Sudden computer shutdowns

I have an Asus p4p800-e deluxe motherboard, 2.8 gigs of ram, dual core processors Intel/Pentium dual core processors (3.20 Ghz) and a new GeForce 6200 LE video card.

My problems began on my old ATI Radeon X800 video card. Artifacts would occasionally come up with heat. It seemed to be resolved when I placed a fan next to it and moved it to a cooler location, but about a week later the artifacts came back and stayed for good. The computer would also shutdown randomly when I was playing a game - and I don't mean "Windows is now shutting down...". Just a nanosecond and boom.

The artifacts issue was resolved by my new video card. But the random shutdowns persist. I don't think it is overheating because I can run it on a game for hours on end without issue. I can let it cool overnight, turn it on in the morning, and it shuts down. I can play it in the warm summer afternoons for hours on end and it doesn't flinch. Temperature does not effect these random events.

I added 2 gigs of ram recently, but the timing doesn't seem right for the ram to be bad.

It may be a power supply issue, but I don't want to splurge hundreds of dollars if it is not going to fix it. Plus, the computer has no trouble turning back on after sudden shutdowns, which contradicts most power supply issues.

Any advice or comments would be greatly appreciated. Thanks for reading my post.

Is there an application to check PC temperatures or do I need to buy some fancy thermometer doohickey?

He has an Asus board, I'd use PC probe. From what he wrote however, I doubt its a temp issue.

Odd, as I find it works better then speedfan. Or at least the values are assigned correctly.

I have this EXACT same problem... did you ever manage to find out what the problem was?

You probably do need a fan on thet GPU. IIRC those X800s ran HOT.

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