Weird Tiling Images, kinda like artifacts, but not

[hamalnamal]

Okay so my wtf error of the month.

I'm trying to fix an oldish desktop with an ht2000 MCP61PM-MH motherboard that has integrated video (NVIDIA GeForce 6150SE nForce 430 w/ 256Mb RAM). OS doesn't matter as this error happened both in Win7 and Ubuntu 10.04.

So what happens is randomly, and really for no apparent reason because I haven't been able to force the error, a piece of the screen gets tiled across the entire thing. Seems to be like a 10px x 100px piece or so. And then it just stays like that and I have to hold the power button to get it to power down.

I've tried using an old video card that I had lying around, but the computer won't even acknowledge its existence. I unplugged everything and plugged it all back in. I tested in the RAM with memtest86+, although not the Video RAM as I don't have a utility for that (I use the Ultimate Boot CD). I tried plugging in a different, more powerful PSU, which it then got angry at me for doing and just caused more problems.

My thoughts are something to do with the integrated video or PSU (it's only 250W). But I really have no idea.

Any Thoughts?

 

[Theory5]

Sounds like the video card to me. You said you are using the integrated one? Does the motherboard have any burnt peices or anything missing or out of place?