PC Shutdown, problem unknown.

[zeroja]

Hi,
I've got a problem and was unable to solve it myself. In short - my PC won't start. It shuts down in a second or two after I push the button to start it. Sometimes it boots windows, but after some time it shuts down. It all started today, before there were no problems at all. That system was assembled a few weeks ago, worked great, and now I come home, start it and it won't start. I tried checking some connections and found that 5V MOLEX connector was somewhat broken, fixed that but still no go. I tried unplugging everything except the motherboard and it would still shutdown immediately. Checked all the connections and everything seemed to be in order.
System:
Q6600
EVGA 780i
EVGA 9600GT SSC x2
ThermalTake 850W Modular PSU
OCZ ReaperX HPC 2x2Gb PC2-8000
It was overclocked, but I loaded default BIOS settings - didn't help. It seems that it's either the PSU, CPU or MOBO, but i can't understand how can something break during the night. I don't really have access to any other suitable PSU, MOBO or CPU, so i can't replace and see if it works. All I have is a digital multimeter. Anyone got any suggestions? I'll try to find something myself in the meantime. Waiting for advice.

[squilliam]

Test it with a different PSU.
I'm willing to bet that will solve the issue.
It wouldn't be an overheating issue unless a heatsink was improperly installed.
It wouldn't power up if it were a CPU or Mobo issue.

[zeroja]

Heh, I just put the PC on its side wide open to see how long it'll hold. It has been running for 30 minutes now... I don't really have any other suitable PSU with a 8-pin ATX connector... and since I live quite far from anything that might have one it's a big big problem. It could not have overheated, it has been running PRIME small TFF test and topped at ~64 degrees celsius. The heatsink is re-re-re-installed from the first time. Although I do remember seeing some strange marks the last time I had the CPU taken out - it looked like two pins didn't touch contacts, tehy were a bit off... But in that case it should not have worked anyway, right? I'll keep the system running. It might be one of those times when the problem suddenly removes itself somehow.

[squilliam]

The 8-pin isn't necessary.
a 4-pin will work just fine.

[zeroja]

Oh, I guess I'll try that tomorrow. It's currently running, I'll see how long it'll last.

[Th3MadScientist]

if the cpu pins were bent or didnt make contact the computer would turn on but it would not get any video.