Well, somehow the display got damaged in the process. The T-CON board which is within the lid at the bottom of the LDC panel. A common thing I have seen in the last few years is the excessive cleaning has killed many! What happens is people use a spray cleaner directly on the screen to clean it without knowing it the cleaner drips down wetting the small T-CON logic board so it gets corrosion damage! Here’s a good writeup on how the T-Con works [https://www.electronica-pt.com/images/fbfiles/files/SONY_T_CON_training_manual.pdf|Sony T-CON Training Manual]
[image|2340411]
You’ll need to replace the display assembly to fix this [guide|27657].
The bad news is finding one! Lots of people are holding onto the older systems as either they meet their needs or they just don’t like the newer system’s (butterfly keyboard) & (lack of ports and no internal expansion). Keep an eye here or do your own search using the P/N [https://www.thebookyard.com/parts-retina-macbook-pro-15.php?cPath=39_368_371&sort=2a&filter_id=14|2013/14 - 15” MacBook Pro Display Assembly, Apple P/N 661-8310]