Signs of a bad motherboard or CPU card?
I recently got a used PM G5 (dual 2.0GHz), built in late 2004. From the seller I bought it from on eBay, he stated that it would, after running a bit, just freeze up and only a hard reboot (ie. pressing the power button) would restore control. I'd like to repair this box and thought, since the CPU heatsink covers were missing when I bought it, that the CPUs had been replaced since the original date of assembly and that the problem was that the thermal calibration test had not been run since the CPUs were installed. Hence I had an Apple tech run the thermal calibration test from the diagnostic CDROM. The Apple tech said the thermal calibrarion tests were fine, as were the other diagnostic tests he ran.
The first week I had it, the box would boot up and be usable for maybe a day or so, then just freeze up (ie. no response from keyboard or mouse). Now, right after power on the box freezes. No message in the system.log . I was able to get a G5 version of Tiger installed on a HD I put in the box and added the app TemperatureMonitor to Tiger. The CPU temps at freeze up are only 30 deg. C. not 65-70 C. Hence the box doesn't seem to be overheating at all when it freezes. Within minutes now of power on and freeze-up, the fans start blowing hard.
Are these symptoms an indication that the motherboard is bad, or is the CPU card itself bad? I haven't tried resetting NVRAM, or hit the PMU button on the motherboard yet.
Any tips or ideas would be greatly appreciated!!
Ed
PB G4, Mac OS X (10.4.11), PM G4 Dual 1.25, PM G4 Dual 867, OSX 10.2.8, OSX Server 10.2.8