Topic: SNES Final Fantasy III cartridge problems.

I have a copy of Final Fantasy III on the Super Nintendo that's been giving me problems. I'm not the original owner of this cartridge so I do not know the history of it. This issue is two fold so I will try explain the best I can. Upon starting the game and going to the main save file screen I can't access all the saves. There are 3 files but I can only use the 1. I assumed possibly corupt files but I've never ran into that before so I'm not entirely sure. My cursor is very sporadic in the main menu and trying to select the different things in the menu (Item, Ability, Equip, Accessory, Status Configure, Save) is very frustrating. The cursor doesn't go where you press on the D-pad. If you push down multiple times it doesn't go down on the list it will go down once then back up then down 3 spaces etc. Also things in the inventory are skewed and letters don't line up correctly. When at a save point I couldn't save because the cursor wouldn't go to the save spot in the menu. I tried different controllers and different consoles and no change. I replaced the battery which obviously erased all the save files but it still has the issues of navigating the menu. Has anyone ever heard of this happening before? Any ideas would be appreciated. I thought possibly replacing a capacitor on the cartridge but not entirely sure what the capacitor does for the cartridge. I've replaced and re-soldered many components that have went bad on consoles but I'm an electrician by trade and circuit boards are a little beyond my expertise.