URGENT!! Need help troubleshooting video problems

I need a quick sanity check here. I set up a PC withAbit An8 boardAthlon 64 3500+1GB Patriot DDR400Sapphire Radeon x700Pro 256MBAntec Case with 350w Smart Power PSUAnyway, I built the system and it ran fine during setup for about 6 hours. Then all the sudden the video goes all screwy and just displays randomly colored pixels everywhere. I tried most of the standard troubleshooting (I am on the road for the holidays so don't have a spare PSU or GPU to test) and can't seem to isolate the problem. It's not a driver problem because the monitor won't even show POST correctly (the monitor is fine). I cleared CMOS, it doesn't seem to be a BIOS problem, as the PC seems to boot though I can't see for sure. The POST Message Center does seem to be picking up a video error (though not a fatal one).

I am thinking it is either the PSU or a bad card that needs RMA'd. I will aprreciate all the help I can get.

I also posted this to the Graphics cards section cause I need urgent help before I return home. Thanks in advance.