My Craftsman 139.53515SR – I/2HP garage door opener has worked fine for many years. For no reason that I can see, it stopped opening or closing the door yesterday. When I push the button to raise or lower it I hear some noise, like it's trying to work, then in a few seconds it stops and there has been no motion of the door or chain that raises and lowers it.
Disengaging the door from the chain allows me to raise and lower the door without problem.
It failed for 24 hours then started working.
Here is a video of it not working:(
What do you think is wrong?
Best Answer
It sounds to me like the motor is not starting. If you can manually lift the door, then I'd start by checking the motor capacitor. If it's on the way out, that could explain the intermittent failure.
You may notice physical damage to the capacitor (leaking, buldging, etc.). More likely you'll have to measure the capacitance, to make sure it's within a good operating range.
While the unit is open, inspect all the gears and sprockets. Look for worn teeth, or gears that don't mesh properly. Also inspect the sprocket on top of the unit (you'll have to remove the guard), to make sure it's meshing with the lift chain/belt.