Strange Compass Issues After Powertrain meltdown

Pixhawk 4 (I guess…(2,4,8)) - MN8

Weird stuff, Mission Planner sees both internal and external compasses on the calibration screen but Pre-Arm always fails with one or another compass issue - Sometimes Prearm announces Compass 1 not found, sometimes it says compass zero not found (Compass 0??, ok…) I don’t see a Compass referenced anywhere as zero.
Then, the not found mesages go away and either a compass not confg’d or compass unhealthy may pop in there.
In calibration it only moves one of the progress indicators, the other remains blank so MP doesn’t see enough of it to act on.
Now a bit of a hook here, this was fine until recently, all worked well. Doing a lock-down test run the radio suddenly lost control of the Pixhawk (Octocopter). Failsafes all failed, no throttle response, no emergency shut switch…nothing. 2 motors dieseled themselves and their ESC’s into oblivion…blackest smoke I ever saw… and I had to reach in there and pull the battery (4s) to shut it down. Thankfully it was in lock down, had it been it flight you’d probably read about me in the news.

So, I am thinking my Pixhawk blew a gasket and am soliciting comments, advice, critiques, etc.
What do YOU think?