iMac G4 Ivy Bridge Hackintosh: Finishing Touches

Completed Mod

While the previous Sandy Bridge Mod worked fine, this board is simply a perfect fit.  It runs cooler, uses less power, keeps the optical drive, supports mountain lion, uses the native PSU (which not only ditches the external power brick, but it even provides 30 extra watts of power).  This is much more stable.  Only S3 sleep (S1 works fine) remains a problem.

A Great Fit

The two extra additions are the 12V to 19V upconverter, which powers the actual motherboard.

and the Wide Input PSU, which allows the peripherals (The optical drive and the Fan) to turn on only when the motherboard is on and activates the PSUs 24V line via its 5V switch.  Both these fit (although its tight) and work perfectly.

With the exception of some cosmetics, I have completed the back ports.  They include 4 USBs, though 1 is used by a small Bluetooth adapter, a 3.5mm audio jack, the native AC power plug, and a "fake" Firewire 400 plug.  Its fake because it isn't a true firewire cable, it is only connected to a 12V Molex/Ground, so it supplies only power.  This is for use with the Griffin ifire adapter which gets its power from firwire and its signal from a 3.5mm audio jack and has an apple minijack out for the apple pro speakers.  This is very much akin to the original apple pro speakers that came with the G4 Cube.  They used an external amp which plugged into a special "high voltage USB port".  So although the speakers are not directly plugged in like the original, with the iFire, no additional power source is needed.  I did not want to break open and try to internalize the iFire.  This would have wasted the valuable iFire and constrained this mod to only those speakers.  The iFire also allows lengthening of the speaker cable, which is far to short on the apple pro speakers.

Other small improvements include:
Using KeyMap4Macbook to allow the keyboard button to eject the SATA to USB drive.

Changing the Mac Mini Pic in Resources to the 20" iMac G4, so the iMac's pic displays in "About this Mac".

About this Mac

The Full View

I will do a video shortly and am hoping to combine old pictures and new pictures into a comprehensive guide for doing this, including parts list.

Almost all the shortcomings of my previous mod has been addressed.  I am really pleased with this and hope this is helpful to others interested in this mod.  Thanks for reading!

A Great Little Board

A Change of Heart

When I first ordered the Intel NUC, my purpose was to see if this form factor had promise for the future.  I also figured that this small board would be useful to test projects and perhaps even wind up as a little media center somewhere.  In truth, I did not expect to seriously consider this board for the iMac G4 project. After working with this board for a while, I have to admit, its pretty fantastic.  For one, the size is remarkable, especially when it is removed from the case. This makes even ECX boards look big.  Secondly, its dead simple, it uses EFI bios, requires only RAM, a half height WiFi mSATA, and a full size mSATA SSD.  The mSATA in particular makes the system even smaller.  There is no need for even a 2.5" drive and nearly all wires are eliminated in this fashion.

 

As opposed to the other boards, this board only contains a Core i3 processor and there is a paucity of USB ports (only 3), mSATAs (one half height, one full height), an HDMI connector, and either a Ethernet + extra HDMI or Thunderbolt. (Depending on which of the 2 models you choose).



A Look Inside

 Despite these negatives there are other advantages this board has.  The availability of 2 RAM slots for a max of 16GB.  Thunderbolt while (at this point) is expensive and has few compatible devices does leave open impressive possibilities including hubs, a second display, and even a pci express graphics card.  The size also leaves most of the base available as it fits between the native PSU right under the fan and allows you to keep the optical drive (though a USB connection would be needed as there are no regular SATA hookups).

The Software/A Mountain Lion Hackintosh

The only method I use is tonymac's retail Mountain Lion Unibeast/Multibeast install method.  While the other boards took a very long time to get right, this could not have been easier.  I did know in advance to change the graphics to 128MB and of course AHCI instead of IDE (for the SATA controller).  Except for these small changes, there is almost no way to go wrong.  I used the Easy Beast Install with the Mac Mini 6,1 definition.  Now the reason for this is that there isn't much to the board, while other motherboards are loaded with other chipsets for gigabit Ethernet, SATA controllers, Touchscreen controllers, other I/O controllers, and business related QM chipset features, this board is really only about the basics.  But, with hackintoshes, less is more.  Having to clear your CMOS after you mistakenly enable some feature is no fun.  Neither is having to reinstall the OS because you decide to try to get native audio to work one last try.  This makes it very time consuming when it comes time to upgrade your OS.

 

One note,  I have read HDMI audio does require a work around, but this obviously does not apply to this mod.  Without any other audio cable out, a USB audio card will be needed.  But, so far airplay seems to work flawlessly, and can make for a wireless alternative.  So, in short, if a modestly powerful Ivy Bridge Hackintosh is your goal for this mod, I would recommend these boards above the others.  Being the easiest to find and the most affordable also doesn't hurt.

 

About This Mac

 Some Technical Issues to Solve:

1) Ports: 3 USBs is simply not enough and for basic function more is needed.  Thunderbolt hubs are absurdly overpriced right now, but either a Thunderbolt to SATA and/or USB or a regular USB Hub will be needed.  One USB is needed for the 5V "backlight power on" signal.

