Garage Door Opener Remote Problem
I moved to a different house about four months ago, and it has a garage with a Craftsman garage door opener, model 139.53879, and no manual. The button on the wall operates the door fine. However, The remote unit has stopped working. I tried new batteries, but that didn't solve the problem. The remote has three buttons (large, medium, and small.) The large button opens and closes the door, and I have no idea what the functions are of the other two buttons. They are not marked. Can someone please help me? Thank you very much.