Question B360-HD3 won't power down after Win10 update

[Fiiji]

Hi,

I bought a new system about a year ago and haven't had any problems until Windows pretty much forced me to update to 1903 a couple of days ago. Since the update I've noticed a couple of issues which may or may not be related:

1) System now won't power down. It appears to shut down, but then a second or so later, later all the fans start spinning at high speeds and the CD drive can still be ejected. No video output though and front power lights on case are off. If I power off at the wall and then back on again, fans start spinning immediately, but no boot until I press the power on button.

2) If I power off at the wall and then back on again, the BIOS resets. Battery seems fine and system time is preserved, just the settings are lost/reset to defaults. This may have been going on a while, but I haven't noticed anything so I assume it started the same time as issue (1), i.e. after Window updated.

Surely Windows updates can't have broken the BIOS, but the timing is too coincidental to ignore. I've tried disabling all the power settings in Windows (hibernate, fast startup, e.t.c.) and have updated all drivers I can find, but no difference. A search suggest that the main BIOS may be corrupt and the lost settings are due to the backup kicking in? The settings are preserved as long as I don't cut power at the wall.

Any ideas?

B360-HD3
i5 8400
GeForce GTX 1060
Win10

Cheers.

 

[Fiiji]

Some more info:

I've tried rolling back all the drivers I can, as well as uninstalling Intel Management Agent but that didn't help. I installed Intel Rapid Storage which made one if my hard drives disappear, but did nothing for the power issue, so I uninstalled which allowed Windows to detect the hard drive again. I also tried leaving the PSU unplugged for a while and noticed that when I plugged it back in that the fans still started spinning straight away, but far slower than if I just unplugged for a short period. I'm left a bit puzzled.