Computer shuts down in 3-4 seconds

[Legendaryhero7]

Hello everyone, so as the title says I have been having some troubles with my desktop.

It started when I was playing MafiaII, when all of a sudden a blue screen came up and said that it was saving memory or something of the sort. This has happened before a couple of times randomly in the past, but all I had to do was restart the system and everything would be peachy keen.
So after this happened I went through the normal restarting process, everything was going normally, and then as the windows 7 logo was doing it's crazy startup thing, it froze. This has never happened before, so I tried to restart it again, this time it only runs for about 3 seconds and then shuts down.

So now I am stuck in this hole trying to find something to give me a clue as of what the problem is.

Here are my specs:
EVGA GeForce 7050 nForce 610iQ socket 775,
intel core 2 quad Q6700 2.66GHZ, 3GB DDR2-667 memory,
ZEROtherm/ CF900 / socket 775 / copper base / heatpipes / CPU cooler.

Here is what I tried so far...
Bought a new PSU and replace the old one. That didn't do anything, so I brought it back.
Took the CPU fan off and replaced the thermal grease. During that process I cleaned out the fan, took out the mobo, and cleaned everything. I also made sure the wiring was correct and that nothing was loose.
I've been trying all this with the bare minimals, so I'm not sure what it could be. I checked the RAM aswell so I think that's out as well.

So now I come to you guys, I've been searching all day for some solutions but every one seems to have a different solution. Any help is greatly appreciated!

I disconnected the 4 pin 12v input to the CPU and it atleast stayed on, nothing happened but the computer didn't turn itself off.. Not to sure what this means.

 

[EXCellR8]

which graphics card are you using and can you boot into Safe Mode? if so, uninstall your graphics drivers and then reinstall them. it's sounding like the graphics card or the drivers are to blame, which is a fairly common problem. Windows may not be booting because there is a problem with the driver and therefore needs to be reverted or updated. the card could also be overheating in which case you may need to let it cool off before trying to boot windows again.

 

[kristin48616]

If I were you, I will install the cpu and then test, then add memory and test, then add the video card. If there are any problems, I know exactly which component is the culprit. More specifically, start with cpu and its heat sink and fan (hsf) and psu only. Turn on your system and wait the error beeps. You might want to try this. You'll want to note your beep patterns (this assumes you have a speaker on your mobo or you have the case speaker plugged into the mobo), as they may differ depending on your make of bios. But you should get distinctly different beep codes as you add components.

 

[Legendaryhero7]

@ excellr8: I can't really get that far, it shuts off within 3 seconds of being on.
@kristin48616: I did all of that with only the CPU heatsink and psu. it doesn't give me any error beeps, I do know for a fact that the mobo has on board speakers, It would usually beep at the beginning of being turned on. But not any more

 

[nismo91]

I disconnected the 4 pin 12v input to the CPU and it atleast stayed on, nothing happened but the computer didn't turn itself off.. Not to sure what this means.

I'm pretty sure you'll need a motherboard replacement. It happened to me before, well, cheap mATX board to rescue.

 

[mailpup]

By the way, it isn't a good practice to disconnect power connections with the PC still on if I read correctly.

 

[Ritwik7]

+1 nismo91. That is a symptom for a fried mobo.

 

[Legendaryhero7]

Okay thanks a bunch, I'll order a new board. I'll let you know what happens, thanks everyone.
Oh and Mailpup, yeh I made it sound like I did it while it was on, but I disconnected it when it was off, sorry for the misunderstanding

 

[mailpup]

Thanks for clearing that up and do let us know how the new motherboard works out.