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G5 Power supply out...now what?
Posted by: OleLila on 2018-10-17 11:50:36 I spent the morning taking apart a 2.3 ghz DC G5 power mac this morning. It made no noises or lights what so ever and the power supply made no click when plugged into the wall. After searching online, I thought I could at least check the fuse. I can see one end of it with the other covered in grey glue and it is not accessible without tearing down the power supply through the goop. Not sure how or if to proceed. .
Posted by: 360alaska on 2018-10-17 12:33:10 To me it sounds like you don't yet know whether it is the power supply or logic board. The best thing to do is bench test the power supply: In order to manually start up any PSU, you just ground the green wire. Here's the pinout for the G5 PSU- Power Supply P1 Connector Pin# Signal Color -- Pin# Signal Color 1 +5Vstb Purple -- 13 GND Black 2 GND Black -- 14 Power ON Green 3 FANtach White/Yellow -- 15 GND Black 4 GND Black --16 Reserved 5 Reserved --17 GND Black 6 GND Black - 18 RTNaud(GND) Black 7 +12Vaud (12V2) Yellow - 19 GND Black 8 GND Black -- 20 +5V sense Red 9 +3.3V sense Orange -- 21 GND Black 10 GND Black -- 22 -12V Blue 11 GND Black -- 23 GND Black 12 Reserved -- 24 Reserved Power Supply P2 Connector Pin# Signal Color -- Pin# Signal Color 1 +3.3V Orange -- 9 +5V Red 2 +3.3V Orange -- 10 +5V Red 3 +3.3V Orange -- 11 +5V Red 4 +3.3V Orange -- 12 +12V3 Yellow 5 Reserve -- 13 +12V3 Yellow 6 +12Vfan Yellow -- 14 +12V1 Yellow 7 +12Vfan(12V2) Yellow -- 15 +12V1 Yellow 8 +25V White -- 16 RTNfan(GND) Black Power Supply P3 Connector Pin# Signal Color -- Pin# Signal Color 1 +5V Red -- 5 +5V Red 2 GND Black -- 6 GND Black 3 GND Black -- 7 GND Black 4 12V2 Yellow -- 8 +12V2 Yellow Source: https://discussions.apple.com/thread/1288831
Posted by: OleLila on 2018-10-17 16:09:06 I guess this is a 750 or 1000 watt supply....these are the only two connectors....on P2 pins 6 and 7 are green...I jumped them to black (only one at a time, not both at the same time) and nothing happened
Posted by: 360alaska on 2018-10-17 20:56:55 Yep, your fuse is probably bad then, it's a 10a 250v, that stuff you call goop is likely just RTV or hot glue and can be removed with a pick. Here is something else I found: http://damntechnology.blogspot.com/2009/02/rebuilding-powermac-g5-power-supply.html
Posted by: OleLila on 2018-10-30 01:12:06 Well....not the fuse anyway.
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