Mac pro power problem

[cliff77v]

Looking for some help with a 2010 4.1 that shuts off. If it sits overnight, it will startup and run for up to a couple of minutes, with a successful login and screen population, but then suddenly switch off. After that, it won't respond to the button at all. Wait a few hours, same cycle. Tried a restart, replaced bios battery, and today tried a new power supply. Same issue. I'd upgraded to a better graphics card, which I thought might have taken out the supply, so I put back my original. Same issue.

Wondering if there might be something else I could try before taking it in?

Thanks for any suggestions.
Cliff

 

[pigoo3]

Hey there Cliff sorry to hear about the Mac Pro troubles. Geez...you tried a many of the things I would have suspected already (power supply, video card, PRAM battery). I don't really think it could be bad RAM...but you could try pulling all the RAM...then only installing minimal RAM. Then boot & reboot with different RAM modules to see if any single module or pair of RAM modules maintains stability.

HTH,

- Nick

 

[lclev]

In addition to what Nick said there are diagnostic lights on the logic board. Each memory stick will have a diagnostic light. To diagnose memory issues, start up the computer and check the diagnostic memory LEDs. An illuminated, red LED indicates its associated DIMM may be poorly seated or failed.

Have you tried resetting the SMC and PRAM? It won't hurt to do it. Also this could also be a dried out thermal paste issue. The thermal paste on the CPUs can get dried out and cause overheating.

Lisa