Edit for solution. Ended up being the cpu. Bought a 5600x that worked flawlessly, and my 5900x was still under warranty. Just got the replacement back from amd and it's also working good.
Longshot here, but maybe someone can help.
PC either hard locks or blue screens.
Ryzen 5900x
32 gigs ram
2080Super
EVGA 750w power supply
Did all the driver suggestion online. SFC memtest etc. Stripped down to single stick of ram, tried both individually in different slots, GPU and ssd. GPU and ssd have been used in another pc without issue. Windows 10, 11 fresh installs. Tried pop os locked up during install twice. Just replaced my motherboard and the boot ssd and it was working for a few days, and is now doing the same lock up or dpc_watchdog. At this point, the only hardware that hasn't been swapped out to test is the power supply, cpu and case. And I've disconnected everything from the case save the power button.
I've been building my own pc's for over 20 years and have never encountered such a difficult to diagnose problem. Could it be the power supply? CPU? This is 90% brand new now and still giving me the same issue.