I have remounted the heatsink to no avail. Do you think this could be a VRAM issue? I've tried running Memtest86+ to establish whether either of my RAM sticks is faulty, however the computer craps out before the test can be completed. Interestingly Memtest86+ lists my RAM settings as (SETTINGS RAM: 665mhz/CAS 6-6-6-20/Single Channel) but my RAM is Corsair 8GB DDR3 1600MHz Vengeance Memory, - PC3-12800
- CL9 ( 9-9-9-24 ) 1.5V.