After about four months with a total of hundreds of video errors (logged in Win7 event viewer) I get no image on my monitors. Swapped out video cards, same thing. Tried different PCIe slot, same thing. Swapped out memory. Unplugged a bunch of components in case PSU was failing, but no help. I don't hear a beep when the system starts up. All fans, lights, disc drives are powered and working. I'm totally stumped!
Asus P5Q Deluxe
Core 2 Q6600
Corsair 750W PSU
Saphire HD 6870
Thanks for the response! I haven't replaced the PSU or motherboard. Everything seems to be powered up with the PSU, including the fan on the graphics card. Hard drives, disc drives, cpu fan, motherboard power/reset lights, 5 case fans...Guess that means likely the motherboard. Replacing that would mean buying all new kit, really, since the LGA775 boards are kind of hard to come by. That would make sad. Thanks again.
Problem solved (just writing this for anyone else with future issues like this). It ended up being something with the MB or RAM. I put the RAM in different slots and also gently wiped it down with a cloth. I also popped the battery out of the motherboard and put it back in after a few moments. Not sure which one of these solved the problem, but now the system boots up just fine and the displays are working again. There was a ton of dust in the case - might have been a contributing factor.