Solved! The Mystery of the AMD "monitor off hang" - sort of.

VirtualLarry

No Lifer
Aug 25, 2001
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Well, I don't have the "root cause" of AMD cards never monitor-waking on HDMI in Windows 10 while under heavy GPU load (DC / mining), I do know why pressing the ATX soft-off "Power Button" doesn't initiate a shutdown.

In fact, I have a rig here, with an Intel iGPU (Haswell), running Win10 Pro 1809 64-bit, that wasn't the currently-selected display, and I tried repeatedly to press the Power button to get it to do a controlled shutdown, but it was doing nada.

So, I selected that input on my TV/monitor, and voila!

YOU CANNOT PRESS THE POWER BUTTON TO SHUT DOWN WINDOWS 10, WHILE AT THE LOCK SCREEN. (Regardless if you have a password or not.)

I had to hit ENTER a few times, to actually "enter Windows 10 desktop", and THEN the ATX soft-off Power button shut down (controlled shutdown).