So, just under 6 months ago I built a new rig with a Sapphire Radeon 6950 2GB graphics card. For the last 3 days it either doesn't display any video at all (though the system POSTs and otherwise starts up just fine) r everything starts up fine but within half an hour the video cuts out. This happens whether the system is idle, playing a video or being stressed with a game.
It's under warranty (though I've heard Sapphire is awful for customer support, and I've been given an estimate of 6-8 weeks for a replacement. So I'm looking for any second opinions. It seems like the card is done but I'm willing to be proven wrong for sure.
Asus Formula IV MoBo
AMD Phenom II x6 1090T
8GB G.Skill Ripjaws RAM
Windows 7 64-bit
Do you have another video card or onboard video to try?
Try reseating the graphics card into the PCIe slot, make sure it's all the way in properly. Use a little force if you have to but not too much.
Also make sure that the power cord is attached to the video card firmly (sometimes it get loose if moving anything inside your case)
make sure that your video cable is all the way in. (and that no pins are bent in any way)
last it could be heat related, check the card's cooling (usually a fan) that its working properly.