Computer keeps turning off, why?

[bandit390]

My computer keeps turning off after being on for a couple hours. Its like the power going out, just cuts right off, no warning etc.. Nothing is overlcocked and the only thing I have changed is evga's 7900gtx ( n570) with the new 7900gtx ( N571)

Everytime it cuts off I have to take the mb battery out, put back in and it will come on for a while. Just a little while ago, even that didn't do it. I then changed my 2x512mb memory to the other 2 slots and now it finally came back on.

This has been going for a week. But also started the same time I put in the new 7900gtx. So could it be the video card, memory, ........., ...........?

What else is there to check?

 

[Its_me]

It might be your power supply i had a similar problem with my old computer. After it just being on for a few hours it would just stop freeze go to a blue screen. Then when i reset it it would just get stuck at the bios screen. I just changed the power supply and i havent seen the problem since

 

[heero884]

My computer keeps turning off after being on for a couple hours. Its like the power going out, just cuts right off, no warning etc.. Nothing is overlcocked and the only thing I have changed is evga's 7900gtx ( n570) with the new 7900gtx ( N571)

Everytime it cuts off I have to take the mb battery out, put back in and it will come on for a while. Just a little while ago, even that didn't do it. I then changed my 2x512mb memory to the other 2 slots and now it finally came back on.

This has been going for a week. But also started the same time I put in the new 7900gtx. So could it be the video card, memory, ........., ...........?

What else is there to check?

i would check the power supply first. if that checks out ok i would go into the bios and reset the settings to default. then i would loosen the timings of the ram further. afterwards i would run mem test 86 to test out the ram. if the ram tests fine then i would try running prime95 while monitoring system temperature to check the cpu for stability.

guide for testing psu:
http://www.driverheaven.net/guides/testingPSU/

program for testing memory:
http://www.memtest86.com/

program to check cpu stability:
http://www.mersenne.org/freesoft.htm

program to monitor cpu temp:
http://www.almico.com/speedfan.php