Hokay, I've got a duo core 3ghz pcu, 2 gigs corsair 800mghz ram, 512 video 9800 gtx pniy? I think, 650 watt psu on an asus p5n32-e sli. Worked fine for probably 1.5 years, (built the system myself) recently screen will either flash once and screen will freeze, or screen will bug out and flash a combination of blue and whatever was on the screen when it froze. When it happens is completely random, between first five seceonds of startup, but usually no longer than 10 mins. (lasted for an hour once in the last 15 startups) I figured it was either the psu or the video card, more likely the psu as it was cheap, and the video card is pretty bad ***. Since this problem has begun I have given everything a really thorough cleaning with compressed air. it should also be noted that there are no bios beeps asides from the single startup tone, and that I do not believe it to be related to the hdd or os, as the issue has happened to me while in bios. Please help as taking in to the shop would spell certain defeat for me. thanks TRIZ.