The symptom of this is a garage door that is in constant motion opening fully then immediately descending only to start the same cycle again.
Liftmaster garage door closes then opens again.
As these wires short against the housing the electrical impulse causes the door opener to activate.
These steps should fix most doors.
This problem bugged me for several months.
Now press the remote control.
If your garage door is closing fully and then reversing to open again then it may be due to a problem with the close limit switch.
Close the garage door with the opener and watch it closely as it closes.
There may also be loose wire connections inside the button housing itself.
Don t just assume that if the path is clear that the sensors are ok.
Your garage door s logic board is the brain of your garage door opener.
To reconnect the garage door to your liftmaster garage door opener manually close the garage door pull the emergency release handle down.
Hopefully after you read this you won t have the same problem in the future.
Get logic board replacement.
If your garage door opens ok but won t close then it s possible the safety reversing sensors are not correctly aligned.
This brain can wear out in time so you could need a replacement.
This will cause the trolley to move into position and reconnect to the garage door.
If the garage door does not close completely or begins to close and then opens back up again the down limit switch needs.