When I woke up this morning, I noticed that there had been a power outage while I slept. When I went to turn on my main rig, all the fans started up, but I didn't even get a beep code. The last time this happened to me, it was because the motherboard had failed.
I've had this machine for about two years, so it was time for me to upgrade anyway. My new machine should arrive in about a week, but I'm going to be on my Mac Mini for the next week or so.
These things happen.