I left my computer running today (as I usually do) and when I came back about 3 hours later, everything was off. I tried turning it back on, and my computers fans and case lights will turn on, but nothing is sent to the monitor (the light stays yellow) and there's no beeping as there usually is when the computer is booting up. Does anyone know what the problem would be? I tried different sticks of RAM and still won't. A week or two ago my CPU was running a little warm so I took out the heatsink and fan and cleaned it with canned air and put it back in and has been running cool since. Could it have something to do with that?

For the record, my specs are:
Nvidia 6800 Video card
Intel 3.0 GHz processor (Dual core)
1 GB RAM
120 Western Digital Hard Drive

I'm currently thinking its the board.. but I don't know. Any help at all would be much appreciated.

Thanks.

When you cleaned the heatsink did you take some of the old glue off that connects the heatsink to the processor? If it lost contact with the heatsink from lack of glue you could have blown out the processor.

I did get some of the thermal paste off of the CPU.. but there was still a coating on it. Just dusted it enough to get some of the dust off and some of the paste did come off, but it should be fine still, shouldn't it?

Also, I've been trying to figure out what it is, and now it won't even turn on at all most of the time now. Could it be the PSU? Or could it still be doing that because of a blown processor?

The worst part is I was just about to sell this one to build a new computer. Argh.

Anyway, thanks for the help so far.