I'm having some troubles with my computer. Yesterday I had a bluescreen about some graphic driver dll and couldn't boot the computer back. I swapped my graphic card for a backup and could boot the computer again. This morning things fell apart pretty quickly, the two graphic card weren't working anymore and the screen went black right after the "Starting Windows" animation. I tried to format but the problem persisted with the two GPUs, I just tried a backup PSU thinking it may be the problem but it still happen. Now I can use windows if I have no graphics driver (So windows use the generics ones) or if I use the onboard intel graphics but as soon as I plug a GPU back, I get blackscreens right after the boot animation.
I also tried plugging the GPUs in the second PCI Express slot without any effect. I'm starting to think it may be a motherboard problem but I would prefer to be sure before starting a RMA. Is there any tests I could do to narrow my problem down?
Informations about the computer :
Windows 7 64 bits
i7 3770 with Asus P8Z77 motherboard
First GPU GTX 470 and the backup one is a GTS 250
First PSU was 910Watts and the backup one was a 650Watts
Edit : Forgot to mention I did try an older driver in cas the latest was causing problems. No change