PW2 still dead. display still shows last PW3 screen saver image. The only thing that works on the PW2 is the LED blinking when no battery installed.
And these boards have a ton of numbered test points on the back (no useful labels though). The probably sat on a pin bed fixture for testing...
PW3 boots up fine with its original screen. YKNR just meant it was unsatisfied with not finding enough pixels to satisfy its GUI layout...
And SHAZAM! Swapping screens made the Home menu appear! It pushed the "Cloud | On Device ..." menu down to make room for the home menu. It is much "more better" now -- EXCEPT the touchscreen is not working... That was a worthwhile experiment, with unexpectedly positive results, but now I have to get the touchscreen working again...
EDIT: Touch not working at all, even after several hard reboots. Even after reseating the touch cable several times (with battery removed). It worked fairly well, then intermittently, then not at all, then after swapping boards still not at all. But I got my menus back -- though I cannot touch and use them now... Not sure if that is progress or not...