Computer shuts off while playing Left 4 Dead 2

[big.bAd.boi!]

My computer just turn's off while i'm playing Left 4 Dead 2 Multiplayer. Computer turns off only when i'm in game. I was able to play single player for 1 & half hour, but today it all went kamikaze. Could not play single player, multiplayer, pc would shut off right wen i logged onto desktop.

Config is 2gb 667 Mhz ram, M2N-VM-DVI Mobo, AMD Athlon 64 X2 Dual core 4000+ 2.10Ghz, NVidia XFX 8800GT 512 Mb Alfa Dog Edition DDR2 GPU.

Couple of minutes ago while i was trying to trace problem, pc shut down couple of seconds right after i logged on to desktop, i had to give it a rest, i touched PSU it was not hot at all, but the card was considerably hot.

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Thermal paste is totally dry & i got coolermaster 500w PSU

 

[stalker]

Your PC is overheating.

Try running with the cabinet open/tablefan blowing at it.

If the PC does not shutdown, means you'll need a cleanup/reapplication of thermal goop.

 

[Aman27deep]

Its either ur PC ran too hot, forcing it to shut down, or ur PSU just sucks, and u might be needing to replace it.

 

[jojothedragon]

^Yep. Bad psu causes the pc to shut down instantly if the voltage decreases randomly. Or your thermal paste is completely dry.

 

[mastersquall]

coolermaster 500w PSU

let me guess cooler master extreme series right ?

Thermal paste is totally dry

how old is your pc well time for put some thermal paste .

 

[ankurshah]

It may be due to overheating,Even my PC used to shutdown due to overheating, now waiting for the Fan from U.S.