I suppose there could be a situation where only certain screens would be corrupted if they drew pixels in certain areas that triggered a larger fault in the driver chip, or if the fault triggered only when the overall number of lit pixels crossed a certain threshold. Or maybe the display module responds to some kind of serial data protocol, and it's only failing on certain kinds of functions (like only text functions, or only line drawing functions). I don't know how the hardware of that thing works, I'm just saying software isn't the only possible reason for that behavior.