My Genie Pro Max Chain drive stopped working. With door attached to trolly/carriage, when I hit the button, there is an initial click, and then just a buzz/hum..door does not move. If I dis-enage door from carriage and hit button, chain moves just fine. I have done the balance door tests etc..I have had three different so-called "in the know" folks tell me three different things. 1) Capacitoris bad 2) gear(s) are bad and 3 ) Carriage/ Trolley is bad. Any help here would be awesome... THANKS

Z