If you find the lights turned off in one or both the sensors it indicates that there is a problem in power supply.
Linear garage door opener sensor problems.
This video is for a linear garage door opener.
Finally it s possible the garage door opener s motor has burned out and isn t operating at all.
Look for small led lights on the sensors.
Two things can cause this as well first there is an obstruction in the doorway and secondly safety sensors are misaligned.
The first is an obstruction in the path of the door and therefore in the path of the sensor.
A common cause of a malfunctioning garage door sensor is lack of power supply.
The most common problem with garage door openers is safety sensor misalignment.
When the led or the light bulb on your linear garage door opener flashes three times it means the problem is from the safety sensor.
Two types of accidental obstructions can cause the safety sensor to prevent a garage door from closing.
If they re turned on in both the sensors then there is no issue with the power supply.
This is a problem that will require you or a service person to replace it.
When this happens the door will reverse when closing.
If the circuit breaker or gfci is tripping repeatedly it s a sign that there is a short circuit somewhere in the system possibly even the garage door opener itself.