How to determine if FCC connector is causing no screen issue

Hello! I bought a Pokewalker off ebay for parts and made it a personal project to repair it. It came fully functional aside from the screen not displaying. I have attempted to replace the screen but have found that the screen itself is not the issue. This was confirmed when I put the screen from the broken Pokewalker into a working Wii U Fit meter and it worked. My next problem is figuring out what is really causing the screen issue. My main theory is that somehow the FCC connector on the board that the screen uses itself has stopped working but I'm not sure how I can check this before buying a replacement in some way. Any advice or is this just something I need to replace to see if it fixes anything?

EDIT: I have attached photos. I put the board underneath an old child toy microscope and after some fiddling I was able to see the pins. The pins do look fine however I'm not really able to get a picture of them with the microscope. I did manage to get a more zoomed photo with a magnifying glass however. While using the microscope the only thing of note I found was a component that part of the screens FCC connector fed right into. I was able to get a picture of it and circled in red the part on the motherboard.

There looks to be some corrosion on the part and was wondering if anyone else could confirm as this could make the fix either much easier or much harder