Computer reboots without warning

[thug407]

Specs

Windows 8 pro
Nvidia GTX 560ti GPU
Phenom 2 1100T x6 CPU
Asus Crosshair V formula MB
700W Xion Power supply
8G ram

When im playing games my computer reboots by it self without BSOD. Its not a heating issue because my CPU is liquid cooled runs at 30-35C and GPU the most i seen is 60C when playing BF3...i have all drivers updated and scanned for registry errors viruses....everything is clean...

My power supply Xion 700W is pretty old and everything else is (newer) .....im thinking its power supply going bad because sometimes rarely computer lock ups also in games and the only thing i can do is restart...

any help suggestions would be nice..

also computer is clean no dust or anything like that...

 

[rezervesizeja]

Reinstalling gpu drivers could help.

 

[strongvpn]

Reinstalling gpu drivers could help.

i think so，try it

 

[thug407]

Reinstalling gpu drivers could help.

I tried that didn't work....also swapped gpus...same problem

 

[thug407]

Reinstalling gpu drivers could help.

I tried that didnt work....also tried swapping gpus.....put old one in gtx 275 same problem