20" iMac G4 NUC/AiO Ivy Bridge Mod: SUCCESS!

20" iMac G4 / NUC Ivy Bridge Mod

Updates:

I'm happy to report that all problems have been solved and the motherboard fit test was successful.  This is currently the method I would recommend for those that want a 20" Ivy Bridge Hackintosh version of this mod.  As I noted in my previous post, while I initially believed I would not go in the direction of the NUC board, its remarkably small size and simplicity made it by far the best candidate for this mod.

Original vs NUC/DVD - Front

In multiple previous posts I have explained the advantages of having the core elements (processor/motherboard) of the mod at the top of the dome where ventilation is best.  In my previous ECX mod, the board only fit with the optical drive because I did not use the native PSU.  Because I wanted to use the native PSU, I did not believe fitting the optical drive was possible, but with this board it looks like it is going to fit. (Although nothing is definite until this is completed).  This board fits into the slot left vacant by the 3.5" HDD (the mSATA is on the mobo itself).  It pretty much fits into the grooves in the drive chassis requiring no alternation.  For comparison, I have taken side by side photos of the original optical drive and HDD in the drive chassis next to the shorter new dvd optical drive and the NUC occupying that area.  The height is pretty much the same and there is amble room for the connectors to fit as well.

Original vs NUC/DVD - Top

Problem Solving:

With this fitting at the top of the dome, I should have even a little but more room for components than I did with my previous mod.  This is because, there are less port extenders needed and no SSD is required at the bottom of the dome.  It will still be tight, but I have some wiggle room to address the problems that I brought up in my previous post.  Taking them one at a time:

1) USB Ports: A 4 port USB Hub leaves me with only 1 spare USB port, but solves the problem.  The addition of another hub or a larger one is likely.  A USB port supplies the 5V to the PSU.

2) The Fan: The directional fan is connected to the heatsink and I did not want to remove it.  I also wanted to keep the case fan.  Apple's connectors and colors are completely backwards from industry standards (Black is 12V, Red is Ground and the fan out is a 3pin Male connector, not Female).  The fan is also somewhat loud and old, so I decided to replace it.  I bought a Antec 92mm fan that had a molex out (there is no case fan output on the board).  There is a sense pin that I won't be using.  Because I won't have software fan control, I got a model with a 3 speed setting.  I put it on medium to reduce noise and may extend the controller to the back ports or simply leave it on this setting.

Wide Input Pico PSU

While 12V are readily obtainable from the PSU, the problem is that the PSU is always on.  So, the fan will spin as soon as the computer is plugged in, no matter if the computer is on or not.  As the computer does not have any 12V out, I will have to use some kind of switch.  Luckily, the PSU comes natively with a "switch".  The PSU relies on the motherboard to downconvert 12V to 5V then feed 5V back to the PSU to turn on the 24V line that powers the monitor's backlight.  Although there are many other ways to do this, I went with an elegant solution using what I had available.  Keep in mind this is not the only peripheral that needs power.  The optical drive requires 12V and 5V in either a molex or SATA power connector.  Luckily, I had a very small 20 pin PICO power supply with a WIDE INPUT range up to 24V. (Not all PICO PSUs can accept 24V, may sure before you connect).  I spliced the PWR input to the Green wire of the PSU (24V) which connects to the Inverter Wires as well.  I connected the ground to a native PSU ground.  As this is a standard 20 pin ATX based PSU, it won't work without a motherboard unless you ground the On Pin.  I have it connected to a switch, but will likely just leave in a wire, allowing the PSU to turn on as soon as it receives 24V DC input from the native PSU.  This produces the necessary 12V and even a 5V and has both a Molex and SATA power cable out.  I connected the Molex to the Fan (you only need the 12V line and ground), and the SATA to the optical drive.  Now we the peripherals will only turn on when the motherboard itself is turned on.

PICO PSU powering the optical drive

The Bypassed Power Switch

3) Power Switch: I did not want to damage the board, so I simply threaded small wires between the onboard switch and its solder points.  I did this to the front right and back left corners.  This was then wired to the case switch at the bottom of the dome.  These can be easily removed in the future if this board is ever repurposed.  In addition this does not effect the functionality of the original switch in any way.

