My computer shuts off on certain games

My computer completely shuts off when I start playing Max Payne 3 and the S.T.A.L.K.E.R games. By shut's off I mean everything literally stops as if somebody pulled out the power cord to the power supply. I looked at Event Viewer and it comes up with one critical error, the ID is (Event ID 41 - Kernel-Power) 

I went and did Star swarm stress test and when I choose Mantle it runs fine but when I choose D3D literally 1 second later my rig shuts off. Is this relevant to the PSU or is this a graphic card issue?  

 

If my hunch is correct my Power supply is faulty. I have no tools to check my Power supply so i'm out of luck if that's the reason why my computer is randomly shutting off when I play those games :/   

Do any of you have any idea's of what I should do/what the issue could be?

 

Now before you ask, here are my computers specs:

 

Operating System

Windows 7 Ultimate 64-bit SP1
 
CPU
AMD FX-8350 19 °C
Vishera 32nm Technology
 
CPU Cooling
cooler master hyper Evo 212
  
RAM
8.00GB Dual-Channel DDR3 @ 577MHz (11-11-11-28)
 
Motherboard
ASUSTeK COMPUTER INC. M5A99X EVO R2.0 (Socket 942) 30 °C
 
Graphics
VE247 (1920x1080@60Hz)
FPD2185W (1680x1050@60Hz)
3072MB ATI AMD Radeon R9 200 Series (Gigabyte) 41 °C
 
Storage
2794GB TOSHIBA DT01ACA300 SATA Disk Device (SATA) 33 °C
 
Power supply
EVGA SuperNOVE NEX 750 B 80 PLUS BRONZE Certified 750W Active PFC ATX12V v2.31/EPS 12V v2.91 
 
Optical Drives
DTSOFT Virtual CdRom Device
 
Audio
Corsair Vengeance 1500 Headset

sounds like a power-supply issue, from what I can tell it has 4 12v 20 amp rails, One of these rails could be bad or you may be going over the 20 amp over current protection.

 

The power-supply may be faulty, however you may find success in splitting and moving the gpu power load to different rails.