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Fendbass22
Mar 7, 2007, 08:13 PM
Hello. Im just getting into the Mac world. I picked up a G4 2x533 and it has a dead PSU. I took it apart to find some dark/black solder marks and removed the resister that it was connected to. It doesn't look healthy and only had a value of about 100ohms.

The color bands were really hard to read cause so charred. Im pretty sure it was red/white/red/gold or red/yellow/red/gold. So 2400 or 2900ohms. I was wondering if anyone had a schematic I could verify this with.

Any other help would be great. I knew the PSU was bad cause there was nothing on the +28v wire.



Bobdude161
Mar 7, 2007, 11:14 PM
http://www.outofspec.com/frankenmac/wire.shtml

Fendbass22
Mar 8, 2007, 03:47 AM
Thanks for the help. That gives me another alternative if I can't fix this one. Do you know of any site that will have the circuit schematics within the PSU? I need to find that resistor value. Thanks again.

Bobdude161
Mar 8, 2007, 05:58 AM
Thanks for the help. That gives me another alternative if I can't fix this one. Do you know of any site that will have the circuit schematics within the PSU? I need to find that resistor value. Thanks again.

Can't find a site with schematics for the internals. :o Do you have a volt meter? Maybe that can solve things.

EDIT: NVM, saw that you already checked it

Bobdude161
Mar 8, 2007, 06:04 AM
Actually now that I think about it. Go to MacMod's forums. They have more knowledgeable people there on hardware, especially the difficult specific parts. They always helped me when no one in MR was smart enough to answer my question (just like me in this situation). Try this section in their forum link (http://www.macmod.com/component/option,com_smf/Itemid,222/board,24.0)

Fendbass22
Mar 8, 2007, 05:53 PM
I bought both resistor values at work today. Should have them by Saturday. I will use the higher resistor value first and test the output voltage. I'll let you know how it goes.