Mac Mini Late 2014 running most recent Sierra w...

Sleep won’t Wake Mac Mini Late 2014 OS Sierra 10.12.6

Press gently, once on the power button.

Did that. . As well as long press on power button. I have gone as far as a complete wipe and restore of OS and i’ve Had a new logic board installed. No luck. Also.. for what it’s worth, if asleep it will eventually shut off. Once again, to boot up... unplug, wait and plug back in..