I did nothing! I was just doing normal stuff online when the computer freezes on me. I first tried ctrl+alt+del more than once, but it didn't do anything. So I pushed the reset button. The screen goes black, but the computer doesn't beep, and nothing appears on screen. There is power, the fans are on and the lights come on on the disc drives. the light blinks on the monitor, but the computer won't do anything. The power button doesn't do anything, and when I switched it off w/ the surge protector and switced it back on again it still doesn't beep or POST. This happened before about two weeks ago and it came back after I unplugged it and plugged it in again. But this time that didn't work. I even waited for over an hour to see if something needed to cool down or something, but it still didn't work. The only new thing I've done recently was change the threshold for the cpu temp in the temperature monitoring program that came w/ the motherboard. I changed the threshold from 54c to 56c. (still well below the limits)

Are there any beeps when you turn on the machine? Are the fans running? Your Power Supply may be dead... Soylent Green is PEOPLE!!!

Disconnect all the drives and see if it'll at least give the posting screen.

No beeps. But the fans ARE running, so I know it's getting power...

I took another look inside and noticed that three capacitors that sit right next to the processor are blown. Might that be the cause? If so, what is salvageable? Is it possible to replace just the capacitors? or just the motherboard? (while keeping the ram & processor)

I'm sure the capacitors can be replaced but it may not be worthwhile. Even assuming you're adept at soldering it may not be easy to do. And you don't know why they blew in the first place. I think I'd look into a new motherboard. The other hardware may still be OK but the PS may be questionable.

Is this a Dell 260/270 by any chance? If so, those are known to have bad capacitors. You'll need to replace the MOBO. Hopefully, it's still under warranty. Soylent Green is PEOPLE!!!