Computer shuts down instantly and then restarts itself at random times

[aykansozugecer]

Today, during gaming, my computer just shuts down like the power is out, and then it resarts itself after a second or so. Happens randomly and it happened 3 times today, all during gaming. Heat is not the problem, i checked the temps on both CPU and GPU during gaming and they were all fine. I don't know what's causing this, and would love your help!

 

[R_1]

My canned random reboot Rant
Random reboots are usually caused by the PSU, the RAM or software AND in that order of likely-hood.
PSU - If you can borrow/swap a PSU for testing. sibling/friend you can swap out the PSU and each system will be testing the other.
RAM - run the system with one stick of RAM see if stability returns if not Test all the RAM with memtest 86 for three passes or overnight. if you get no 0 errors after more than three passes the ram is good. with the random reboots I would suggest running this test after the PSU swap or after the PSU has been cleared.
Software - Drivers or other issues can cause reboots. Boot to a linux distro on a USB drive. mint linux will boot to memtest86. you can run the OS from the USB and await reboot.
end canned rant

I would look to the PSU. What model PSU do you have?