Mid 2014 MacBook Pro A1398 Randomly Shuts Down

This machine has done this for so long I've been trying things here and there. Here are some things I have tried

- Most recently I had the board service by a reputable tech and the problem persists (re-beaded / replaced a couple chips that were common problems).

- Reset SMC/PRAM

- Tried a new SSD module

- Tried new memory

- Reinstalled multiple times

- Installed and booted / ran from external drive

- Top of the line thermal paste

The computer checks out with ASD and other system diagnostics. Runs cool. Clean as a whistle. Everything says this should be a great laptop.

However - it randomly (sometimes it has "fits" and sometimes it stays on for an hour or two) shuts down. Screen goes black (backlight still on) and it proceeds to shutdown. When I turn it back on it does NOT give me the shutdown due to a problem UNLESS I hold the power button after the screen goes dark and force it down. Seems as though it shuts down normally.

Also when opening back up - it seems to have "forgotten" the last 30 seconds or so of what I was doing.

I have inspected logs to pieces it seems they just stop - and I see the bootlog entry. Nothing that stands out at me. Before I started writing this I did unplug my power adapter and it happened right then.. likely coincidental cause it is not repeatable.

I am currently in safe mode and it seems to be working fine. I was hoping this could rule out my Iris chip but since it's the ONLY graphics chip in here I suppose it doesn't. Totally lost! Any help would be much appreciated.

I deleted my system log and booted to safe mode hoping it would act up but I will have to post this - go back to regular mode - let it misbehave and then post the log then.