20" Lampshade iMac G4 running Lion via Sandy Bridge ECX mobo

[jberg44]

[video=youtube;zN6z-VXlnvg]http://www.youtube.com/watch?v=zN6z-VXlnvg[/video]

NearComplete.jpg

Not quite finished, but very excited as everything fit inside the dome. This is a mod of a iMac G4 20" casing and LCD. This uses the unaltered LCD and neck, but the video cable is converted to provide a DVI/HDMI signal. A 150 watt pico Power Supply powers the both the LCD as well as the computer.

The motherboard itself is a small, yet powerful Sandy Bridge Mobile ECX board made by Quanmax called the KEEX-6100. This board is only 3.5" and fits nicely at the top of the dome by the exhaust holes. As this is a mobile chipset and I'm using the G2 socket mobile variety of the i5 processor, the computer is identified as a MacBook Pro.
ScreenShot.jpg

The main drive is a 2.5" SSD and a full 5.25" DVD Drive fits as well. installing Lion was done remarkably simply using Unibeast (Thanks Tonymac!!). Only the Crummy Onboard Audio had to be disabled. (I'm using USB for sound). Gigabit Ethernet works, The Broadcom PCI-Express Card from a Macbook pro fits into the PCI express slot and hooks into the antenna that is present within the iMacs plastic dome casing. Wake from sleep is the only problem I've been having, but haven't yet tried to fix it. I plan on using the Powerwave USB adapter to use the original Apple Pro Speakers. Even the power light and microphone in the LCD's case case work.
OpeniMac.jpg

I just need to work on the ports in the back (a few USB's, power connector, on/off switch, ethernet). Once thats done, I am hopeful that this computer will be indistinguishable (save for differences in the rear ports) from the original PowerPC iMac G4. I'll post video when this is totally complete.

I know this is not the traditional mod, but this is a Hackintosh inside an Apple case with n Apple LCD. I also can not thank Tonymac enough, the Unibeast process is unbelievably simple and because of it, I have given new life to a broken 20" iMac G4.
- JB (Dremel Junkie)

 

[minihack]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

That's really great and makes a very welcome change from the usual mod.s.

It'd be fantastic if we eventually managed to breathe new life into all the old Mac models - the true meaning of recycling!

Good luck with the rest of the mod. and well done in tackling something out of the ordinary with such a fresh approach.

 

[minihack]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

You know, that board would also be good for a Cube mod. and make a super easy media PC. I have googled it but for the life of me can't see where you would buy it from - is it just direct from Quanmax and would you mind revealing the cost?

 

[minihack]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

Another quick comment - I see from the datasheet that the sound board is ALC662. I have that codec in my Zotac and with a couple of tweaks to DSDT and a hex edit AppleHDA.kext can be made to run it......no need for your USB solution.

 

[slowjin]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

You know, that board would also be good for a Cube mod. and make a super easy media PC. I have googled it but for the life of me can't see where you would buy it from - is it just direct from Quancomm and would you mind revealing the cost?

https://www.sliger.com/

These guys are supposedly US distributors of Quanmax products. Very interesting build and board selection!

 

[Gus]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

This is very very nice! I love the g4. Have an old 17inch one waiting for some form of mod. Out of interest why and how did you make the apple lcd convert to hdmi.(possible make a guide) Is it not ldvs? Could that not be connected straight to this board? Im not really sure but the board has something labeled as a lvds socket. Or am I getting the ibook/macbook screens confused with this one.

 

[tviolation]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

Very nice work jberg! Glad to see one of these done that stays as an all-in-one computer. I've browsed your blog extensively in the past as I've been thinking of doing something similar but with a different approach for the motherboard and you've done some really neat hacks with these iMacs. I'm also curious about the LVDS connector like Gus mentioned as it seems like that could eliminate a lot of the extra work.

 

[jberg44]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

Thank you for all the kind words and helpful advice. That's great that I can use the onboard audio. Though I still may use USB to keep the original speakers and use the griffin powerwave, it's great to have the option. There is an onboard amp, but at 2 watts I think it's just too weak to use. I was wondering if anyone had any idea about wake from sleep, which is the last remaining problem. When I hook it up to a Mac mini there is no problem with wake from sleep, so I know that it's not an lcd design problem.

I did in fact purchase this from sliger.com. They are a licensed Quanmaxx distributer and I have found their customer service to be fantastic. When I had a question I was contacted by the owner himself. I believe I paid ballpark $180 for the board (but don't quote this number exactly) and some accessories. Remember though the mobile processor is separate. I know this is pricey, but it's a good sandy bridge board, that runs a mobile chipset (which is an advantage in these cramped mods). I've tried this with a mini itx and although you can wedge it in there, it doesn't work. There is no airflow because it can only go at the bottom of the dome. Anything else you put in has to go above it which further obstructs ventilation in the metal faraday cage. The smaller ECX board sits right at the top directly underneath the air holes. Also this allows you to keep the DVD drive, which is an important part of the G4s design. The current internal design I'm using will place the 2.5" SSD at the bottom of the dome under where the airport and ram access panel was. I believe the drive is the thing I'm most likely to want to "swap out" and this way it's available or quick access.

