PMG5 crashes while running Thermal Calibration

[iamMacPerson]

So I just picked up a free OG dual 2GHz G5 today and have been working on it most of the day. I have come across an issue though. Whenever I load an app or anything, the system revs the fans like crazy then they settle back down. Having had this issue before, I repasted the CPUs and went to run the Thermal Calibration test from ASD 2.5.8.

Everything is fine until about 15 mins in when it crashes. And I don’t mean it locks up; The computer completely hard powers off. It comes right back on and I do not have this issue while booted into Mac OS X but what could be causing this crash? It also has not made a bit of difference as the fans continue to rev. I’m thinking it may have a problem writing the new thermal calibration into NVRAM or wherever it’s stored.

 

[FrancoisC]

Try to check the voltage of the NVRAM battery maybe? If that's the source of your problem it's an easy fix Otherwise maybe faulty PSU that only trips when system is at 100% load, which I THINK (really not sure here) that is what happens during thermal calibration.

 

[iamMacPerson]

Try to check the voltage of the NVRAM battery maybe? If that's the source of your problem it's an easy fix Otherwise maybe faulty PSU that only trips when system is at 100% load, which I THINK (really not sure here) that is what happens during thermal calibration.

Already replaced the battery sadly. Maybe I’ll try hitting it with a 100% load in the OS and see what happens.
[doublepost=1565494966][/doublepost]Hitting it at 100% load, all had been fine for about 5 mins. Here’s something interesting though: the CPU0/CPUA’s fans are running much faster than CPU1/CPUB’s. Plus the air from CPU1 is much hotter (as expected). Could it be an issue with CPU0? That’s the chip that fails calibration.

 

[1042686]

Run just one cpu - the cpu in question & see if it works. If it’s dead, you’ll know pretty quick.