***I can tell you that I have a BE QUIET! Straight Power 11 as well.*** Mine is a Platinum 850w which is only about ***2 years old*** and always kept clean. I am currently trying to diagnose the same basic issue of ***spontaneous PC shutdowns while gaming.*** It usually happens within the first 2-3 minutes of launching the game. But not every game. Less graphically intense games either last a lot longer or don't crash my PC at all. It has been getting progressively worse over the past couple days. I've tried just about every troubleshoot imaginable from software, driver and BIOS updates and roll backs to Mem-tests, different cables, Stress tests, temp and voltage monitoring etc, etc.. Both my CPU and GPU run cool and have normal voltage and temps in all of my stress tests. I've run simultaneous stress tests maxing both out and they function normally which is very strange considering a game that hammers them less shuts the whole system down. After all my testing, I kept coming back to a GPU driver issue but no matter which driver I use in the last year of driver releases, it doesn't seem to make any difference. I always did fresh GPU driver installs after a DDU safe mode uninstall and reinstall. I'm basically down to it's either something faulty on the motherboard or it's the PSU which are both very hard to diagnose. My RX 6950XT GPU is just past warranty so I may open it up and check paste and thermal pads to rule that out if the new PSU I ordered doesn't fix it. I had a Seasonic 850w before the Be Quiet one I have now. The Seasonic lasted me almost 8 years before the 5v rail died. If it turns out to be my current Be Quiet Straight Power 11 that is at fault, I will never be buying from them again. Very expensive for it to go out within 2 years. We shall see.. I'll update this when the new PSU shows up in a couple days.