I looked at that QFlash thing and it says there's some danger in doing that?If it was my pc, I would first update the bios, then try a different power supply (even if you have to borrow one from a friend). Are you sure they replaced the video card? I wouldn't think the replacement would be bad as well. I suppose you could try a different video card if you have access to one. All you can do is try different parts until it comes down to motherboard. No definitive way to make sure its the motherboard at this point.