PC starting and powering down randomly

[LuthorHarkon7]

My PC powers down and starts randomly. Sometimes it can load BIOS and Windows for hours without a problem, sometimes it shuts down before the beep. After switching the CMOS battery the problem was gone for a few days before it reappeared. I ruled out a heat problem. It seems the PC can idle in BIOS, but because the times when it shutsdown are random it's hard to verify. My Specs are :
EVGA GTX 960
GA-78LMT-S2P GIGABYTE Motherboard
AMD FX-4100 CPU
Pure Power L8 630W CM PSU

 

[NeonDragon]

How old is your PSU? it seems its a good psu for the most part but can be a little finicky, also did you recently get a new GPU?

 

[LuthorHarkon7]

How old is your PSU? it seems its a good psu for the most part but can be a little finicky, also did you recently get a new GPU?

I changed my cpu and gpu late sommer 2015. I reseated my gpu when i changed my cmos battery, but the problem persisted before this.

 

[AliMickey]

try a different cmos battery(probs wont fix anything) maybe cooling is not sufficient?

 

[LuthorHarkon7]

try a different cmos battery(probs wont fix anything) maybe cooling is not sufficient?

I don't think the cooling is a problem.Whenever i checked the cpu an gpu temperatures, they were fine. Also the PC shuts down regardless of the temperature

 

[AliMickey]

try a different cmos battery(probs wont fix anything) maybe cooling is not sufficient?

I don't think the cooling is a problem.Whenever i checked the cpu an gpu temperatures, they were fine. Also the PC shuts down regardless of the temperature

ok. do you have a different cpu you can try?

 

[LuthorHarkon7]

ok. do you have a different cpu you can try?[/quotemsg]

No, I don't have one.

 

[AliMickey]

ok. do you have a different cpu you can try?

No, I don't have one.[/quotemsg]

fully reset bios to factory settings, run virus check and malwarebytes. CCleaner as well.

 

[AliMickey]

How did you fix it?