image such as brightness, contrast, position etc.

2) Bottom of the image is the Power Source/Inverter.  AC Plugs in here and powers the backlights (connectors at the bottom).  The backlights traditionally CCFL lights (now more LED) allow you to see the displayed image.  The AC is also converted to DC and supplies power to the LCD controller and via the LCD controller the LCD panel itself.

JAE connectors

II) Signaling Types

LVDS (Low Voltage Differential Signaling) along with power (usually 5 - 12V) and ground wires go from the controller to the LCD via a multi cable connector - usually a JAE connector.

Every Apple Product involving an LCD that I have worked on so far works somewhat differently.  This includes all the iMac G4's, the 20" iMac G5, and the 20" aluminum Apple Cinema Display.

The major difference is that the Type of signaling used is TMDS (Transition Minimized Differential Signaling).  While I do use the term "TMDS to DVI conversion" in my blog, this is actually a misnomer as there is no real conversion.  TMDS is the type of signal that DVI and HDMI cables use.  Nothing gets converted, its just that the wires get arranged in the right sequence and POWER is added.  Inside the LCD casing itself there is a Texas Instruments chip that allows the monitor to utilize the TMDS signal.  Therefore, ALL of the LCDs in the above computers can be connected directly to any TMDS signal - meaning any source that sends a signal over a DVI or HDMI cable.

Panel Names: (May not be complete) - All TMDS compliant

iMac G4 17" - LG LM171W02(A4)

iMac G4 20" - IDTech M201Z2-M01

iMac G5 20" - LG LM201W01(A5)(K1, K2, or K3)

Aluminum Apple Cinema Display 20" - LG LM201W01(A6)(K1)

III) LCD Controllers

Inside the Cinema Display

DVI going directly to LCD

Even though all the data goes directly to the panel, there are still LCD controllers.  In the case of the iMac G4 and G5, the controller is in the motherboard.  There is no conversion of signal, but power to the panel and brightness is controllable.  There is an LCD controller in the cinema display.  The actual TMDS data cables go directly to the LCD from the DVI cable.  The ACD's LCD controller does add the power to the display and changes brightness, connects to a power button, and is also a USB/Firewire hub.

Again, for all these panels, you can connect DVI or HDMI wires directly to the LCD's JAE wires.  As long as you also supply power for the panel (12V for the 20" panels and Grounds) as well as forgo hardware control of brightness - you will produce an image.  But, you will not be able to see the image without backlights.

IV) Inverters

Like any monitor with CCFL backlights you need to AC power.  The iMacs do not need a power source because the computer itself already has one.  DC voltage goes to an inverter that turns the DC voltage into high AC voltage (>1.5 Kilovolts) allowing the bulbs to turn on.  The Cinema Display actually works the same way.   The external powerbrick is the power source, taking AC and putting out 24V DC.  So even with a working image you need an inverter to turn on the backlights to see it.

For the 15" iMac G4 other modders were able to figure out what to feed the inverter to get it to turn on.  They used an ATX power source.  I determined the 17" iMac inverter pinouts because I had a working inverter, power source, and although it froze with booting - motherboard.  So because there was an image I was able to determine what voltages went to what inverter cables to turn the backlights on.  I then used an AC to molex adapter (Gives 12V, 5V, and Ground), approximated the voltages (I didn't have a 3.3V line), and turned on the backlights.

So here is the problem with the iMac G4 20".  First, no other inverter which can power the backlights that I have found is thin enough to fit in the case.  Trust me I've tried a lot - See this post for details.  So while there was only 12V, 5V (3.3V recommended but not needed) for the 15" and 17", the 20" was not so simple.  Remember all these voltages are easily available from any ATX power supply.  The 20" inverter needs a 24V power line.  In addition, while I can identify the power lines, grounds, on/off, and dimmer of the other inverters, there was an extra wire with the 20" that I'm not really sure what it does.  So, you need a power source capable of 24V, 12V (to power the LCD panel), and 3.3V - any old ATX power supply will not do.  The native iMac G4 20", G5 20" or 20" ACD all have power supplies that do have a 24V output.  That was original reason i was using the Apple Cinema Display in the first place - I did not have a working iMac G4 20" power supply.  What complicated things further was although I had a general idea, I could not determine voltages from a multimeter, thus it was guess and check.  Unfortunately, when I burned out an inverter I realized that this method wasn't going to work.

