Things You'll Need
Instructions
Spray glass cleaner onto any stickers on your SNES cartridge and allow it to soak into the stickers. Use a razor blade to scrape the stickers off by starting from the edge of the sticker and scraping the sticker off the cartridge.
Wet a magic eraser and scrub any marks or writing off your SNES cartridge.
Wet a cotton swab with isopropyl alcohol and rub the cotton swab on both sides of the contacts in the SNES cartridge.
Take the SNES controller apart by using a Phillips head screwdriver to loosen the screws on the back of the controller. Wet a cotton swab slightly so there is no excess alcohol that can drop into the open controller or circuitry board and ruin the SNES controller. Wipe around the inside edges of the controller and take the circuit board out of the controller. Clean around the buttons and the spaces they fit. Use a toothpick to get tough grime out of the edges in the controller. Be careful not to drip alcohol into the controller and do not touch the circuit board with the alcohol. Allow the controller to dry and reassemble.