2) Fan:  there is a directional fan, but due to the faraday cage, I would still like to add the case fan in some manner.  This may involve replacing the existing fan and situating it directly underneath the iMac's case fan, splicing the fan wire to power it.  Or, running both, using the PSU to drive the fan (though a manual control knob may then make sense).

3) Power switch: This is hard soldered to the board.  A bypass will need to be wired up and I am fairly sure this can be done in an easy to reverse way.

4) Audio: A USB audio solution is needed.  This is not a difficult thing to find, but I am considering an airplay or Bluetooth based solution.

5) Bluetooth: I have been unable to find a Wifi/Bluetooth combo half height card that will work so far, so I will have to go with a Bluetooth dongle.

6) The Optical Drive: Using this solution means using USB to SATA to connect to a drive, but it will still need to be powered.  May require 12V to 5V downconverter.

7) Power: Worst case Scenario would involve connecting AC to the small power brick that comes with the NUC, but this seems like a waste.  Unfortunately as this board needs 19V, either an upconverter or downconverter will be needed to go from either 12V or 24V.

Concluding Thoughts

Although I'm not certain, I am actually leaning towards this board,  If this was an i5, putting it on par with my previous system (with more RAM and better graphics) this would be a slamdunk.  Each EPIC or ECX board requires different connectors, drivers etc. As Intel is likely to continually upgrade this form factor, getting this right may "future proof" future designs.  I am likely to build this out and see what the final project looks like and how it functions.

 

I will certainly post detailed instructions and may do a video guide if there is enough interest.  Thanks again for reading!

 



Ivy Bridge Upgrades via Small Form Factor Boards

The Current SFF (Small Form Factor) Market and Trends:

As I mentioned in a previous post, I had suspended work on my iMac G4 20" upgrade until Small Form Factor Ivy Bridge Boards become available.  I have become somewhat of a small form factor enthusiast as a result of these projects and am excited by the accessibility of what previously were industrial only form factors as well as new specifically targeted enthusiast boards such as the Raspberry Pi, Android Compatible ARM boards, and Intel's NUC line.  I am pleased to report that I am in possession of one SFF Ivy Bridge Board and have another two ordered and en route.

As the size and power consumption of powerful processors and boards continue to decrease these mods will only continue to get easier, more diverse, more powerful, and less expensive.  The one "nuisance" of the recent computing era (at least for these projects) has been an unbalanced focus on shrinking things primarily by thickness.  The ultrabook and tablet markets have caused a "flattening" of components without as significant a change in the other dimensions.  Take the Mac Mini for example, the overall volume decreased as a result of a dramatic reduction in height, but this was in spite of an actual increase in the footprint (length x width).

Old on top, New on bottom
Courtesy of CNET

SFF Computing and iMac G4 Mods

A Tight Squeeze

As far as the iMac G4 mod (and many other mods/projects) are concerned this can actually complicate things.  For those not familiar with my approach to the iMac G4 is Mobos smaller = better.

To sum up, the original iMac was convection cooled were physical contact via heat pipes carried heat to the top of the dome where a fan blew out. Thus the very poorly ventilated case was designed to be cooled with room temperature air coming in through slits at the bottom of the dome and hot air being blown out through the top of the dome.  Any air cooled motherboard/cpu (by far the hottest and most important component) benefits from being as close to the top as possible because it decreases the distance the heated air has to travel before it reaches the case fan and ventilation and decreases the heat of the overall dome and the heat the components above the mono/cpu are subjected to.  Also, probably most important, placement at the bottom of the dome will unavoidably result in poor, obstructed ventilation.  Any other component, especially wiring, will have to go above the CPU and mobo.  As the dome tapers to the fan at its apex and the faraday (metal inside) cage makes most of the periphery of the dome difficult to use for components.  If all you want is a motherboard and cpu, it can be done with a large heatsink to the top of the dome and a low thermal output processor, but no other components could be added and wiring would still be difficult.

Using a small form factor board allowed me to use a Core i processor at the top of the dome and allowed the rest of the dome to be used for a pico PSU, a full 5.25" optical drive, and a 2.5" solid state HDD.  As the widest point base still barely fits a mini itx (and port blocking is a problem), so options have been limited.  I am fairly certain the the mac mini will eventually shrink in all directions and that it will be suitable for a G4 mod.  In addition, I am hopeful, new form factors of computing will emerge and we will see other alternatives to the ultrathin rectangles that dominate today.  But for now, this is what I am working with:

Current Ivy Bridge SFF Options:

I will be reviewing each of the options based on features, cost to performance ratio, size and workability with the iMac G4 mod, and "hackintoshability".  Therefore, expect this post to be a work in progress with periodic updates.  Again, I am focusing on high performance x86 architecture, but this is by no means a slight to alternatives such as low-power Nano/Pico x86 boards or increasingly popular ARM devices, this is simply a matter of personal preference.

