Hello fellow Citizens,

Hoping someone can give me a bit of advice on this one. Just got a Sapphire Tri-X R9 290X, running Win 7 64-bit Pro currently with a new 1000W PSU. Uninstalled the 7950's drivers, got everything connected in, hooked it up, installed the packaged drivers, and it worked for about five minutes before suddenly giving me "no signal". Since then, I've restarted countless times, tried power down, remove card, power up and down, reinsert card, power up process, updated BIOS from the motherboard manufacturer's automated updater (running Gigabyte GA-Z77X-UD3H F18 BIOS currently), tried clearing CMOS (though my BIOS immediately corrupted and restored itself from a backup image after that, so I'm not sure if that was successful). To top things off, when trying to access the BIOS interface before starting, All I get is the "Gigabyte UEFI DualBIOS" banner up top and absolutely nothing else, even after waiting several minutes. Motherboards shows a d5 boot error on the failed BIOS page, which is apparently memory-related, but if I leave it alone during boot everything loads up just fine. (memory is 2x4GB and 2x8GB Corsair) Also, I have seen the UEFI before using the exact same monitor. I can get a video signal from the MB HDMI port, but not the 290X's, though if I start in one I have to power down in order to switch to the other.

Anyone got some recommendations on what to do from here? I'm pretty much at my wit's end with this thing. -_-