It's as if there's something between the two eye beam fixtures at the bottom of the door. Opens fine. But try to close and it reverses direction immediately. The only way to close it is by holding the button until the door is all the way down. The unit is from May '94, is 1/2 hp, model#(?) is HBW0777 or 41A4315-7A.
Thanks if anyone can help,
Lou