Display ghosting and horizontal lines when fully open

My friend's Macbook recently went kaput due to a logic board issue. Completely dead for no apparent reason. Apple wanted $500+ for diagnostics. The usual.

I got a new logic board and swapped it in, and sure enough, it boots once more, but I'm now getting an issue with the display slowly ghosting and developing lines in it until it freezes entirely. However, this only occurs when the display is fully opened; if I lower it halfway, it goes right back to normal. I've seen this issue before, with the culprit likely being the cables from the display itself, but I didn't have to touch those cables to replace the logic board. Could it be an issue with the replacement logic board, or one of the ends of the display cable connecting the display daughter board and logic board? It doesn't seem likely since it it seems something is failing only when the lid is fully opened. But it's odd that it's happening after the board replacement when the cables that bend with the hinge were untouched and this wasn't an issue before (to my knowledge), unless it sustained this damage from her initial Apple store visit.

Any input is appreciated before I get a whole new display.