PC won't boot, nVidia 680i giving solid beep

I woke up this morning to find my PC completely frozen at the re-login screen. I thought nothing of it, forced it to shut down and went to work.

When I got home this evening, I turned it on but it's not booting. The fans spin for about 10 seconds, then I get a single blank cursor in the upper left of the screen and I'm getting a solid tone from the tower. I'm not sure if the tone is from the motherboard or the video card.

I'm already researching this and am going to check my hardware momentarily; I'm just posting this in case someone happens to have encountered this problem before and/or has a solution.

Specs:
nVidia 680i mobo
EVGA 8800GTS video card
2GB OCZ PC-800 DDR2 RAM
Core2Duo 2.6Ghz overclocked to 3.5Ghz

Thanks in advance for any help or insight.

*cringes*

Has run smooth and cool since the day I installed it

The entire computer or just the things with built-in thermostats on them ?

If I'm reading that right you've got a really hefty over-clock going there. Even if your CPU is taking it in stride, something on the mobo that doesn't have a thermostat might have been crying silently all this time.

Forgot about this topic after creating it, whoops.

I opened 'er up and found one of extra PCI cover plates laying on the mobo; it could have been shorting something out. It probably came loose when I was transporting the thing a couple of weeks ago.

Everything else seemed securely in place and it's back to running fine now, so I'm not sure what it was.

In any case, I'm buying a new external hard drive to make sure my backups are up to date