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PowerMac G5 with fan problems. Is my diagnosis correct?

877 Views 13 Replies Latest reply: Dec 2, 2012 4:56 PM by aronfromtoledo RSS
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Nov 29, 2012 12:35 PM

I was hoping that someone could confirm my diagnosis of problems on my Powermac G5 2.0 GHz dual. It's one of the original ones (bought in May 2004). For a while now I've been having problems with the computer not waking from sleep, fans at full speed, shutting down unexpectedly, etc. I got hold of an ASD 2.5.7 disk and ran the tests. Everything passed, so I tried a thermal calibration (I hadn't changed CPUs, but I have had them out for cleaning a few times). The calibration failed with the messages:



Calibration start CPU0

ERROR CPU0 - Processor 0 ID EEPROM checksum error

Replace Processor CPU0



Calibration start CPU1

ERROR CPU0 - Processor 0 ID EEPROM checksum error

Replace Processor CPU0



so it appeared that Processor CPU0 (the upper one, I believe) is bad.



I opened the machine, and switched Processor places, then tried the calibration again. This time CPU0 calibrated successfully, but CPU1 (which was CPU0 on the first try) failed with the message:



ERROR CPU1 - Check that outer door is securely closed and recalibrate

Ambient Temp Sensor (IC2) is located on main logic board.



I was confused about that last, because it didn't say anything was wrong with the Ambient Temp Sensor.



I then switched Processors back to the original positions, and got the same Errors as the first test above (i.e., EEPROM checksum errors on CPU0).



I'm taking this to mean that the logic board is okay, but that one CPU (the original CPU0) is bad, so I need to replace it.



Does that sound right?



Thanks in advance for any help.






PowerMac, Mac OS X (10.5.8), original PowerMac G5 2.0 GHz dual


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