PC Won't Start

[mycomputersucks]

Im going to try to give the most information as I can. Last night, I left my pc on. While I was in bed, it turned off. I looked and nothing smelled burned. I noticed when the PSU was on, the light on my motherboard turned on. I tried to turn it on, but all I heard was a faint click of power, then nothing happened. I don't have a speaker on my motherboard, either. I assumed it was a cpu problem, so i cleaned off what was left of the thermal compound and applied a fresh coat. That didn't work. I tried changing the 4 pin adapter, that didn't work. I replaced the CMOS battery, that didn't work. I don't have a PSU tester, and i really don't want to spend 15 dollars then find out the psu isn't the problem. What else can I do?

 

[mycomputersucks]

UPDATE: When I have the ATX12V (4 Pin CPU) plugged in, it shorts out, but when I unplug it, it boots fine, but of course no CPU power. What can I do to fix this?

 

[mycomputersucks]

BUMP: This is getting out of hand. I've gone 4 days without a working computer because no one bothers to reply.

 

[SkyBill40]

It's likely your PSU is dead. If it tries to power on for a second and immediately shuts off, it's toast. This would be especially so if you've not made any physical connection changes to your power configuration.