Choice 0: Quanmaxx KEEX-6100 ECX board

KEEX-6100 with large heatsink

I am listing this as "Choice 0" because it is based on Sandy Bridge Architecture, but it has been overwhelming successful particularly as a hackintosh running OSX Lion.  It is available from Quanmaxx's USA store and is even available in a wide temperature variant.  Here it is seen with an extra large heatsink I adapted when I upgraded this to a Core-i7 Quad.

Choice 1: Avalue's EPI-QM-77

Front View

Though this EPIC board is slightly larger, this board is"thinner" as a result of more room for ports on the edges, thus no need for the stacked ports seen on the ECX boards.  It remains a small form factor that easily fits the iMac G4 chassis.  It is available from Global American and I have it in my possession and just started working with it.

Back View

In terms of size, here are pictures of this board in the middle with a Core i Mini-itx on its left and the Quanmaxx (with regular heatsink) on the right.  The first picture shows overall dimensions,while the second shows thickness/height.

From Left to Right: Mini itx, EPIC, ECX

From Left to Right: Mini itx, EPIC, ECX

Choice 2: Aaeon's GENE-HM76 ECX

Also available as a more expensive QM77 (has extra corporate features, most apple mobile Ivy bridge processors are HM77 (very similar to HM76).

Courtesy of Aaeon

This is a true ECX board and identical in size to the Quanmaxx ECX.  I have purchased this board from NextWarehouse and it is en route.

Choice 3: Intel NUC: DC321BY QS77

Courtesy of Newegg

Although it only contains a Core i3, this is the one I am most excited about.  This is because of reasons outlined in my previous post.  This is the smallest Core i board that intel believes is possible.  This board is targeted at the mainstream and this model includes thunderbolt connectivity.  This comes with a "chassis" and is likely to see upgraded models at regular intervals in the future.  It is widely available from vendors including Newegg.  It has been ordered and I will continue to update as I learn more.

The "Next Unit of Computing" - A Small Form Factor for Mainstream Users?

Courtesy of PC World

Pictured above is an all in one kit which contains a new Intel sponsored form factor called the NUC or "Next Unit of Computing" which if rumors are to be believed will go on sale this fall.  This little box features an Ivy Bridge Core i3 Processor, including HD 4000 graphics.

At 4" x 4" (102 x 102mm), the motherboard contained within is even slightly smaller than the smaller side of ECX boards (105 x 146mm - yes the 3.5" board is not actually 3.5", but it is the same size as 3.5" drives, which are not 3.5" but have 3.5" platters inside them).  These boards are smaller than the semi-mainstream nano itx boards (120 x 120mm) and even give the ultra-tiny PicoITX (100 x 72mm) a run for its money.

The only information I know comes from these articles:

Engadget's Story on the NUC

PC World's Story on the NUC

The Top of the NUC
(Courtesy of PC World)

But, if this is to believed, this would be a huge boon for hobbyists, modders, and small form factor enthusiasts.  To summarize, Intel undertook a project to determine the smallest possible form factor that would be needed to support a full Ivy Bridge CPU + Expansion and came up with NUC.  I had actually  read about this in an article several months back, but moved on when I read that intel sees this being used in digital signage and kiosks.  I thought that this was just a slightly different form factor for industrial/embedded applications that I've talked about many times on this blog (ECX, EPIC, etc).  I do not know if this was intel's goal from the beginning or if the popularity of other small form factors such as the Raspberry Pi, VIA's pico itx boards or Zotac's Zbox caused a change of heart, but it appears this product is headed for the mainstream.

The Bottom of the NUC
(Courtesy of PC World)

What makes the NUC board so special?

Now functionally, as of right now, there is likely little difference between the end result of using one of the industrial boards I have previously mentioned or VIA's/Zotac's offerings, and this board, but there are some key differences that make this board 'special'?

1) MAINSTREAM

What mainstream means is availability to consumers via retail outlets.  This may not seem like a huge concern, but take from someone who has desperately tried to get the latest small form factor boards from industrial/embedded companies.  The first question they ask me is how many employee's my company has followed by asking if the number of board I'll need is in the 10 - 100 board range or the over 100 range.  Being able to obtain 1 board with retail support is a huge bonus.  While this is overpriced at $400, at least that includes the entire kit including the case.  I would also expect this price tag to fall in future iterations.

2) INTEL INSIDE (and its IVY BRIDGE)

While the Raspberry Pi is great for Arduino Fans and other ARM processors are Android ready, Intel and the x86 architecture remains the most versatile chip available.  Capable of running almost any operating system and it seems to be in intel's best interest to keep its hardware as operating system agnostic as possible.

This board is designed to have the most powerful architecture on it.  Although available in more powerful varieties, most small form factor boards are power-sipping, ATOM or FUSION based.  Not so here.  Yes, it is only i3 to start, but i5/i7 variants are supposedly in the works. 

