Screen and sound occasionally crash

Hello,

Every now and then, while I'm running a 3D game, my monitor suddenly displays white lines, and my audio crashes.

Here's an image of the screen:

http://img.photobucket.com/albums/ [...] screen.jpg

Roughly 10 seconds after my monitor and audio crash, my monitor loses its signal. During the entire ordeal, my computer continues to run as if it's operating normally.

Here are my specs:

Athlon 64 x2 4600+
Windows XP x64
3 GB RAM
Radeon x850 xt
ASUS A8N-SLI deluxe
MGE 500w PSU
150 GB HD

These crashes occur anywhere from less than once a week, to more than once a day, and *only* when I'm running a 3D game, or anything else that's graphically intensive. A reboot of the system always gets me back up and running.

I'd venture to say my video card may be overheating, but then again, my sound crashes as well. I really don't know what the culprit could be.

Anything that could shed some light into this situation would be appreciated.

Thanks,

--Littlun

I get this about every 2-3 months. I pull the side and blow the dust out real good. My temps drop and the problem is solve till it starts overheating again. I also had the vid fan stop working one time, replaced it and back to normal. Also had to replace the compound on a vidcard one time to bring down the temps. I would proably start with the dust and if that doesnt help, check the other things.