V) Solutions

Using the controller of the Apple Cinema Display solves the problem.  The controller is really a series of resistors that takes the 24V DC and splits it up into the voltages needed to power the panel and the inverter.  Plus it adds on/off, brightness control, and a USB/Firewire hub.  But, this is essentially the same as the "TMDS to DVI conversion for the 20" that I posted here, as far as the TMDS data is concerned.  Using this controller simplifies and stabilizes the system very well.  This is obviously not the most cost efficient method.  However, buying a working 24V power source can be expensive as well, so if you need to buy one anyway, I would recommend going for a cinema display with a broken screen.

But for those of you that either have a working iMac G4 20" power supply or some other 24V source there is obviously a way to get it working.  Now that I actually have a set up that works, some may wonder if I can now determine what DC voltages are needed to "activate" the native inverter.  The answer is yes and I have already done so - I will post the inverter voltages in my next post.  Two things about this are unusual. For one, there is a yellow wire with an extremely low voltage, I believe its part of the on/off mechanism or backlight control.  I am not sure if there is something else that I am missing with this wire.  Second, I have given just the voltages, you will need a fairly high resistor for the yellow wire even if you connect it to the 3.3V, but I don't know the current of the power supply to calculate it.

Finishing Touches and Ports

Although, I was disappointed by the limitation in operating system - I'm still excited that this is a true 20" all-in-one complete with blu-ray drive.  So, I want to make it as professional as possible.  I took the base apart to better secure everything.  Here you can see the ECX board elevated and secured to the Blu-ray drive.  I am using the native drive caddy - but did have to dremel off the top part of it to make room for the board.

As the CPU fan fits right under the dome I elected not to add an additional case fan.  There is no hard drive or power source and this is a low power consumption board, but I may revisit this depending on my cpu temps.  I had also initially placed a wifi card at the top of the dome, but the reception was too poor, so I have removed this and will use an external usb card.

For ports, I have chosen to use mostly extenders.  I find wires easier to deal with than circuits.

To cement things into place modeling clay/epoxy works well.  There are multiple kinds, but the basic idea is to mix equal parts to two compounds which begin to harden when combined.

The first thing I secured was the power button, placing a small momentary switch right behind the native iMac G4's power button.

The Right sided ports were where the ethernet, modem, and audio jacks were for the native iMac G4.  I have replaced these with a ethernet splitter and the power led, hdd led.  In the picture below you do see an audio header, which I was originally going to use, however, the ECX board uses a pin layout that I was unfamiliar with.   So I held off audio out for now and incorporated the two led lights.

The left sided ports consisted of 2 fire wires, 3 USB and a display out.  I opened up the display port somewhat to allow another USB port.  Because I am worried about power constraints (I'm using a 60 watt power supply).  I wanted to make sure I used some powered USB slots.  Fortunately I have another power supply coming into the base in the form of the Apple Cinema Display.  The controller gives 2 USB outs.  So two from the mobo and 2 from the cinema display = 4 total.  The firewire ports i am leaving empty for now.  The cinema display does allow for 2 firewire connections and I could add a firewire PCI express at some point.  I was also thinking about cutting a hope between these and putting an HDMI extender for use as a second monitor when needed.

Now that I have the basic layout I apply the molding.  It usually takes a good 24 hourse to harden.  I will use the center for the two power supplies.  The DC for the motherboard will be a simple plug, but unfortunately because there is no female version of the cinema display power, I am likely going to have to simply "run the cable out the back".

 So I place the drive caddy with bluray and ECX and secure it as it was designed to be.  After the ports dry I will secure them to the bottom of the dome, secure the Apple cinema display's LCD controller to the bottom and close the base.

As always, questions and comments are welcomed.  But, this should be complete within the next few days.

Update - The Native Inverter and LCD Glass

First let me start off by saying that I did something very stupid despite me writing not to do this time and time again.  I soldered the DVI connector on without putting it through the hole in the dome.  So I had to cut and resolder and for those of you that have never seen the components of the black wire of the imac neck, I can tell you it as an absolute nightmare.  They are composed of 4 wires in which are 3 wires; a red (+), a green (-), and a ground.  The red and green wires have a small plastic coat surrounding a single wire that is the size of a hair. When I set up this initially I had the bottom pins on and was able to use a tiny dab of solder, having to resolder these tiny wires, wire to wire has caused signal problems.  Keep in mind even one failed connection will give you no image whatsoever, so a multimeter is very helpful.  But poor connections or poorly shielded connections will result in color distortion.