3) EXPANDABILITY

At first glance the few USB ports and HDMI may seem paltry, but the one word that makes all the difference is THUNDERBOLT.  The next generation interface will allow for devices to be daisy chained as if they were part of the board itself.  Think of this as attaching daughter boards, if you want more usb ports, more display interfaces, more storage, no problem.  But, its even more, the PCI express speeds allow for connection to graphics cards is the need arises.  This allows you to build a board in any orientation and with whatever components you choose around a 4" square core.

4) GOALS OF USE

Despite the fact that it works, ECX/EPIC Boards are not intended for consumer computing and contain features that are somewhat wasted.  From security features to direct LVDS connections to dual gigabit ethernet to the ability to support a SIM card.  These proprietary features are usually left unused and in some cases even have to be disabled to make the boards more compatible.

All in all, I hope this board is a sign of things to come.  This is obviously a niche product, but most OEM computer products are niche at this point, from LED enshrined gaming cases to water cooling components.  The point is I believe that there is a market for people who want to incorporate powerful systems into small products and locations.  The smaller it is, the more extensive the options are.  But, I have to admit, I think the NUC would look fantastic in the base of an iMac G4.

The 17" iMac G4 Native PSU

Introduction

While I have not hooked the native PSU up to a mod and there is one wire that I do not understand the purpose of, I have checked all the collages of a working PSU.  I now know that is it similar in principal to the 20" PSU.  As this is all based off of my work with the 20", more information is available in that post:

The 20" iMac G4 Native PSU

17" iMac G4 PSU

vs ATX PSU

ATXPSU

The Native PSU is an always on, 12V only power supply.  Always on meaning that unlike standard ATX PSUs, the moment the AC cable is plugged into an outlet, there is DC power in the pins.  To get an ATX PSU to work without a motherboard, a pin in the motherboard connector needs to be grounded (known as "jumping" the PSU).

12V only means that unlike standard PSUs, only 12VDC and Grounds are supplied to the motherboard.   ATX PSUs transform the 120VAC in the wall to 12V DC and also downconvert the 12V to 5V and 3.3V.  These 3 different DC voltages are supplied to the motherboard in multiple rails via a 20 or 24pin connector.  Because the PSU supplies the iMac's motherboard with only 12V rails, the downconversion to 5V and 3.3V happen on the motherboard itself.

ATX PSUs also tend to supply peripherals directly, Molex, SATA power, 8pin PCIe etc emanate directly from the PSU itself.  As noted, ATX PSUs are not "always on", they have to be "jumped" either manually or by the motherboard.  As a result, the peripherals will not be given power until the motherboard is switched on, despite the fact that the power is supplied directly from the PSU to the peripherals.  Because the iMac's PSU only has 12V, the one molex line with 2 molex connectors (for the cd and hdd) emerge from the motherboard.  Although the molex wires share the same 16pin connector, it comes from the motherboard and does not interact with the PSU at all.  As the peripherals are supplied by the motherboard they will be off when the mobo is off despite the "always on" PSU.

The Connector

"Clip Side"

"Non-Clip" Side - All Grounds

The connector is 8x2 for a total of 16pins, one slot is empty for a total of 15 wires.  Of those 15, 4 (Yellow, Red, Black x 2) go from the main connector to the molex connectors.  Because we will not use of the original mobo, these wires connect to nothing and have nothing to do with the PSU at all.  That leaves 11 Power supply wires.  The blue wire seems to have no detectable voltage and grounding it does not seem to have any effect.  In the 20", the blue wire acted as the ground component (with a white wire supplying +5V DC to the PSU - the white wire is not found on the 17" - the pin is left empty) of a switch to turn on 24V DC supply to the LCDs backlight.

In the 17" the 24V Green line is replaced by an extra yellow +12V DC.  While I do believe this (similar to the 24V required by the 20" backlights) does go to the blue wire of the inverter to supply the power to the backlights, the "switch" to turn the backlights on works differently.  Here the extra 12V DC line is on as soon as you plug in the power cable.  This is the same as the other 12V lines.  No voltage needs to be applied to the PSU in order to get all the lines working.

So, I am not exactly sure the purpose of the blue wire.  Since, I don't have a working 17" mobo to even voltage test it.  I do have a theory, I believe it acts as a ground for a similar switch mechanism as seen in the 20", however, this switch (which also uses 5V) happens in the inverter itself, not the PSU.  I'll talk more abut this later.  For our purposes its really of no consequence.  What we are left with is 10 PSU cables, 5 Yellows and 5 Blacks.  This means there are 5 12V DC rails supplied to the motherboard, as soon as the iMac is plugged in.

The Pinout:

17" iMac G4 PSU Pinout

Please note this is an alteration of an image from my 20" pinout - hence the crude "photoshop"

Again I break it down into four zones:

1. Yellow Zone: Pins 1 - 4 and 9 - 12: 4 rails of 12V DC and grounds

2, Blue Zone - Pin 13 - The blue wire is the only pin (will not be used here)

3. Red Zone - Pins 6, 7, 14, and 15 - The molex connector comes out from here.  You will want to save the actual wires and connectors for use in this mod, but these pins are of no consequence.

