About 50% of the time, if I put the Win10 computer to sleep (either manually or via regular time of inactivity), it sleeps and wakes normally.

However, starting 2 months ago, I randomly get a failed sleep.

* Screen sleeps, mouse and keyboard sleep
* Computer fans do not turn off and system light does not blink (which it normally does when sleep works)
* When I wake it, the mouse wakes, but the screen is still off and system appears hung
* Have to reboot via computer reset switch to restore

I think the issue is that it won't go into sleep properly. I have not been able to correlate what conditions trigger a good or bad sleep.

Ideas on how to troubleshoot?