Troubleshooting Random Reboots

[bfreshour]

I'm having issues with my PC randomly rebooting. I've tested the memory using memtest86+ overnight and everything was fine. I can also run benchmarks such as Orthos or Prime95 for long periods of time without crashes. My system is not overclocked.

Thinking maybe my windows installation was fubar'ed (I had changed graphics cards from Nvidia to ATI), I rebuilt my system. Now, in addition to the reboots, my monitor will not power off. The display goes blank whenever it's told to go off, but it never enters power saving mode.

I've disabled automatic restarting, and have never seen a blue screen, it just boots without displaying anything. I'm at my wits end and have no idea how to troubleshoot from here on out...

My thinking is either power supply or motherboard at this point...

Any ideas?

 

[richc46]

If the random reboot does not happen too infrequently, you can try to work in safe mode. and see if it happens.

You can also work with a clean boot

How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7


Do not dismiss the two most likely suspects overheating, this could be bad

or maybe a virus. Run your antivirus.

Just a wild guess, overheating may be the most likely, But in the final analysis may prove to be some other cause.

 

[bfreshour]

Like I said, I've benchmarked and checked temperatures and they never top 55C. This is with an aftermarket cooler on an i5 750. I'm going to try a clean boot I guess...