Monitors shut down randomly

[Legendary555555]

About a couple weeks ago I was playing cod when suddenly my monitors just turned off completely but I could still hear my music going through so I tried turning on the monitor myself but there was no signal going through to which I restarted the computer and everything went back to normal. Yesterday I was playing the Witcher  and it happened again only this time I decided to check and see if my computer was making any sounds and it was. One of the fans was spinning really fast but I couldn’t tell which one it was, whether the cpu fan or the gpu fans or the fan in the back end that blows out the hot air. Atm I’m running an extended diagnostic test to see if I find any problems. Any help is much appreciated. 
 

Specs are:

2070 super FE

i9-9900k

2x16 Corsair ram

Corsair RM 750

 

Edit: After better inspection I believe the fan that is spinning very fast is the exhaust fan. I ran a stress test on my gpu to see if my monitor would shut down again sure enough it did however I've look up the issue and it seems to be either the psu or the gpu.