Won't even boot the bios. Progrssivly worsening problem.

Asus P5N72-T motherboard, q6600 processor, ect.... dual 8800 ultra vid cards running sli.

It was running perfectly until a couple of weeks ago. It started hanging up on boot up at the bios splash screen. It would also go to the post bios screen. Sometimes it wouldn't show anything on the screen and the monitor wouldn't even wake up. Some times it would boot normally.This evening it booted to the windows safe mode window (I am running vista 64bit) and I hit start normally. It then did nothing. The light on the monitor went to yellow, no attempt at anything.

I have pulled video cards, tried booting with one video card, reset the bios, pulled the bios battery, everything I know to do. It won't even go to bios- there are no beeps or anything like its trying to go to bios.

I haven't pulled the memory yet. Anyother ideas?

I believe I did flash it last year.

sounds like a corrupted bios, or your Mobo biting the dust.

If you consider flashing your Bios do beware, there is a fairly high chance that it will disrupt or break the software completely. Standard rule of thumb is "never flash from an OS" use a usb flashing tool, or floppy (dvd possible aswell)

Well, I've tried removing the video cards, tried each one in each of PCI-E slots. I've removed the memory completely, tried each stick individually. Nothing even brings up the bios splash screen let alone anything else.

The problem started gradually- At first I had to boot twice in order for it to complete, later it would hang on the splash screen- then do a post bios screen. The thing I recalled last night after I posted was I got a BSOD on my second to last boot up & then the final time was just the boot windowa in safe mode screen.