This seems to be a popular topic, but I have not found an identical problem to mine in any forums - maybe you can help
My newly build computer shuts down randomly after a period of time, often around an hour, sometimes earlier. When shutting down the fans keep running, everything else is off, and neither (soft) power and reset button work, only a hard reset with the off-switch.
Here are the components:
Gigabyte 990FX-UD3 (Rev 4.0), BIOS F2 (latest)
AMD FX8350 (8 cores, black edition, but not overclocked)
8 GB RAM Crucial DDR3 (2 banks) 2200MHz, all memory settings at AUTO and verified as correct, PC3-12800
Gigabyte HD 7870 2GB RAM GPU
BeQuiet 850W Dark Power Pro PSU
Samsung 850EVO SSD Drive, SATA 3.0
3 other (standard spinning drives)
2 DVD writers (SATA)
OS: Windows 10, latest Catalyst 15.3 Beta Graphics Driver
during World of Tanks games, especially when starting up a battle
after quitting Shadow of Mordor games (but never during), especially after long games
randomly while browsing or using files during internet explorer
when I leave the machine running by itself in idle
an hour or so after I put the machine into sleep mode (it wakes up, the fans are running, but nothing works, requires a switch-off)
I have tried:
replacing the motherboard with an identical version (thank you Amazon)
removing all hard drives but the boot drive (that seemed to make it crash more often)
updating all drivers
running CPU and GPU tests for hours - without crash (for example Valley Benchmark)
All burn-in tests do not cause the Core temperature to rise of CPU or GPU out of their respective safe parameters.
I know the immediate response will be "Windows 10", but why would that cause the machine to wake itself up from sleep mode and die?
The last suspect is the Power supply. This power supply came from my old machine and is 6 years old, but has up to now never shown a problem in a set-up only slightly slower (4 cores, older Gigabyte motherboard).
I am at wits end and have ordered a new PSU to try out if this solves the problem, but if anyone has seen a similar problem or can give me any pointers on what to try - why does the machine crash on idle? Why the complete shut down without the ability to reset?
Thanks for your help