Hinsight4 15" iMac G4 Intel NUC Upgrade

[hinsight4]

I'm new to the site but after knocking around the idea I'm taking the plunge to upgrade a 15" iMac G4 to a newer Core i5 based system (NUC). This will catalog my attempts in following the great tutorial by Ersterhernd here.

I picked up a 15" iMac G4 off of ebay for $30 plus shipping to get started, even though the posting was for a 17" unit. Had to lookup the serial number to verify that it was indeed only a 15" unit.

 

[hinsight4]

So far I have managed to remove several components from inside the iMac itself, including:

• motherboard
• original fan
• CD drive
• HDD
• 2 halves of the power supply
• internal speaker

At this point in the build there are only wires coming down from the neck for the antenna, TDMS signal and the LCD inverter.



CD and HDD removed, but you can still see the 2 halves of the PSU tucked up there and the speaker/fan in place.





Starting out by removing the bottom plate of the unit.




Case opened up and the bottom half of the dome completely detached.




Everything except for the speaker removed from the unit.

 

[hinsight4]

As of last night I have removed most of the "high points" on the original motherboard to make it slimmer and cut it with my dremel tool to maintain the existing mount points for securing it to the base.

I have not yet removed any of the existing IO ports from the back.

 

[ersterhernd]

Looks great so far! Always a good thing to see another iMac build on this forum.

I could not get the 3 iMac G4 USB ports to work right, due to cross-talk. I think they share a common ground and/or 5V supply. On my 2 iMac G5 projects (done after the G4 builds) I managed to carefully cut the traces between the existing USB ports and successfully isolate each port. I think in hindsight this may be possible on the G4 as well. Once the common connectivity between the 3 ports is severed, they work individually as needed, and its just a process of soldering 4 wires to the traces of each USB port.

You'll save yourself some headache with mounting your own USB ports if you can get this work, I'd say its probably worth a try while you still have the original ports in place on the G4 logic board.


Keep the photos coming. Good Luck!


Ersterhernd

 

[hinsight4]

Thanks for the tip! That makes some sense to me, but believe that sounds a bit outside my skills to reuse those ports on the existing board and wire them into the NUC. I like the idea though!

Looks great so far! Always a good thing to see another iMac build on this forum.

I could not get the 3 iMac G4 USB ports to work right, due to cross-talk. I think they share a common ground and/or 5V supply. On my 2 iMac G5 projects (done after the G4 builds) I managed to carefully cut the traces between the existing USB ports and successfully isolate each port. I think in hindsight this may be possible on the G4 as well. Once the common connectivity between the 3 ports is severed, they work individually as needed, and its just a process of soldering 4 wires to the traces of each USB port.

You'll save yourself some headache with mounting your own USB ports if you can get this work, I'd say its probably worth a try while you still have the original ports in place on the G4 logic board.


Keep the photos coming. Good Luck!


Ersterhernd

 

[hinsight4]

I have followed DremelJunkie's guide to exposing the LDMS and inverter cables so that all the original pins are usable to hook up the Molex Part No 74320-4004 DVI connector that I'm waiting on in the mail.

I ordered it from Mouser electronics: http://www.mouser.com/ProductDetail/Molex/74320-4004/?qs=x6EjVpvqMVPMh%2b55MERPvQ==

I need to find pinout guides on the 15" model since most of what I've seen online is for the 17" model.

Additionally - anyone know why all of the images in DremelJunkie's guide aren't working?

http://www.dremeljunkie.com/2011/08/guide-step-by-step-17-imac-g4-tmds-to.html

 

[InsaneCultist]

Anyone know why all of the images in DremelJunkie's guide aren't working?

http://www.dremeljunkie.com/2011/08/guide-step-by-step-17-imac-g4-tmds-to.html

I think his image hosting has been removed, but I found a simple solution using Wayback:

HERE

Good luck!
-IC

 

[hinsight4]

I think his image hosting has been removed, but I found a simple solution using Wayback:

HERE

Good luck!
-IC

Thanks, much better!

 

[hinsight4]

I'll be giving this pinout for the 15" a try (found on MacRumors buried a bit: http://forums.macrumors.com/showpost.php?p=9950054&postcount=207).

PicoPSU and several other parts are arriving today, I'll be posting a total parts list later on of what exactly what went on in this build.

Hope to put in the new Noctura fan and PSU this evening. Molex DVI connector won't arrive until next week

 

[hinsight4]

Amazon delivered quite a few parts this evening, so went ahead and finished cleaning out the top of the dome with some q-tips & alcohol before putting in a new low profile premium fan.

Fan didn't quite fit in the housing like I wanted, so I ended up doing a few things.

1. Cut the silicone steppers in half so they did not protrude through the hole in the fan as much
2. Used my dremel to cut small section out of iMac fan housing (the removable plastic part) so that the fan fit in as required
3. Then just installed the fan as normal and with the silicone steps, everything fit perfectly.