I think my HD 5770 memory is getting a temp causing the monitor to switch off after Windows 7 welcome screen. I already tried it in other pcs and got the same problem. After removing the card pc is just running fine. But no games here after . Ive been using the card for past say 2 years. Its was just fine since 2 days. Banged my head everywhere to get a solution but of no avail. Any help regarding the problem apart from purchasing a new graphics card would ease the things a bit.