Problem with PC, Prime95 temps

Doge Verm

Reputable
Jan 22, 2015
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Hey guys, I have a problem with my PC for a few weeks now and Im really worried that I broke something.
My PC shutdowns for no reason when gaming or the sound loops and the screen goes to a random colour, This happens on OLD games such as Medieval 2 Total War and even Lord of the Rings Online.
When that happens, CPU and GPU are between 40-50 degrees, I was also told my PSU might have a problem supplying enough power for components (Strike-X 800W)
I ran Prime95 for a minute because I was afraid I might break my CPU because it reached 75 degrees.
Should I run Prime95 for 5mins or couple of hours to see if the PC shutdowns or loops?
Specs:

GPU - GTX 770
CPU - Intel Core i7-4770k
MOBO - G1 Sniper 5
RAM - 16GB Overclockers UK
PSU - Strike-X 800W
I have a heatsink mounted onto the CPU with two corsair fans and 2 additional fans in the case (1 front and 1 back)
 

Doge Verm

Reputable
Jan 22, 2015
94
0
4,630