“ it has this weird issue where the top of the screen becomes blue (sometimes it's a sliver at top sometimes it's almost the whole screen) and the division between blue and normal is so clean it almost looks like an OSD despite the set predating that.”
The partial blue screen is a fine tuning indicator, which turns on when you touch the tuning knob. I think that you minimize the height for best tuning, but I could be backwards.
jr