Things You'll Need
Instructions
Disconnect the controller from the controller port and blow air into the port. If there is a buildup of dust, the controller may not connect correctly.
Connect a second controller to the connection port. The current controller may just be internally damaged and not work at all, meaning the issue is with the controller and not the game system. There isn't anything you can do to fix the current controller.
Look over the cable running from the controller to the Super Nintendo. If the cable is damaged or cut, wrap electrical tape around the damaged area. This prevents the electrical current from exiting the cable before it reaches the gaming platform.
Dip a toothbrush in water and rub it over the buttons and control pad on the controller. This removes dirt and other debris that causes buttons to stick. Dry the buttons off with a soft towel once complete and wait a few hours for the controller to dry (water may have entered the controller through cracks around the buttons, and you want to make sure this water dries also).