GDO Craftsman buzzing sound door won't open or close
I have Craftsman 1/2HP 139.18850 (1995).
The door or remotes won't open the door and I found another post that seems the same problem. "When pressing the wall button or outside keypad the motor (41A4315-7C) hums twice and does nothing. The green light up on the motor blinks 5 times, stops, blinks 5 times and so on"
Seems to indicate...The LED is blinking the code for "RPM sensor or motor overload".
I bought the 41C4398A RPM sensor assembly part and replaced it and the same problem happens so it's not the sensor itself.
My gears (worm, drive) look fine to me, a little chewed but still look 100% fine to me.
What else could cause the RPM sensor to stop the motor from turning? Is there some way to force turn the mechanism to see if it's jammed on a gear or tooth.
Not sure what to try next.