It likely has something to do with the optos on the opto board for the right flipper. Inspect the plastic part to make sure that it's not broken, and try taking a q-tip with some alcohol to clean the opto LEDs. If that doesn't help, an opto on the board may have failed, and in that case, the easiest thing to do would be to replace the board. If both flipper buttons are the original boards, I usually replace both since when one fails, the other is generally soon to follow due to age.
(Topic ID: 259081)
Cincinnati, OH
