I've seen something similar happen when the 1 10uf cap pads get ruined but not exactly the same. Also, are you by chance using a generic ac adapter? Does the same thing happen on batteries? I wonder if this is the sign of an actual bad screen.
The burn in on the screen is completely normal.
I will recheck the 10uf again. No I first tried this unit reassembled on batteries and noticed the problem, since then I have been trouble shooting it partially disassembled with power from a 1st party NEC TE AC adapter. That would kinda suck if the screen has a legit problem, Though it might be nice to upgrade to a newer LCD.