Originally Posted by
Colamisu
Just so you know, this could very well be a RAM issue. I was swapping out RAM sticks in my other computer to test ones that I was pretty sure were bad, and I was stuck at a black screen before POST with nothing on all except the one known good stick. Video card, HDD, and all of that spun up, but no display. A RAM issue would also cause the restarts. Did you happen to get a BSOD when your computer shut down?
As long as you're making boot disks to check hardware, you may as well run Memtest86 as well. Google it.