Well, after 3 months, I think I fixed the problem. I thought it was:
1. The memory
2. The GPU
3. The USB ports
4. SATA connection to the SSDs being dropped.
But when last week I was able to restart it by tapping on the Tempered Glass, then it had to be something loose.
SO, I checked:
1. The Front Panel Connector (maybe a shorted Power or Reset wire)
2. The SATA cables to the SSDs
then, i found the problem:
The 24pin power connector. It was loose, but it never clicks in. So I reseated it and it's seems fine.
Played Avengers, MS Flight Sim 2020 and Rocket League - no problem
Ran an FFMPEG (cmd line) conversion of a season of tv show - no problem (this always restarted the system)
Everything seems good now. It was probably one pin of the 24 loose and when the CPU kicked up, the cooling fan would ramp up and be enough to jostle the loose pin.
My taping the case would re-connect it.
Well.....thanks for the replies and
Wish me Luck