4. Green Zone - Pin 8 and 16 - This likely is the 12V rail which the motherboard routes to the inverter, but since its automatically on and we aren't using the original mobo , its just another 12V DC rail with ground to us.

Getting a 5V Line:

The 2 plug connector connects to the AC port on the back of the iMac G4 which contains the C5 receptacle (The 3 pronged plug with 3 circles that resembles Mickey Mouse).  This plugs into the AC on the wall and there is +12V DC in our yellow wires.  In total there are 5 rails (Pairs of Yellows and Black Ground wires).  However, this mod calls for a molex adapter to be used as a PSU.  The molex adapter has a Yellow +12V DC rail and a Red +5V DC rail.

My switch theory (Optional Reading):

The 17" Inverter Pinout

For those of you that are familiar with the 20" PSU you may be aware that I mentioned in my post that a 5V line is not necessary to get the LCD working.  This is because the one place on the 20" that required 5V was "the switch".  This switch worked by the motherboard downconverting 12V to 5V then feeding it back to the PSU via the White/Blue wires.  The 5V turned on an upconverter (or possibly a transformer) that produced the 24V line.  +24V now flowed in the Green wire of the PSU, this went through the connector and got directly routed through the motherboard to the Blue/Red (+24V)  and Green/Black (as Ground) wires of the inverter cable.  When 24V reached the inverter the backlights turned on. On the 20", I used the 5V that came from the DVI cable.  As this is just a switch I was not worried about overtaxing the low current available in this line.  

For the 17" PSU, there is no switch involving the PSU.  The Yellow wire at the end (in the Green Wire's Place from the 20") is on as soon as it is plugged in.  However, I believe there is a similar switch mechanism, but it is in the inverter, not the PSU.  The 20" has 6 backlights, the 17" has 2 backlights, so I understand the need for (2) 24V lines and (2) Grounds.  In the 17" inverter cable there is (1) Ground and (1) Power Wire +12V via the Blue Wire.  Initially I thought that 5V was also somehow required to power the inverter, however after some experimentation, I realized the 5V required for the Red inverter cable acts as a switch and not as a true "power source".  Because of this, the Red Inverter cable can be connected to the DVI +5VDC power source.  Obviously this is similar to what I just described as the switch mechanism in the 20" iMac G4.

The 20" Inverter Pinout - Revised

Comparing the 2 inverter pinouts shows similarities.  The Orange (Dimmer) and Purple (Possible role in Sleep?) are left unconnected.  The 6 backlights in the 20" need two power rails, so both Blue and Red wires supply + current with Green and Black as their respective Grounds.  The 17" has 2 backlights and needs only one power rail, the Blue wire as + current with Black as its Ground.

In addition there is a Yellow in the 20" and a Green in the 17" that need very low current via Resistor connected to 5V.  This wire appears to be involved in wake from sleep.

All wires are accounted to except for the RED wire in the 17" inverter cable.  This wire uses 5V produced by the motherboard from downconversion of the PSU's 12V and uses it to "turn on" the inverter, acting as a switch.  This is exactly what the White Wire (which is missing from the 17" PSU) of the PSU does for the 20". Except it acts at a different location.  This also makes me think the remaining Blue Wire may somehow be a ground wire that the motherboard uses for this mechanism.  But, as we ground our 5V DVI Current via the DVI, it is not used.

Need for 5V and Preparing the PSU:

Although the inverter could probably all be handled by the DVI input (could likely get away connecting the Green inverter wire as well.  There is one more thing which requires 5V, the LCD itself.  The Gray cable of the LCD contains 3 wires which power the LCD screen.  In the 20", 12V is needed, but in the 17" 5V or 3.3V is needed.  As this is not just a switch, but actually powering something, I would not use the DVI source as you will likely overtax it.  This may actually damage your source, computer, video card etc.  So 5V must be created from the PSU.

At this point, I would recommend cutting off the motherboard connector to free all the PSU's wires.   Right above where the wires enter the connector cut them free.  This gets rid of the molex connector (you do not need the cut these 4 as they are not attached to the PSU itself).  You should be left with 5 Yellows, 5 Blacks, and 1 Blue (which will not be used) coming out of the PSU.

Option 1 - A computer in the base:

This is for how that are using some type of small form factor board i.e. Nano, Pico, or ECX.  Many of these boards are powered by a P4 connector.  This is a 4 pinned connector (2x2) that uses 2 - 12V and 2 - Grounds.  As there are plenty of 12V rails available from the PSU, simply take your motherboard power connector and attach the 12V DC lines to the Yellow wires from the PSU and the Grounds to the Black PSU wires.  In the picture of my KEEX-6100 below, the P4 connector can be seen in the front right corner of the motherboard.  This connector attaches to a 12V rail from the native PSU.

