I have z77 ASrock OC formula, 3770k@5ghz and 290x lightning. I got faulty 290x sapphire, it has random blackscreens with elpida. I tested it and it was true, random blackscreens even in crossfire.I tested everything so there was nothing to lose. I decided to bake - 200 celsius degrees for 10 minutes. GPU looks well, no damaged visible, some almost faulty soldered places seems to be much better so I putted into my PC. PC started but no picture. I tested it again and nothing. What ever bb bad 290x. BUT then I put back my wonderfull 290x lightning(1150/6600) and black picture! I tested it again, reseteed bios, nothing helped... seems to be PCI-E controller any ideas how to fix it? Possible to change some IC on mobo to make it works again?