OS: Windows 10 Home (up-to-date)
CPU: Processor Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz, 3301 Mhz, 6 Core(s), 12 Logical Processor(s)
GPU: Radeon RX Vega 64 (up-to-date, driver ver 19.6.3)
RAM: 16 GB
PSU: 750W CoolerMaster
The Issue: Regular/minimal PC usage such as browsing the web, watching things, and running minor apps is fine. When I run a game, the video output suddenly stops. The PC is still going, the fans are still turning and power is on, but the screen goes black and says "DVI No Output". Also the game's sound will continue for a moment before looping. The only way to recover from this is if I then crash the PC manually.
The conditions for this change, infuriatingly. Sometimes it doesn't crash my games at all for days on end, and then suddenly one day it just flares up all over again.
At first this was thought to be a heat issue, but lately it has been crashing when the PC has barely gone beyond it's regular 30-40C range.
I suspected that the cause of this was when there are high-processing demands from a game (such as a big battle with many NPCs in Middle Earth Shadow of War, large amounts of objects loading and processing in a Sims 4 session, big events in Sea of Thieves, etc) but as of today my theory of this has been confounded by the fact that the GPU crashes within seconds of loading Assassin's Creed Unity's starting cutscene.
This is not the fault of my PC's other hardware. Every part has been stress-tested continuously by repair stores for 24 hours and passed without a hitch.
I'm really reaching my wit's end with this. I've done every test and search and fix and update that I can think of for months now. Cables have been replaced and every speck of dust obliterated. Professionals have no idea what's going on or how to help me. Scan (the warranty holders) refuse to replace the card for me because they cannot replicate the issue when they run tests on this card in their own set-ups.
I've always had minor issues with this card since I got it, (e.g. texture buffering and tearing in ESO, lag in Witcher 3 that "lesser" cards never had, the inability to load Fallout 4 2K graphics mods without intense lag - something the 980 before it had never struggled with) but I always ignored them since they were minor. Then this crashing started a couple months ago, becoming more frequent each time it happened.
I sure never had any issues like this when I ran an Nvidia card in the same system for years.
Can anyone help?