Door opener jammed
I have a Sears Craftsman 1/2 HP garage door opener (41A4315-6C) that has stoped half way up. I disconnected the door from the trolley, but can't get the trolley to move. when I push the button (from the wall or remote) the motor hums, reverses, then hums again.I checked the chain and trolley and nothing seems to be blocking it.Any suggestions? Thanks.