That said there is some very GOOD news.  The native LCD for the Apple cinema display (LM201W03) needs to be modified to fit and although it fits, I decided to try the native iMac G4's (IDTech 20.1") lcd glass and it also appeared to work (though until I have a perfect image I can not confirm this 100%).  So it is possible that the only thing you may need is the LCD controller board from the apple cinema display and the cable to get this mod to work as the native G4 inverter has been confirmed to work and the native LCD glass appears to work.  This would be quite helpful as you can use a broken cinema display with a cracked screen.

 To the right you see the mod to date.  The top monitor housing closes as easily as the original as it uses the native inverter and the native glass.  Because I wanted this mod to be as close to the original as possible - I actually purchased a new monitor housing and base cover from ebay as most of the broken used iMacs I have acquired tend to be yellowed or scratched.

You can see the monitor from the front, side and back.  To the right of that is the lcd controller and ECX motherboard.  The ECX boots from a compact flash card located on the underside of the board.

The ECX board is the size of a 3.5" drive.  My plan is to mount the ECX board on top of a blu ray drive in the native drive caddy.  (essentially taking the place of the native hard drive).  As the CPU fan will be sitting at the top of the dome, I will not need a fan, so I should be able to fit Wifi and Bluetooth at the top of the dome with the vent holes.  As I will not be using the native power supply I should have room around the ECX board to fit connectors.  The lcd controller board will replace the native iMac G4's motherboard at the bottom of the dome below the drive.  As its smaller than the native motherboard I'm hoping to have room to wire up some rear I/O ports.  The only downside is that this leaves no room from the power supplies for both the monitor and ECX board.  They would fit in the drive caddy and using a splitter a simple AC plug could be placed in the back, but then obviously there would be no drive.  I have thought about using the native iMac's power supply, but I really need the room and in a similar experiment I fried a different ECX board in the past.

So, I'm going to keep them external.  For one the power supplies are small and this is a desktop computer, it won't be moved that much.  Plus, I have always loved the drive and by using blu-ray it can be useful.  Also, its gonna be tight in there and there is really no cooling system in place - so keeping hot power sources external is probably for the best.

I do think the system is likely to be hackintoshable - the chipset has been hackintoshed before (this is the Quanmax KEEX-4030 ECX board for those interested).  The thing that I have never heard about is booting snow leopard from a compact flash card - a 2.5" or even 1.8" SSD may have to be shoehorned in somewhere if hackintosh is your goal.

Here is the system booting (again notice the small resolution during the boot that I previously discussed).

This is where the frustration set in - with windows booting.  While I previously had a pristine image, after the resolder, the colors are unfortunately off.  A multimeter revealed all intact connections but I was getting some week noise at the wrong pins - so I suspect some interference or crosstalk.  I'm going to remove all the solder joints for the black wires and try redoing them with fresh connections and extra shielding.

To do this mod, I actually used cables from the necks of different iMacs.  There are the black and grey cables that carry the DVI signal, however the apple cinema display has "extra wires".  Some of these probably aren't necessary, but some of them are.  As a result, I had to add an extra grey wire from a different iMac.  I replaced the native LED/Microphone cable with this wire.  The wiring is somewhat difficult to explain.  If I continue to have difficulty with the black wire of the native iMac, I will likely change it to a different wire.  Likely either the equivalent wires from the apple cinema display or another grey wire.  Both of these choices would be MUCH easier to work with.  Either way when I do finalize how I wire the neck, I will post specific instructions.

While I am quite proud of some of the previous mods - this mod is actually much simpler and besides having to push some wires through the neck, a lot less labor intensive than previous mods.  In addition, if it does turn out, as it seems, that either LCD panel can be used, combinations of discarded iMac G4's and apple cinema displays can be used.  I would NEVER tear apart a working iMac G4 and couldn't bring myself to tear open my mac mini to try to fit it in the base.  I even hated even using a working apple cinema display in my previous mod.  Its always great to re-purpose otherwise useless parts.  But whats great about this mod is that there are so many different ways, but this one feels the closest to the native 20" iMac G4 that I've come so far.

Keep in mind that the KEEX-4030 uses the same Socket P Penryn Core 2 Duo chip thats in the previous and current generations of minis.  This ECX board is no slouch.  That said, if there was a problem with it, I think this is the mod that I would open up a mac mini for and try to put it in the base.

I'm hoping to figure out the wiring, clean up the image and start putting the base together this weekend.  But, as always all comments and suggestions are appreciated, but please no comments about seeing windows on the iMac G4 - Its the only operating system I currently have on a compact flash card.  Also feel free to ask any questions.

A Genuine iMac G4 All-In-One

Although I thought the previous 20" iMac G4 / Apple Cinema Display came out very well and it has become my most frequently used desktop, there were compromises that I had to make.  The two biggest ones were externalizing the computer (abandoning the all-in-one concept) and using the external housing of the apple cinema display.  While I think it looks good, it still is not the classic 20" iMac G4.  While working on a different mod, I realized there are two things I overlooked while designing and building the previous mod that would allow a genuine 20" iMac G4 all-in-one with an updated intel processor.

I was working on a project which involved using some of my spare components with a broken shell of an iMac G5.  These were mostly unused pieces from my iMac G4 mod.  This predominantly included a LG LM201W03 monitor from an apple cinema display (although the G5 I believe uses the same panel with some variations).   And the ECX board which uses a P8700 Penryn Core 2 Duo processor (the current mac mini uses the P8600).

Comparison of native iMacs DVD/HD to size of Bluray with ECX board

As it is the size of a 3.5" drive and it has its own  Compact Flash slot to use as a SSD, I had hoped to slot this into the G4 in place of the existing hard drive and create an all-in-one that even kept the DVD drive. However, when it booted it would not display at the required 1680x1050 resolution of the cinema display.

I had thought that the ECX board simply could not output at the requited resolution.  The ECX board has a PCI express x 4 slot, I attempted to add  a PCI express x1 Ion graphics card, while this fixed the resolution problem, the ECX ples the graphics card no longer easily fit into the iMac G4's chassis.

I was wrong.  The ECX board can support the resolution, it seems to have a quirk with the cinema displaythat it detects it as multiple monitors one of which is a lower resolution.  When I manually adjusted the resolution in windows and turned off the "phantom display", the display became full size.

Although I have not minded having the external mini, this board gives essentially the same power as the newest mac mini plus it has 4GB of ram and uses compact flash for a SSD, if its "hackintoshable" - I do not know yet.

I still did not want to alter my old mod in any way that may damage it, nor did I want repeat the same cinema display hack.  I wanted to use the existing iMac G4's monitor housing.  This brings me to the second thing I had overlooked.

I decided to use the Apple Cinema Display enclosure because the iMac G4's monitor enclosure fits the lcd panel and its specially made super thin inverter and NOTHING else.  And I was never able to figure out how to use the native G4 inverter without the G4 motherboard itself.   For the first time I decided to compare the apple cinema display's inverter to the iMac G4's to see if there was any way the cinema display's inverter could fit within the G4's monitor housing.  Thats when I noticed the 8pin connectors were almost identical.

The iMac G4 only uses 7 of the 8pins, however when the one was not connected, it would not turn off immediately when the computer slept, so I will have to make sure I have one extra wire going through the neck to use all 8 pins of the inverter.  To my surprise when all 8 pins were connected it worked perfectly.  If there was any difference I was unable to see it.

Being able to use the native inverter meant that I could use the native iMac G4's monitor housing with the Apple Cinema Diaplay if I could find a place for one more board - the LCD controller board.  The controller board is very flat but is not flat enough to fit withing the housing.

Comparison of iMac G4 bottom with native motherboard vs. ACD LCD controller

Unlike the inverter whose high voltage cables should not be extended through the neck, there is no reason why the lcd controller can't be placed in the base and its cables extended to both the inverter and LCD panel.

As it is just as plat as the native motherboard which I will not be using it can fit at the very bottom of the dome.

The only true nuisance with this is that although both panels use TMDS signaling, the neck needs to be modified.  The existing Inverter wires can stay, but by placing the controller in the base, there are a total of 27 wires that need to extend up to the neck.  The black and grey wires combined have 22 wires.  Plus I needed one extra wire for the 8th inverter wire, making a total of 28 wires.  To add additional wires, I did take apart the neck and change the microphone, lcd wire to an additional grey iMac TMDS cable that I had from a different neck.  Once I had all the connectors soldered on I was able to put the inverter and lcd on one side of the neck and the lcd controller and ecx board on the other.

Unfortunately it does not look like I'll have room for both a power source and a DVD/Bluray.  I will be able to fit one or the other.  Right now I'm leaning towards keeping the drive and having a power brick external.  I want this mod to look as genuine as possible, as such I'm forgoing anytouchscreen option.

Powering it on revealed a clear image:

Now to internalize it into an iMac G4 20" shell to see if it will fit.  This is the most hopeful I've been for a genuine iMac G4 20" all-in-one with modernized hardware.

As always, feel free to ask any questions.