Black screen when playing games - PSU?

[casdes]

I am having a problem when I try to play a game on my computer. I start up the game and anytime within instant-2hours, my pc will go to a black screen as if it has shut down but the fans are still spinning.

Specs:
- Phenom II X6 1100t - stock running at 3.3 (3.7 turbo)
- Corsair Vengeance 1600Mhz 8GB - running at 1333
- Corsair GS800w
- Asus Crosshair IV Formula
- MSi R9 390 - stock

- Windows 8.1 / 10 64bit (does it on both)

Games affected that I have noticed so far:
- WoW
- GTA 5
- H1Z1
- ESO

 

Information:
MSInfo - http://pastebin.com/1kF02F9H
dxdiag - http://pastebin.com/qD394Vnu
hwmonitor log - http://pastebin.com/rC5NRkbS
hwmonitor image - https://i.imgur.com/Wl7PaRq.png

Things that I have done to try to disagnose/fix the problem:

- Monitored temps with HWMonitor - doesn't seem to be an issue (see above screenshot)

- Replaced the thermal paste on my CPU
- Windows memory diagnostic test to check ram - no issues

- Prime95 (blend for 10hrs) - no issues

- FurMark - black screen as soon as i start the stress test

- Removed and refitted RAM, and moved them into different slots

- Refitted the CPU cooler
- Downgraded back to windows 8.1

- Uninstalled Raptr as I was told that may be causing some conflicts

- Moved graphics card from x16 slot into the x8 slot.

 

Will add more when I can think of what else I have tried.

Can anyone help at all? Have a feeling it might be my PSU but I'm not 100% sure

[Rarity]

get another psu and test first ..your problems when running gta 5 (other games in your list i dont play though)sound kinda similar to mine when playing gta 5 ..initally thought it was the drivers , but turned out to be the psu .. 

[casdes]

get another psu and test first ..your problems when running gta 5 (other games in your list i dont play though)sound kinda similar to mine when playing gta 5 ..initally thought it was the drivers , but turned out to be the psu .. 

Not sure if I can get my hands on another PSU but will try to do so. I initially thought it was the drivers too when I played GTA5 as I heard there was a problem with them, as well as with the witcher 3 and a couple other games but it didn't solve the problem. Will have to try to find another PSU then

[GoldSrc]

When the screen goes black, is the sound still there?

[casdes]

When the screen goes black, is the sound still there?

Nope

[GoldSrc]

Nope

Try to downclock your CPU, it could be your PSU but I'm not sure.