Adjust each sensor in small.
Garage door sensor not working.
Place one of the cardboard boxes in the garage doorway.
If the garage sensor is working properly the door will stop closing and go back to the open position.
My liftmaster garage door stopped closing the normal way.
If the sensors are working the garage door should immediately stop closing and return to the open position.
Sensor path make sure nothing is obstructing the sensor beam in general garage door sensors block the door from.
Press the remote control button to close the door.
Loosen the nuts just.
Cycle the garage door.
Cleaning and adjustment remove any debris dust or cobwebs from the electric eye lenses on each sensor with a clean rag.
Sensor power reconnect the sensor to its power supply a common cause of a malfunctioning garage door sensor is.
Sensor path make sure nothing is obstructing the sensor beam 1.
If you still haven t identified the problem or if you want to test the sensor wires themselves remove the sensors from the brackets.
Loosen the small nuts that hold each sensor to the l brackets with a small adjustable wrench.
Make sure the box is also placed in front of one of the photo eyes.
Strip both ends of wires from each sensor and twist like colored wires together.