KEEX 6100 with P4 connector to Native PSU

The reason this will work is that this board (as well as several other small form factor boards) works just like the original iMac G4 motherboard in that it requires only 12V in to work and it itself has downconverters on it.  The KEEX-6100 actually has a mini-Molex/SATA power out port, which can be seen in the back, just left of the fan.  This gives a couple molex out, including 5V.  So you have a 5V line from here.  Just note that I would still recommend taking the 12V backlight power from a Yellow 12V rail from the PSU itself, but the LCD power and ground can connect to the Red 5V and Black-Ground line here.  The Green from the inverter can also go here or the DVI 5V as noted.

Option 2 - Use a second PSU - a PICO PSU connected to the native PSU

A PICO PSU with rocker switch

Almost all PICO PSUs use 12V DC input (some have wide ranges in DC input).  Power it by hooking a 12V line from the native PSU to the DC power in (the white and black wires pictured that hook up to the connector for an external power brick).  As the native PSU gives you 12V DC already, you do not need a power brick.  You must "jump" the PICO PSU in some fashion, depending on what your intended iMac G4 mod is.  The Jump mechanism can be "always on" with a simple wire or "on/off" with a rocker switch (as pictured) to control power out from the PSU.

If you are using a motherboard in the base that requires an ATX Power connector, this is without a doubt the way to go.  You can plug this into the motherboard connector, without having to wire all sorts of adapters and converters, at a negligible loss of space.  Of course if its connected to an ATX mobo, the motherboard will jump it for you.  

If you are using this for an external monitor with peripherals (ex. dvd drive), you can use the requirement to "jump" this psu to your advantage.  You can put a rocker switch here that will allow you to turn off everything its connected to.  Remember the native PSU will be on as soon as you plug it in, by jumping this psu without a switch, it will also be on.  Thus, drives will be spinning, leds will be glowing etc whenever it is plugged in.  With a switch here you can turn the whole unit LCD and peripherals completely off.  Just remember, no matter what wattage PSU you get, these are not additive, they are connected in serial, so you are still limited by the overall wattage of the native PSU.  Also, you have to make sure that the wattage is adequate for anything you have connected "downstream" of PICO PSU including the LCD power (though the backlights can be connected to either the native or PICO PSU).

The PICO PSU is probably the most flexible option as they are available with P4 connectors. molex connectors. SATA power connectors etc.  If you are not using an ATX motherboard, you could even use the power from the pins intended for the motherboard.  However its expensive and not needed if you use Option #1.  And if you aren't using peripherals requiring 5V - you can likely use the cheaper option #3.

Option 3 - Use a 12V to 5V DC-DC Downconverter

15W 12V to 5V DC downconverter

These can usually be found for around $5.  Connect one 12V and Ground in and you get 1 5V and Ground out.  Combine this 5V rail with a different 12V from the native PSU.  With a 12V and 5V rail, we now have our "molex wires" that acts as our power source.

All these are acceptable, as is using a different PSU altogether, it simply depends on your goals and needs.  As always - thanks for reading!!

17" iMac G4 (1/1.25Ghz Neck) Video Tutorial

What you see here can be applied to the other iMac G4's, just use the correct pinout.  This is the first time I have ever done a mod in front of the camera and this was more difficult than I anticipated.  This was done live in real time (for the most part).  I sped through the portions that were simply repetition (such as stripping a wire or pushing out every last pin) and did cut very small portions (mostly because I felt I said or did something confusing).  I do apologize for frequently pulling out of the shot, its hard to work on a small item with a camera in-between you and the project itself.  I still believe this is useful to people who are better at visualizing than pinouts or snapshots.  Also, you can get a sense for the time this takes.  While soldering and stripping can take days, without the camera and explanation, I could have finished this in an hour.

There are a few highlights:

-  To make the extra wires I used the iMac's own ground pins.  This worked great and saves you having to buy an extra neck.  This is certainly the way I would recommend proceeding at this point.

-  Frustratingly, I have purchased a refurbished 17" 1ghz neck to use in this demonstration (as I did not have any more completely intact ones).  It did have some variation in that in the black lcd cable, one of the four wires in the black cable, the Red Wire was replaced with a Gray/Off White wire.  In addition all the the positive TMDS wires that emerge from the four wires that are usually Red, were also Gray/Off-White.  I have seem a random color variation in refurbished necks before, however, it was frustrating that for my demo, this one had more variation than I have seen before.  So just remember, for the black LCD cable Gray = Red.  And also be aware that this variation does exist.

- The final part that involves connecting the Red Inverter Wire to the VEDID/Pin 14 is very important because of the way we have it setup.  The inverter will not turn on appropriately unless this step is done.

-  When making the extra cables from the 3 ground wires with pins in the iMac's Gray Cable, I add one extra wire (a black wire I took and stripped from the iMac's fan cable).  The wire is not really necessary, you can hook the resistor directly to the other wires, but I feel that one extra wire not only makes it more secure, but also gives an extra area when we split again by adding the Red Invereter Cable.  Remember this actually becomes a 3 - way split with 1 split going to the LCD via the iMac's own Red/Hot Pink wire, 1 split going to a resistor then back to the DVI via Pin 16, the hot plug detect, and the final split going to the Red inverter wire.  So the extra wire allows us to kind of split once, then split again, as opposed to a direct 3 way split.