The case switch I use is from my previous mod. Modeling clay was used to secure a momentary switch directly behind the peg that protrudes from the back of the plastic power button on the back of the iMac dome.

4) Audio: I am sticking with the Turtle Bay USB Audio solution from my last mod.  This allows for a standard 3.5mm audio jack out and also supports a 3.5mm Microphone in.  I have it wired to the microphone in the LCD housing.

5) Bluetooth: I have not found anyone who has had success with any half height mini PCI-E that supports Wifi and Bluetooth with Mac OSX.  So, I am simply going to keep my very small USB bluetooth solution.

6) Optical Drive: I am using a DVD Burner that gets power via the PICO PSU discussed in #2.  The connection to the mobo is via a SATA to USB 2.0 adapter cable.

12V to 19V DC-DC Upconverter

7) Power: While the option of splicing the AC to the to the existing AC plug with the NUC's powerbrick is not a bad one, it is somewhat of a waste of the 180 watt PSU that already exists in the machine.  Not to mention that I'm already including a second PSU (which is really being used only as a downconverter here).  The NUC requires 19V at (at least) 3.7A and the PSU is only supplying 12V (can't use the 24V because its only on with 5V from the motherboard).  Luckily, 19V is the typical notebook operating voltage and therefore upconverters are available.  Though there is a much smaller selection than for more common voltages (24V, 12V, 5V etc).  Many different shapes an sizes are available.  I got one in a familiar shape on ebay from a Chinese manufacturer for $20.  Its relatively small ( I may remove part of the heat sink surrounding it) and is a 12V DC to 19V DC upconverter at 4A.  This is exactly what is required and works flawlessly.

The Upconverter connected to PSU and NUC

The Upconverter gets 12V and Ground in from the Native PSU and sends 19V out.  I had a broken Laptop AC power adapter that had a DC input that perfectly matched the power in plug on the NUC.  The positive is the inside peg and the negative is the outer part.  Using a multimeter I ensured which wire was which and connected this to the power supply via the up converter.

The Fit Test:

The Secured NUC Motherboard

On a side note, I used a rubber sleeve to cover the drive cage where the NUC will go.  After some guess and check, I determined the place where the  NUC and USB connectors seemed to fit the best. To test fit, I used twist ties that went through the screw holes in the grooves intended for the HD and then through the motherboard screw holes.  These will be replaced with plastic locking ties to secure the motherboard in place.
One thing to make sure of is that the wifi antennae which goes through the metal faraday cage (Wifi signal will be severely reduced if the antenna is within the cage) is connected to the wifi card before the board is secured.

Build Pics:

A Mess of Wires, But A Working Mod

Video and Audio Test

Motherboard View

About This Mac Screen

Remaining Issues:

Obviously, there is a lot of cable management to do.  This will get much simpler once connections are directly soldered (connectors removed and alligator wires eliminated).  As I technically have more room at the bottom of the dome than the previous mod (also had a DC converter and a PICO PSU to deal with), I do not believe this will be difficult to fit.  The wire management, however, may be more involved.

There will a paucity of ports.  A 3.5mm audio out, a few USBs, and not much else.  If I had to do it over, I probably would not have bothered spending the extra money on the Thunderbolt equipped version.  There are so few available peripherals and there are so overpriced that I can not even test this. Perhaps this is somewhat future proofing, but I would imagine there will be further upgrades to this board before thunderbolt actually takes off (if it ever does).  That said, I would not have bothered with an ethernet extender anyway.  I've learned with this that the more you do, the more that can go wrong.  I am more than happy to keep it simple.  I also have the option of adding a powered USB hub with the 12V lines in the PSU.  Unlike my previous mod which was very close to its power maximum, this should have room to spare.

Concluding Thoughts:

Untili I have it assembled and have worked with it for a while, I'm cautious about speaking too soon, but I am very optimistic about this project.  Although to Core i5 Sandy Bridge to a Core i3 Ivy Bridge may seem like a lateral move, this board is simply a better fit.  Its lower power, quieter, and everything onboard works.  The incorporation of the native PSU while keeping the optical drive makes this virtually indistinguishable from the original 20" iMac G4.

Hopefully will finish soon! 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!

