PC Randomly Restarts After Playing Games

[p.gutierrez760]

I know there are a dozens of these cases floating around, but I don't know what to do anymore.

I have tested my power supply (just the ATX 24 pin) using a multimeter and all the voltages are within their tolerances. I ran FurMark for about an hour, Heavenly for about 45 minutes, and prime95 for about an hour without any problems such as overheating or restarting. I've updated my graphics drivers and even my bios and still continue to have the same problem. When I play Overwatch my PC restarts in the home screen (without even playing a single match) after about a minute of starting the game. When I play Witcher 3, my PC restarts after about 10 minutes of playing. I'm able to play "light" games such as gwent for several hours.

Any help is greatly appreciated. I'm lost at this point and don't know what else I can do.

cpu: Intel I7-4790k (not overclocked)
gpu: Gigabyte GTX-970 Windforce (in SLI)
psu: Corsair HW750
mobo: Gigabyte ga-z97x-ud3h-bk
ram: Corsair Vengance 16GB 1600MHz
cooler: Corsair H105
os: Windows 10

 

[Guest]

Test your RAM. Download memtest, boot into it, and let it run. Do you get any errors?

 

[p.gutierrez760]

Test your RAM. Download memtest, boot into it, and let it run. Do you get any errors?

I ran memtest and I received no errors.

 

[Vic 40]

psu: Corsair HW750

Which one exactly is this?

I do suspect the psu.The way you test is with parts apart from each other,gpu alone+cpu alone,the games will put load on both.
The same with voltages,they might show different values when under load.You could read voltages from an empty molex connector (black+yellow wire) and see if the voltages are still good. Other option is looking with software,

How to make a log,

download hwinfo32,
install and open it,
check "sensors-only",
click "run",
at the bottom of the window click "logging start",
choose a name and place for the log like "hwinfolog" at the "desktop",
this log can be viewed/opened with either excel from Microsoft or libre office calc (last is freeware).