Two things can cause this as well first there is an obstruction in the doorway and secondly safety sensors are misaligned.
Linear garage door opener sensor problems.
Two types of accidental obstructions can cause the safety sensor to prevent a garage door from closing.
The first is an obstruction in the path of the door and therefore in the path of the sensor.
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.
If you are having problems closing the garage door please che.
This video is for a linear garage door opener.
Linear garage door opener not closing.
A common cause of a malfunctioning garage door sensor is lack of power supply.
If they re turned on in both the sensors then there is no issue with the power supply.
The most common problem with garage door openers is safety sensor misalignment.
This is a problem that will require you or a service person to replace it.
Finally it s possible the garage door opener s motor has burned out and isn t operating at all.
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.
Look for small led lights on the sensors.