This has also been integrated into the blog, but here are all 9 parts together:


Part 1: Introduction and Parts List

Part 2: Completion of the Parts List

Part 3: Freeing the Inverter Wires

Part 4: Freeing the LCD Wires

Part 5: Hooking up and Testing the Inverter

Part 6: Connecting the Black LCD cable

Part 7: Powering the Gray LCD Cable

Part 8: Hooking up the Gray LCD Cable

Part 9: Finalizing the Inverter and Demonstration

Hope this helps and good luck.  Thanks for reading and watching!

iMac G4 Mod Advice

I hope this doesn't come across as preachy, but I just want to give some advice to those of you new to modding the iMac G4.  I have disassembled and reassembled this computer so many times I could probably do it blindfolded.  There are a few aspects of modding this computer that have led to a lot of frustration for me, a few pointers, hopefully, will help some of you.

1) If your goal is to connect your iMac G4's LCD to modern hardware.  Use the Native LCD with the "TMDS to DVI Method".  Changing all the wires to some other method of connection such as LVDS is very time consuming, less stable, and more expensive.  There is no reason not to use the native TMDS wires that go from the native LCD through the neck.  Apple has already done the work for you! Plus, TMDS is a digital signal that is more stable over distance than LVDS and TTL.  Apple has put the controller inside the LCD itself, with other LCDs, you would have to add one.  I have done this both ways, replacing the screen and replacing/soldering the wires takes hours and likely days.  By using the TMDS to DVI Method with the DVI Connector below, you could get a signal within 30 minutes that is superior in every way.  Which brings me to.....

DVI Connector

2) USE THIS DVI CONNECTOR!!!  (MOLEX PN 74320-4004 - though other variations which work just as well exist).  It is very cheap and makes this mod so much easier.  I can not emphasize this enough. I know a male HDMI may be more convenient (or even a male DVI), but for the price of an adapter you will save yourself a lot of frustration.  Sure you could cut off an HDMI cable and solder it to the iMac G4's pins, but this is a much harder task than you may think.  The TMDS channel wires in the Black LCD cable are as thin as a hair and this is no exaggeration.  If you manage to spare the pins at the end of the wires during soldering this can be done.  But, as the pins are soldered to the ends of the wires themselves, they have an annoying habit of falling off when heat from a soldering iron is applied.  Also, if you make a mistake while soldering there is no going back.  As this is a digital signal, one broken connection can mean no signal at all.  What's more is that even if you do things perfectly, you can still have signal problems.  One mod that I made I had to cut and reconnect again (so I lost all the pins).  Despite a perfect connection, the image was plagued by artifact.  Another time, I had red/green pixels "dancing around" when viewing certain colors.  I ended up having to replace the entire Black LCD cable (with the TMDS signaling cable from an Apple Cinema Display which has thicker wires) to solve the problem.  TMDS uses minute differences between the positive and negative wires (and their shield wire) to communicate.  Altered resistance in the form of a little too much solder or too much wire wrapped around can result in these types of artifacts even if you are extremely good with soldering.  This DVI connector makes this almost plug and play.  The pins fit perfectly,  you don't need to solder at all.  I am not exaggerating when I say that this method saved me 10+ hours of intensive work on my recent mod.  Besides having to put a piece or two of electrical tape over some pins to prevent cross-talk, my image has been pristine every time I have used this connector.  Do not repeat the same mistakes that I have made.

iMac G4 Neck with Cinema Display Wires

3) Although no longer necessary with the TMDS to DVI Mod, if you want to add or change some wires, do not be scared to open the neck.  Its not hard, does not require special tools, and is not really dangerous.  I have written on this blog about the exploding neck because I had read about it myself.  I've had an open neck fall off the table, I've left necks open for weeks at a time, and have never had the spring fly off.  I wouldn't throw an open neck as hard of you can against the wall, but you do not have to handle it like its plutonium.  Just keep in mind that  if you do knock the spring off its moorings it takes a lot of work to pry it back up into position.

4) If you need to add wires to the neck, do not put more/thicker wires into the neck than it can hold.  Just because you can get it through the holes does not make it a good idea.  When you overcrowd the neck, you'll start to hear grinding and some wires will wear down as they are pushed into the hinges of the neck.  The iMac G4 has 4 wires that go through the native neck.  When you replace wires, take out what you're not using and aim to have about the same "volume of wires" as the native neck comes with.

5) Get rid of the Torx-6 screws.  These are the most troublesome screws I have ever worked with.  On the bottom of the 17" and 20" iMac G4's monitor housing you will find 3 screws that require a Torx-6  screwdriver to open.  These are the screws that keep the monitor housing closed.  I have never seen screws that strip easier despite using the appropriate tool.  6 points on a tiny screw is very close to a circle and once you start stripping it - its already too late.  Chances are good that you may have to open up the monitor housing again at some point for upgrades, repairs etc.  Act preemptively and replace these with small phillips screws - it will save problems later.

