I am just asking this, as many other users have this issue with random power offs. The computer just turns off and is ready to be turned on again, Windows just logs an unexpected shutdown.
There is some surge detection in the code, which cannot be turned off and most people blame to cause the issue.
Asus RoG X370 Hero VI
I know it could be Asus' fault, this is just to dig if other had the issue.
I was running 1701 from Dembiecer last year with AGESA code 188.8.131.52.
Last month I updated to 3502 with AGESA 1000a and ever since I get random power offs.
It could be once a week or twice in 15min (boot after random power off, open browser, power off again, boot, runs for a week).
Watching a video on Youtube, playing a demanding game, working in a text file, makes no difference.
Then I tried the latest Beta version from Asus "Optimize performance for AMD Ryzen™ Desktop Processor with Radeon™ Vega Graphics" and it kept turning off.
I cannot go back to 1701, because the flashtool says the 1701 BIOS file is not valid.
The oldest version allowed by the tool is Version 3008 with "AGESA 1071 for new upcoming processors"
I'll see how this goes...
//edit: same with 3008 (AGESA 1071), I USB-Flashed it back to 1701 now.