PC Shuts down after 30-40 minutes of gameplay - Not overheating???

[rmaddock]

Hey all,

My PC, after 30-40 minutes of any game with a 3D element in it, shuts down. It never shuts down while being used normally (email, movies, internet), but consistently when gaming.

I noticed it while playing both Starcraft 2 and Civ5, but then I tested it with Civ4 (7 years old) and it STILL crashes.

I replaced by NVIDIA video card (8800GTS) with my ATI card - and it still crashes.

I thought about overheating, so I checked the temp. Neither the video card nor the CPU(s) go above 75*C.

I thought mad RAM, so did a 10 hour memtest - no errors.

Drivers are all up to date, as is Win7.

Any ideas?

Thanks.

Specs below:
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600)
Processor: Intel(R) Core(TM)2 Duo CPU E6850 @ 3.00GHz (2 CPUs), ~3.0GHz
Memory: 2048MB RAM
Card name: ATI Radeon HD 5700 Series
Motherboard: Abit IP35 Pro ATX

 

[jefe323]

you might want to check your psu. i had a similiar problem and it turned out that my psu was dying

 

[rmaddock]

any test I can run, besides getting a second PSU?

 

[jefe323]

this link has a couple of tests you can do: http://pcsupport.about.com/od/toolsofthetrade/f/powersupplytest.htm

or you can borrow a friends/family members psu and see if the problem persists in your system

 

[rmaddock]

Best answer selected by rmaddock.