I also had a similar problem with my Sears Craftsman garage door opener. While Sears said the part may be covered by warranty, it would cost $65 for them to get it done. I am considering filing a class action lawsuit against Sears. If you would like more information on joining the class, please email a summary of your experience with Sears and/or the garage door opener, along with your contact information: name, tele. no., e-mail address. Thanks, Mitchell Rait. mrait@comcast.net

If tapping on the unit restores function the first thing I would look for is a loose connection. BTW, Chamberlain makes most, if not all, of Craftsman openers.

First thing I would do is open it up and make sure the battery is still okay. On the rear of the motor unit near where all those white wires go you will find the smart/learn button. Press and immediately release this and then walk over to your keypad and key in any 4 digit code you like and press enter.

Make sure the black cap is on the back of the motor shaft and pressed all the way on. Make sure the 4 pin circuit board next to that black cap is plugged in. If neither one of those two are the issue and you replaced the worm gear as well, what you will need to do is loosen the coupler up on the back of the motor shaft. On the front of the motor (door side) where that shaft pokes through, push it back as far as it will go and hold it there while you tighten the coupler back up. One of these three problems is always the issue for people who have done this repair themselves.