Hello Bob,

I have a garage door model # 41A5021-3C that starts giving trouble since the last past weeks.The problem is the garage door opener can not be opened entirely.Every time, I try to open it by pressing the wall switch; it's lifting like 6 to 12 inches and then stops until I push the switch again to close it.

Please tell me what might be wrong with it. I am looking forward to hearing from you.

Onald

GDO have a force overload limit that will stop them. That is the most likely problem, but depending on the specific model it might be a possiblity of a failure in the upper limit stop.

First disconnect the GDO from the door and operate the door manually. Does it operate smoothly and balanced. If it does not then it needs to be fixed.

Then run the opener without the door connected. If it travels the full distance and you don't see any jerking them reconnect the door and adjust the opening force limit.