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

Unscrew your console using a Tri-wing and Philips screwdrivers (we sell them), then unscrew and remove the motherboard from the case.

Desolder the old springs off the board using a soldering iron, clean up the solder using a desolder pump, and re-solder the new springs into place.