[SOLVED] Ryzen 2700x System suddenly locking up - need help pinpointing cause

[andreascocq]

My setup:
ASUS Pro 370x MB
Ryzen 2700x
32 GB RAM (2666)
Sharkoon 720w Powersupply
GTX 1070Ti (8 GB)

I just changed the CPU cooler from a Noctua tower to a AOI 240 watercooling (DeepCooling Captain 240).
Did a Prime95 run for about an hour and it showed temperatures max 65 degrees, about 12 degrees cooler than before.
Also played games for a few hours ... no problem there.
Then all of a sudden I heard a „click“ and the monitor went blank („no signal“). The whole LED lighting stuff stayed „normal“, but the PC did not respond to the power off or the reset buttons.
Had to hit the power switch on the power supply to be able to reboot.
The windows event viewer showed nothing unusual (other than that the PC was turned off without proper shutdown).
Now when I run the PC (even without load), after 20 - 30 minutes, it will show the same behavior (locking up).
I have rebooted and called up the BIOS setup and just let it run there overnight, without any problem.

During normal use, I monitor CPU (and GPU) temperatures and they always appear OK (CPU around 50, GPU around 70).

At this point, I am not sure what the next logical things to research would be, because the error conditions are unclear to me.

Any help / idea would be appreciated.

 

[andreascocq]

OK ... I got the problem solved ...

Turns out that the Windows powermanagement had been (re-)set to send the PC into hibernation after a timeperiod. I changed that setting back to the way I had it before (NO timeout etc.) and since then, the system is functioning again as expected.
Still find it weird though that the attempt to go into power safe mode caused it to hang itself so thoroughly