Computer Turns Off Without Warning Instantly

[ZoroTheGreat]

The problem I've been experiencing is said in the tittle: My PC turns off without warning instantly. It's not a Windows shutdown, my computer fans stop running, my leds turn off, and my computer won't turn on. It will turn on by pressing the power button after the random shutdown but sometimes I have to turn my power supply on and off for the computer to turn back on. It will only randomly shutoff when I am playing GTA 5 or CS:GO. I can understand it having a problem with GTA 5 but CS:GO isn't a very labor intensive game so I'm not sure what's happening. Also something to note is my PSU fan that's supposed to turn on at 40% load but when playing GTA 5 the fan won't start spinning even though the PSU is hot to the touch and my GPU is running at 75-80C and my CPU is running at 70C.

Here are my PC Specs:
CPU = Fx 9370 @ 4.4GHz
CPU Cooler = TPC 812
Motherboard = ASUS SABERTOOTH 990FX R2.0
GPU = MSI R9 280X 3G
PSU = Corsair RM850 850w
OS = Windows 8.1

Any help would be greatly appreciated.
Thanks!

 

[Dark Lord of Tech]

Cooler is nowhere near good enough for a 9370.

Your choices for the 9000 series:

Asrock 970 Performance
ASRock 990FX Extreme9
ASRock 990FX Extreme6
Asus Crosshair V Formula-Z
Asus M5A99FX PRO R2.0
Asus Sabertooth 990FX R2.0
Gigabyte GA-990FXA-UD3 R4.0\5.0
Gigabyte GA-990FXA-UD5
Gigabyte GA-990FXA-UD7
MSI 990FXA-GD80V2

AMD.COM

Warning: This power draw of this CPU is almost twice that of the average CPU. Due to this, AMD recommends using at minimum a 1000W power supply. For cooling, AMD recommends using either either closed loop liquid cooling or full system liquid cooling.

 

[fkr]

those temps ae way to high on the CPU. you should not go over 60C from what i know. I would get a nice all in one water cooler

 

[Ok Go]

seems like a heat related problem triggering the kill switch on the mobo.
try opening your case and do a strest test on individual parts i.e. occt for cpu and furmark strest test for gpu while monitoring the temps.
revert to default clock if you overclock any of your hardware. it might be just dust or faulty thermal compound, or a faulty bios in worst case scenario.

 

[Dark Lord of Tech]

His cooler isn't NEARLY good enough to cool a 9000 series chip.

Needs a H100i at minimum , custom loops are the best for a 9000 series CPU.