I have a 2-3 yr old craftsman 139.53985D with a problem that is similar to many I see here, but with a different twist. Part-way up or down, it stops - no blinking lights anywhere. Usually, hitting the button again allows it to complete the cycle, but sometimes, the unit goes completely dead - no lights at all - as if the plug was pulled or the power goes off. But that's not the problem, b/c after 3-5 mins, it comes back on without touching it in any way. Is there a heat sensor that could be shutting it down - I'm not noticing any straining or the like, and it often happens on the first push. I also do not see any sudden jarring during the run. The complete shut down is a pain! Any thoughts?

jthepaintman - if when the door reopens the main light flashes 10 times it is a door sensor problem. Make sure the sensors are pointed at one another and the small light on each one is lit and not flickering. If the main light isn't flashing when the door reopens try adjusting the 'down force' which is on the rear of the motor unit near where all those white wires go. Increase it and try.