Power Supply for 20" g5 iMac

Question

I have a first gen 20" G5 iMac, but it needs a power supply. Can I use a power supply from a first gen 17" model. I actually have one of those available. Thanks.

Answer 1

Hey Bennett,
Well power wise the two supplies are very similar.
The 20":
+3.3 V 4A
+5.1 V 9.8A
+12.0 V 6.5A
+24.0 V or +20.0Vs 0.4A
+5.1 Vsb 1.5 A
The 17":
+3.3 V 3.1A
+5.1 V 9.6A
+12.0 V 9.2A
+24.0 Vsb 0.33A
+5.1 Vsb 1.5 A
However in terms of an exact replacement, physically the differences between the two is the placement of the AC inlet socket. In the 20" it's near the right edge. In the 17" it's ~ 1" to the Left. So the locking tab indent and the socket are in the wrong place.
I think the pinouts are identical so you should be able to electrically test the 20" but you'll never get the back on without major mods.
I'd refer to Jim's site:
http://jimwarholic.com/2008/11/apple-imac-g5-power-supply-issues-and.php
He's very responsive and knowledgeable about these power supplies and you could ask him about the swap.
There are also ATX hacks to replace the 20" supply (there are many links and pics on Jim's site) and I've done that and have used the hacked ATX supplies to verify that I have a PSU problem. I've never gotten the sleep function to work properly tho'.
Richard
Message was edited by: spudnuty