Computer Turns off at Random

[Taiidan]

I am having problems with this machine turning off at random, and I am looking to see if anyone else has had a similar problem, or has any insight into the problem. Just trying to get a better idea whats going on before I start replacing parts.

Asus P5N32e Sli Plus
3x1GB Mushkin DDR2 800
XFX GeForce 7900GS
WD Caviar 160GB HD
Intel E8600 Wolfdale

A while back I started getting an error code from the BIOS on POST - 1 long beep and 3 shorts, which I understand to mean "Video Adapter Failure", and I assume means video card. To troubleshoot the issue, I moved the video card to another PCIe slot, which stopped the error beeps, but the machine still wouldn't POST. It just sat there with a blank screen and all the fans spinning at top speed. So, I began pulling out ram sticks, and it booted after the first one came out. So, I tried putting another stick in it's slot, and the machine still booted, so I assumed the ram was bad.

Since then, the machine usually boots (though I have gotten the "Video Adapter Error" bios beep once, it started fine on next try). However, it will simply stop at random. Sometimes under load, sometimes not. It doesn't shut down, it doesn't get BSOD, it just stops. The screen goes black, but power to the machine does not stop - all the fans spin up to top speed and sit there, for as long as I let them.

I have tried running memory tests, but the machine has always quit by the time I get up or home from work. My plan from here was to take out all the ram except one stick, wait for it to stop, and then put a different stick in, in hopes of finding out if its bad ram.

After doing some reading, I am starting to suspect a failing power supply. Is there any way to test that? Or, are there any good ways to tell if it is the vid card or motherboard, without having replacements?

Thanks for your help.

 

[BoBBYI986]

sounds like graphics card to me, if it was power supply unit your machine would most likely shutdown completely. I've had a similar problem before what I had to do was reseat my graphics card and use generic drivers. left it for 30 mins before updating to proper drivers.

 

[Taiidan]

Thanks for the response. I tried uninstalling the Nvidia drivers and just letting it sit running on the default Windows drivers, but it cut off again after just a couple hours. It probably is the video card, though I'll probably troubleshoot the ram a bit more, just because thats easy to do and I don't want to spend money on a new card if I don't *have* to.

Also, another bit of info that I meant to include in the first post - I don't think this is a heat problem because I have been running SpeedFan with logging on. After a cutoff, the last temps in the log are not incredibly high (70-80c), and there are higher values further up in the log. (Yes, the machine runs a bit hot - it only has stock heatsink, and that needs to be cleaned.)