If the led s on both sensors are off the problem is in the logic board or the sensor wiring.
Garage door won t go down light blinks.
When the infra red sensors are malfunctioning usually one of the sensor lights will be blinking.
Garage door opener light blinks led light blinking indicates a problem note.
Place a step ladder under the liftmaster motor so you can comfortably access the learn programming button.
The problem is either due to a blocked path between the sensors dirty eyes loose wires at the sensors or at the motor head or just bad sensors.
Then open and close the door.
Count the number of times the led light beside the learn button flashes before it pauses and begins blinking.
If your garage door sending sensor is showing a yellow light and the other does not show a green light it is likely they are misaligned.
However the two most common reasons include a problem with the lock button and malfunctioning safety reversing sensors.
Troubleshooting a liftmaster with a flashing light step 1.
If you own a new garage door opener that comes with a locking feature it s possible someone may have accidentally locked your garage door by pressing the lock button.
If one of the leds is not on the door sensors need to be replaced.
If this is your situation the first thing you ll want to do is make sure these sensors are properly lined up.
The garage door will automatically reverse if it encounters too much resistance or if the sensor beam is interrupted.
The movement should be fluid with no tough spots.
You will need to use a ladder to access this area.
There are several reasons why your garage door opener is doing this.
If any of these sensors should happen to get bumped or misaligned the infra red beam would be thrown off and the garage door won t go down.
Ten flashes of the light tells you there is a problem with the door safety sensor circuit.
The led light that is referred to in this article is the small light that is located on the opener near the adjustment learn or program buttons.
If one or both leds is blinking the sensors are misaligned.
The blink rate on the garage door opener service light points to various error codes.
You may want to check the back of the motor unit.
The transmitters remotes will not work to close the garage door.
Look at the led s on both door sensors.
The back of the motor has a circuit board with a service light as well.