This AM my 1/2 horse Craftsman openner openned but would not close - the unit sounds like it is going thorugh the motions but the chain is not moving.
Remove the casing from around the motor unit. You will probably find that the teeth of a neoprene (plastic) gear have worn away. If so,you can get replacement parts via the Sears website.
Slight change - it is a Steel-Craft openner (1994) model HBW077 and yes when I removed the casing the plastic teeth were worn away - -I am having difficulty finding a web site for parts - any ideas? Thanks