HDD WD CAVIAR BLUE WD10EZEX 1TB SATA/600 64MB cache
GPU GIGABYTE VGA ATI Radeon HD7850 2GB DDR5
PSU Forton 500W HEXA 500, PFC, PCI-E, >80%
Win 7 Home Premium SP1 64bit
After about 2 years it started to crash - just a sudden black screen, sound going on for 2 seconds then becoming a loud buzz or a short loop - after I played 30 to 90 minutes some of my games, mostly FPS like CSGO, PUBG, other like Dota2 or World of Tanks. Never crashed with Heartstone, Company of Heroes and other low spec games. Games like WoT was enough to set to very low graphics or set gpu's fan from the default 40% to 60 or 70 to stop the problem, some games crashed even then and even at around gpu 40°C. After a crash in competitive csgo I restarted immediately to get back asap, which sometimes resulted in another crash few mins after.
I tried to troubleshoot but didn't find anything. Even tried stress tests but it never crashed on them. After 3 years and many crashes my motherboard died and I got a new one.
The first crash after getting a new mb and reinstalling windows happened in Seven: The Days Long Gone (specs) on low graphics setting. After that I installed OpenHardwareMonitor and tested the game with fan at 100% and logged it. And put graphics to High and gpu load was 70-80% and 40-45°C and even reduced the fan speed to 75%. Seemed stable and didn't crash for the whole 40 minutes. Then I turned the fan to auto default 40% and it crashed after a while (CRASH 1 in log).
Then I ran PUBG with gpu 80% fan and 58°C which crashed after 20 mins. (CRASH 2)
And then CSGO with gpu at 70% fan and 52°C which crashed after 1.5 hours. (CRASH 3) And I was in competitive so I restarted asap and joined asap and even without the OpenHardwareMonitor. It crashed after 10 minutes.
Here is a link to the logs I combined of those 3 crashes. The first one made me think temperature meter was involved, cause it jumped to 74°C. But the next ones didn't even get to 60°C.