Here are some pictures I took while I was working on it. Next time I open it I'll try to take more. The front of the board looks immaculate and shows no corrosion, but unfortunately I haven't gotten a picture of it yet:
https://imgur.com/gallery/qODtz

Hey guys,
The other day the controls on one of my gameboy pockets started acting up. A and B were acting as left and right, and down was acting like start and sometimes visa-versa. I'm guessing there's a short circuit somewhere but the problem is that I can't find it.
I opened it up to clean it and the first thing I noticed was a heavy amount of corrosion around the negative terminal. I cleaned it up as best as I could but the issue is still there. I went over it with some alcohol and cotton swabs about 3 times over and while the issue is less frequent, it's still there.
Has anyone encountered this issue? I'm thinking about removing the battery contacts and replacing them since there is still a little corrosion that I couldn't get out.
I'll post some pictures as soon as I get a chance.
Any advice you guys have would be great, thanks!
P.S. Also, where can I get battery contacts for the pocket? All I can find are ones for the DMG. If you know any sellers that have them please post them. Thanks!