 



The Two 17" iMac Necks

*NOTE: The Inverter Charts have been updated.  As I noted earlier, a reader noted flickering of the backlights with 12V connected to the RED line and it stabilized when connected to 5V.  I initially thought there was some inverter variation but after another confirmation from a reader I checked my old notes and had clearly written "Red - 5V".  I made a mistake when putting together the Inverter diagram for the blog.  Thank you to my readers and my apologies for any inconvenience.  Please note the charts have been corrected to reflect that RED is connected directly to 5V for both 17" iMac necks.

So I have fairly intact versions of both of the 17" necks and they are VERY EASY to tell apart - even if you don't know which 17" iMac the neck originally came from.  They are also VERY DIFFERENT - so know which one you are using before proceeding.  These are the only two part numbers for 17" necks I have been able to find.  Other variations or small differences may exist, I can not be certain.  Remember, you always have the option of opening up the monitor and looking at the JAE connector.  Because they all use the same LCD, the pin number/position will always be the same.  I will focus on the differences.
My previous post/17" pinout detailed what I will call:


NECK A: This is part #661-2825 and is the for the 1ghz and 1.25ghz 17" iMac G4.

 Here is a picture of the JAE connector.  Notice that the pins are glued onto a black board which is then encased in a silver connector with prominent push clasps on the sides.

 Here is the inverter - LCD side.  Notice the colors from left to right (Blue, Black, Red, Green, Purple, ORANGE)

 Bottom of the inverter again you can see the presence of an ORANGE wire

 The bottom of the video cable that plugs into the motherboard had this number on it (620-2305).  I don't know if this is universal across all of these necks, but I wanted to point it out).

DVI pinout A - 1 or 1.25ghz iMac neck

Inverter Pinout A: 1 or 1.25ghz Neck

So here again is the DVI and Inverter pinouts for Neck A recognizable by:
1) Part #661-2825
2) Comes from a 1 or 1.25ghz 17" iMac G4
3) Has a black/silver JAE 30 pin connector to LCD
4) Has an Orange Wire in the inverter cable
5)??Has the number 620-2305 on the motherboard side of the video cable

NECK B: This is part #661-2716 and is the for the 800mhz 17" iMac G4.

I have peeled back the aluminum foil, but you can see that the JAE connector that connects to the LCD is one where the pins snap into a beige connector and there are no clasps on the side.

Here is the inverter (LCD side).  Notice the colors from left to right (Blue, Black, Red, Green, Purple, OFF-WHITE) 

 The bottom of the inverter (removed from connector) again shows the OFF-WHITE colored wire [NOT ORANGE].  There is also a number on the motherboard side of the video cable.  Again, I'm not sure how specific this is.  (620-2122).

So here is the new TMDS to DVI and Inverter pinouts for Neck B recognizable by:

1) Part #661-2716
2) Comes from a 800mhz 17" iMac G4
3) Has a beige JAE 30 pin connector to LCD
4) Has an Off-White Wire in the inverter cable
5)??Has the number 620-2122 on the motherboard side of the video cable

DVI pinout B - 800mhz iMac neck

Inverter pinout B: 800mhz neck

*** I have come across a neck that has the LCD cable of a 800mhz iMac, however, its inverter cable has an orange wire.  As I obtained this second hand, this could have been the result of a repair and may not be standard.  As both are left floating, it doesn't matter for the inverter, however, I can now have doubts if this can be used to differentiate the two necks.  Luckily, there are other differences.

Conclusion:
There are so many differences, there is a Brown cable in one, an Orange in the other.  The order of the rest of the wires is completely different.  Even the Clock/Data cables are reversed White/Black.  While I myself have set up Neck A, a reader of my blog has gotten it working with neck B.  Obviously the color of the wires really doesn't matter its what pin they connect to thats important.  As there may be a slight difference in what I call "blue vs. purple" etc.  Here is a close up of the 2 JAE connectors and the order of their wires (pin 1 position is on the left to pin 30 on the right).

NECK A: 1 or 1.25ghz 17" iMac

I'm excited to see some of the projects people come up with - I also like confirmation that things are written clearly and are correct.  So comments are appreciated - thanks.  Good luck and feel free to ask any questions.