My pc is restarting only playing games

Hey guys , my pc just restarts when im playing games , if i do stress tests or something else is ok , if i run something to check the temperatures he wont restart but if i dont he will. The temperatures are all normal and the drivers are all updated, and i already formated the pc and changed windows and still does the same thing , i got it in video but i cant put it here

specs
Motherboard-Msi z97 gaming
Gpu-Strix 980
cpu-intel core i7 4790
psu-xfx xtr 650w
16gb ram 1866hz

Memories-sdd 240gb
-hybrid 2 terabytes