Randomly shutting down when running a game?

[supermudfish]

My computer has recently been shutting down and restarting without warning when playing any kind of video game. For clarification i have a pretty good rig but even small games like half life or csgo have been turning it off.

My first thought was my cpu overheating however gpu, cpu and psu temperatures are fine. My cpu averages out at around 60 during games while the gpu runs at around seventy.

I decided to try a benchmark test to try and check when the temperature crashes and within seconds of beginning it crashes. The last temperature the program reads is usually around 71.

Im at a loss really of what to do. Its only when playing video games does this happen but more graphic intensive games tend to cause it to happen much more quickly.

Specs are down below and thanks for reading !!

GPU: Nvidia gtx 980 ti
CPU: Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz, 4001 Mhz, 4 Core(s), 8 Logical Processor(s)
Motherboard: Gigabyte Z97-HD3
PSU: 700 Watt

EDIT: I did a few stress tests on my psu because it hadnt occurred to me that it might actually be failing due to degradation and found that the 12V dips below 11.4 just before it turns off. I think this is the issue then

 

[popatim]

Which PSU is that ?
Since it's shutting down instead of crashing, it is on my suspect list.

 

[supermudfish]

It’s a 700w cool master so I don’t think it’s a lack of power

 

[norcalsc]

psu is starting to fail I suspect