GPU shutting down while gaming, stress-tests working though

[philipp.cserny]

I was having random instant shutdowns with my setup for the last 5 months during normal desktop activities, gaming/full load was fine. I decided to start upgrading my system by swapping my PSU.

My old one is an "beQuiet Straight Power 600W 80plus Gold" and got the "Seasonic 650FX Focus Gold 650W" 2 days ago.

Desktop activities, like browsing, watching movies and so are working without any problems, no shutdowns. However, during gaming, my GPU shuts down mid gaming. The rest of the system still works, as I was able to still use discord. The game stopped too.

I did some stress tests in FurMark without any problems. The GPU was at 100% (Powerlimit was at 100% too) load and at 69°C (83°C VRM Temps).
Then I tried some Heaven Benchmark 4.0 and it crashed at Ultra Settings after some time. After the 3rd attempt and reinstalling NVIDIA drivers, it also passed the benchmark somehow and the games were running flawless again. Hours later, the same problems started again. Crashing ingame.

My specs are the following:

• 
  Intel Core i7-2600k @4.5GHz
  Asus P8P67 Deluxe rev3.0
  G.Skill Sniper 1333MHz 8GB DDR3
  Asus Strix GTX 970
  Samsung 840 Evo
  WD Black 1TB
  WD Blue 1TB
  Noctua NHD-14 CPU Cooler

help would be appriciated, thanks

 

[fredfinks]

Maybe intermittent GPU fan failure?
With the side panel off, get close to it when its running. Does it make any unusal noise or is noticibly louder?

Could it be a failing capacitor on mobo?

 

[philipp.cserny]

Maybe intermittent GPU fan failure?
With the side panel off, get close to it when its running. Does it make any unusal noise or is noticibly louder?

Could it be a failing capacitor on mobo?

Don't hear anything unusual "unfortunately". Switching back to my old PSU fixes the crashes while gaming, but the crashes during desktop work are back. I really think the mobo is the problem, but i don't know how to make sure.

 

[fredfinks]

These problems are a pain.
Think its mobo or video card.