Ahoy Holy-SNES,

I would start by cleaning the board thoroughly and carefully. Then verify every trace on that board with a dmm.
Hard to tell by the picture but it looks like some traces are damaged.

Also looks like their soldering iron was a little too hot and yet there appears to be cold solder joints/lifted/missing bridged? pads.
To repair that board correctly will take a lot of time. It should have been sent out to a pro. There are so many small traces pads on that board
that even a good rework tech will have a challenge to make it work let alone look good.
Take your time and be in a good frame of mind when reworking it. Good luck.

Milton