A common issue with the original Game Boy Color is batteries being left in the compartment and leaking acid over time. Often this is a simple fix of replacing the eroded battery contacts.

Unscrew your console using a tri-wing screwdriver (we sell them), and use a small pin or toothpick to lift the metal tab keeping the original springs in place from the inside of the back case.

Pull out the old springs, and place these new springs into position.

These springs lack a locking tab so we find it best to slightly bend them in the middle so they press-fit into the shell and don't come out. Alternatively you can glue or double-sided tape them in, or simply leave them in as they are and once the batteries are installed they won't move.