Sorry that it's not an easy fix. Maybe go find a yellow donor for the board if that doesn't work?
So this weekend I had a 7-hour drive, and I didn't want to be away from the kids, so I took all three of them with me since this is the last weekend before school starts. Unfortunately, both Switches needed to be charged, and they had left both of my GBA SPs on, so they were both dead. I didn't want to go hunting for my DS or 3DS, as my office is a wreck, so I just grabbed my old Regular Gameboy. I grabbed a case for it and two games, Tetris and Super Mario Land 2. I tested both games before I left the house, but once we got on the road SML2 stopped working, and they didn't want to play Tetris. Also, the battery connector on the bottom left had some corrosion on it and the battery wouldn't always connect to it. Is there a fix for that or should I just order a replacement part?