You have to take off the back, remove the battery, then take a small screwdriver and remove the 4 screws on the sides. Then you'll see all the wires and circuits inside. With a pencil, carefully rub using the led part of the pencil, the 2 circles on one of the circuit boards about 10 times. Be careful not to mess any of the wires up. Put back the 4 screws, put the battery back in, and put the cover back on.
WARNING: DEBUGGING IS RISKY! MAKE SURE YOU KNOW WHAT YOU'RE DOING!!!!