5) Want an All-In-One? Consider an 3.5" ECX or other small form factor board.  Although mini-itx or a mac mini motherboard are the most popular choices neither of these is ideal from a size/heat perspective.  ECX's can fit at the top of the dome in place of the native HDD where heat won't be as big a problem as it would with a mini itx at the bottom of the dome.  They don't require an atx power supply and come with a variety of additional options including PCI-E mini or x4, Compact Flash etc.  Processors range from Atom to AMD Fusion to Sandy Bridge Core i processors.  This allows you to keep the full 5.25" drive if you want and allows room at the bottom of the dome for ports at the back.  Although not nearly as expandable as a mini-itx mobo, with such limited space in the dome, this isn't likely to matter.

6) Do not sacrifice stability for power.  The mods I've posted usually don't include the mods which failed.  Most of these initially worked but failed because I tried to force things.  If you have to use all your strength to push your mod closed to screw it in, it will not last.  If you cram things in between the motherboard and the air holes, your board will overheat.  Keep expectations in check.  If you have a 17" monitor running at 1440x900 you don't need SLI or Crossfire.  Having it turn on and having a critical problem like this is worse than it not working at all.  If it does not turn on, you can start troubleshooting what went wrong.  These problems (like my 20" TMDS to LVDS with too many wires through the neck) usually require a complete redesign and many of the parts have to be repurposed or replaced altogether.

Hope this helps.

Anniversaries and an iMac G4 "Sandy Bridge Mod" Pro Version?

I hadn't even realized that I failed to acknowledge an important anniversary.  The iMac G4 was introduced on January 7th, 2002 by Steve Jobs at the San Francisco Macworld.  The 20" was released later in November 18, 2003.  Then only 2 and a half years later (August 31, 2004) the iMac G4, with its sunflower inspired horizontal design, was discontinued in favor of the iMac G5's vertically oriented all-in-one.

Many reasons have been suggested to why this was done.  The cost of the neck, the difficulty in supporting increasing LCD sizes, and the cooling needs of the notoriously hot G5 processor.  I have been using one version of this as an external monitor hooked up to a mac mini and now a second version as a modernized all-in-one and it remains one of the most enjoyable desktop user experiences I have know, even 10 years later.

With my sandy bridge "genuine" mod my goal was to be as true to the original as possible, but I have been thinking about doing a version that has some extra features not found in the original.  Some of these may be possible, some of them are not.  To make extra room in the base, the optical drive will be removed.  So, I am contemplating doing a "PRO" version of the iMac G4 mod.  I have enough spare parts and I think this may be a fun alternative.  I will likely use the TMDS to DVI method and not the apple cinema display controller method.  The overall look of the iMac G4 will be changed (something I wanted to avoid in the previous mod).  Things I may add:

3M Touchscreen

• A Touchscreen: One of my favorite mods used a resistive touchscreen and it fits this form factor quite well.  However, I did not like the glare, resolution, or touch accuracy of the resistive touchscreen.  I have however located a capacitive touchscreen that should fit in this mod.  Its flaw is that it is somewhat thick and heavy.  An alternative may be incorporating optical sensors in the bezel.
• LED backlighting: This would be necessary to fit the touchscreen, but something that has been done in similar projects by JL7, and adds improved backlighting and power efficiency.
• Quad Core Processor: I changed from a mobile core i7 quad core to a dual core i5 as a result of both heat production and power consumption in my latest mod.  However, a quad core i7 machine is still something I would love to do.  As well as maxing out the RAM to 8GB.
• Native Power: Increased power needs would require a big power supply and the only one that could fit is the native supply which other modders have used.
• Better Cooling: Use of the native PSU would require shifting of the mobo downwards.  This as well as heat generated by the quad core processor and the PSU itself would require a much more powerful cooling solution.  At the very least a large active heatsink on the CPU and a 92mm case fan.  However, an intake fan at the bottom may be needed as well.  This will use of the space that was previously used by the optical drive.
• iSight Cam: in my G4/G5 setup, I use the iSight cam on the G5, but I have been wishing that there was one on the G4's LCD as it would be much easier to manipulate.  The microphone is already there, modifying the LCD enclosure to support an iSight may be possible.

iMac G4 iSight Mock-up

• Apple Modification: Just to visually delineate this, I was considering altering the apple on the base.  A light up apple or IR sensor are possibilities
• ???Improved Graphics: This one is difficult, although its something I would like to add, most of these small boards do not have PCI-Ex16 slots.  Even conversion of mini pcie is usually only to x1, and this makes it difficult to get much improvement over on chip sandy bridge graphics.  Fitting and powering a full size card would also be difficult.  I will continue to give this thought, but its probably unlikely.  Even if you wedge a mini itx in, you would have difficulty fitting even a low profile card in to the dome.  

Although this mod would involve tradeoffs including louder fans, loss of the optical drive, and loss of the exact iMac G4 appearance, there are clearly advantages as well.  The iSight, LED backlights, and touchscreen in particular are things I would love to add.  Any suggestions would be appreciated.

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.