I had the Same exact thought regarding the cube. Similaly mini itx boards barely fit and even with modification youre usually constrained to low power atom boards because of heat issues. The ECX board or a nano itx would help with this. I have a older KEEX the core 2 duo 4030. As there was no AHCI option in its bios and the onboard graphics are not natively supported I did not try to hackintosh it, but I may try to put it in a cube to see how it fits.

 

[jberg44]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

In terms of LVDS there are actually 2 LVDS outputs on this board. However, I would not use these or go the LVDS route at all. I've gone the LVDS route and I highly recommend against it. The LCD panels in the iMac G4, G5, and Non LED Aluminum Cinema Displays contain a Texas Instruments chip inside the LCD that is really a mini LCD controller that converts TMDS to LVDS. Although some of the G5 panels may allow LVDS pass through, the G4s do not. So with LVDS you have to start off by replacing the LCD panel. Off the shelf options are hard to find as the 16:10 aspect ratio, especially for 20", is pretty much extinct. And no other inverter will fit inside the LCD housing (putting the inverter in the base would mean that very high voltage wires would be traveling through the metal neck). Secondly, the wires that run through the neck are TMDS wires (4 pairs, each with a shield wrapping around them). So changing to LVDS means opening up the neck and replacing pretty much all the wires. Also, LVDS is not standard, there can be variation in the number of grounds, power, order of pins, and polarity. This board can only give 3.3v or 5v of power to the panel, the 20" LCD needs 12v, so you'd be capped at 17" as well. And you would not output at the panel's native resolution, but at whatever the ECX board is set to (as this becomes the controllerbin essence and I'm not even sure 1680x1050 is an option. Also, apple did this for a reason, TMDS is stable over distances, LVDS is less so. I used to think, god I wish there was a board with TMDS out. But the thing I realized is that almost all modern boards do, including this one. HDMI and DVI don't get converted to TMDS, they are TMDS. It's really just the type of connector that varies.

So Apple has essentially put a complete monitor, internal LCD controller, and external but specially made very thin inverter into the LCD housing and connected it to an HDMI/DVI cable which they have already shielded and wired through the neck for you. Even more I luckily stumbled upon a female DVI connector (cost <$5) whose male pins are a perfect fit for the female pins on the TMDS cables in the iMac (previously soldering the hair thin wires was a frustrating nightmare at times). All you have to do is remove the iMacs connector to free the pins, push 14 pins into this connector, add an additional wire with resistor, and hook up grounds and power for both the panel and inverter. I have tried to simplify the power scheme of the 17" so that all power requirements terminate in one molex connector. The 20" is somewhat more complex. To use LVDS could take 20 hours of work, cost a couple hundred bucks, involve at least 30 solder points, and may not even display at the proper resolution. TMDS/DVI/HDMI with the above method can be done no soldering required, cost $25 or so, and be done in 20 minutes.

With the addition of the KEEX 6100 and tonymac's magic - a sandy bridge all-in-one appears can be done for a reasonable amount of money and not requiring any extraordinary skill.

tviolation - thanks for reading. This was one of those weekend projects that somehow ive now been working on for 2 years and counting. I've had many different variations and approaches. I've had plenty of help along the way, but I'm now quite close to completing what really was my original goal. And I hope my guides allow others to duplicate and improve upon. Any suggestions, ideas, or comments would be appreciated.

Gus (and any one else interested) - not only do I have the pinouts, but I have a parts list and a very detailed step by step guide for converting the 17" to DVI. There a 2 kinds of necks, for 17" so make note of this. see this post:
http://dremmeljunkie.blogspot.com/2011/ ... ds-to.html

This current 20" all in one project is detailed here for hardware:
http://dremmeljunkie.blogspot.com/2011/ ... ds-to.html

And here for software:
http://dremmeljunkie.blogspot.com/2011/ ... roars.html

A summary of all my iMac g4 mods including the LVDS ones can be seen here:
http://dremmeljunkie.blogspot.com/2011/ ... -mods.html

Hope this is usefull, JB

 

[minihack]

Re: 20" iMac G4 running Lion via Sandy Bridge ECX board

Hi JB,
Many thanks for posting here - I think it has got a lot of us thinking.
If you would like to post your DSDT to here (or to the DSDT forum perhaps) then maybe we could take a look and see if we can add the functionality for attempting Sleep and a few bits and pieces. I know I'd personally be very happy to take a look and contribute some edits to try - having tackled a few laptops and non-gigabyte boards I am starting to get used to the frustrations of DSDT editing.
I assume that you got this working without using a modified DSDT. In which case extracting your native DSDT from OSX is quite easy. My favourite method is to use the Application DSDTse which is a good little extraction programme with editing features.
All best and I look forward to hearing more.