Need Help: iMac + Raspberry Pi = PiMac

Jan 10, 2017
Hi All,

I was recently given an old iMac 20" (2133 model) to see if I could fix it. There was a logic board failure, so I figured it was not worth the trouble/money to replace it, given its age and limited performance. My wife has a Macbook Air and I am not a big fan of OSX either. I do love the body of the iMac and want to re-purpose it and some of the internal hardware. My plan is to wedge in a Rasberry Pi 3 and keep it as a simple low-power browsing desktop in the kitchen. For that, I need a little help on the wiring.

Hardware I want to reuse:

Power Supply
The stock PSU is still in working order. I have found a basic pinout diagram from, though the comments say it might be off. Anyone more familiar with the pinout in this model?
The PCB says it provides both 12Vm+ and 12Vs+, what is the difference?
Seems like 12V is the only output here. In order to drop the voltage to 5V that is required by the RPi3, I will simply gut a 2.5A USB car charger I have laying around.

LCD Panel
I have ordered an LCD controller board (Here). This should allow me to plug the LCD into the RPi with the HDMI connector and pull the 12V power from the PSU directly.

External Ports
I guess the simplest way is to cut the PCB board and solder into the port contacts? I don't have a dremel, so I will try to hacksaw it into a manageable size.

The two speakers both have 4 wires. Anyone know the pinout? I plan to rewire them to a 3.5mm jack. I will not really use it for audio, as there is a Bose dock next to it with far better sound. So this is a low priority.

I probably do no need these for a simple RPi, as it barely generates any heat. But just in case I add a hard disk inside. Anyone familiar with the wiring and adjusting fan speeds?

Mar 8, 2017
I recently acquired an iMac g5 17” ALS which had blown/leaky capacitors, I think for the amount of work required to repair, I had this same idea... gut it and use it as a retropie emulator. I have basically no experience with hardware modding (wire splicing or otherwise), but I think this would be a fun little project to learn. I will add updates if I ever decide to attempt this. Have you had any success?