It's the motor, had a similar problem on the way down and sometimes it wouldn't even go down until I took it apart to lube it and then it failed again, no motion.
Took the motor out and took it apart and cleaned up the rotor and other dirty parts in it.
Works okay now but someday will need replacing.
Got the holes drilled for the bolts so it won't be hard to do.
If you are planning on riviting, instead of drilling to get at the mounting bolts, get a replacement motor. :smile: