Sounds like a loose connection but this may help.

If when closing the door it reverses to the open position and the main light flashes 10 times it is a door sensor problem. Make sure the small light on each sensor is on and not flickering ever so slightly. (check closely) Tweak them a little even though they may seem to be okay. Check for 5vdc between terminals 2 and 3 on the rear of the motor unit. If there is no voltage or if it is greater than 6vdc the logic board is bad.