The start capacitor can cause the problem you describe.

Thanks, don_1_2006.

After I replaced the start capacitor, the motor starts working. But I still cannot close the garage door. Everytime I pressed the remote button, it moves down several inches and then back to the open position. Any suggestion?

If the main light is flashing 10 times when the door reverses it is a door sensor problem. Make sure they are pointed at one another and the small light on each one is lit and not flickering.

If this isn't the case, increase the down force just a little and try. This adjustment is on the rear of the motor unit near where all those white wires go.

Thanks, Don.

After I increased the down force and it works fine now. You are a life saver.