Power Mac G5 Issues

[SuperKerem]

Hi,
My Quad G5 is having some issues. It runs fine normally, but yesterday I decided to run Geekbench on it just to see what it would score. But halfway through the test it would freeze completely and two red lights would appear through the front of the system. I try a couple more times and have found it either freezes or it randomly goes into sleep mode and resumes the test when the power button is pressed.
I decided to run the ASD (2.6.3) and selected the Thermal Calibration option because I thought the freezing could be due to the system overheating. (Although the temps look fine in iStat)
However, a few seconds after starting the calibration, the G5 would again freeze with the two red lights.
I restarted it again and loaded up the ASD yet once more. All other diagnostics run ok as far as I can tell, but the Thermal Calibration causes a freeze.

As I have mentioned, the G5 runs perfectly fine with normal use but freezes when running a Geekbench or Thermal Calibration, I only discovered the issue yesterday! Could this be a sign of future problems?

 

[SuperKerem]

Anyone know what's going on?

 

[havokalien]

i would guess

Most common issue would be too much thermal paste or dried causing inadequate cooling. One it starts taxing the processor in question it freezes. Also the processor itself could be going bad.

 

[Hrududu]

You've got access to the ASD disk obviously, have you thought to run the diagnostics? Thats going to be far more helpful than a bunch of folks here making guesses.

 

[fuzzface]

I would suggest reading Heikki Lindholm's excellent writeup on the Quad's LCS.
The symptoms you describe (OVERTEMP & CHECKSTOP-LED becoming lit under heavy load?) sound to me like your LCS is no more providing sufficent cooling and probably needs an overhaul.

As Heikki states, I would also advise against running ASD's Thermal Calibration on an impaired LCS.

Here's the Link:

http://www.saunalahti.fi/~holindho/g5-quad-v1-lcs-repair.html


Cheers

Thomas

 

[SuperKerem]

Works after reseating RAM!

 

[SuperKerem]

Huh, I reseated the RAM and it works fine now! A RAM stick was only halfway in, maybe that caused the freezing.