If you see that the sender sensor is not yellow and the receiver sensor is not green then this means that your sensors are probably off.
Garage door sensor will not light.
If they re turned on in both the sensors then there is no issue with the power supply.
If your garage door randomly doesn t close and the light blinks you may have a failing sensor.
Each sensor will usually have a light.
You ll need to first equip yourself with a wrench of some sort and a tape measure.
Look for small led lights on the sensors.
Check the mechanism s source and sensor leds.
One will have a green light used to show that the units are powered up and the other will have a red light to show that there s no obstruction between the sensors and that they re seeing each other.
A common cause of a malfunctioning garage door sensor is lack of power supply.
These sensors are little black boxes found on either side of the bottom of the garage door.
If you find the lights turned off in one or both the sensors it indicates that there is a problem in power supply.
If you own a garage door opener by lift master chamberlain or craftsman you ll notice that the sender sensor will usually shine a yellow light and the receiver sensor will usually shine a green light.
If both the red source and green sensor lights are on and not blinking then the door mechanism is working properly.
Light doesn t activate on garage door opener when you cross safety sensor beam chamberlain group products which include the liftmaster chamberlain sears craftsman line of garage door openers have a feature where the opener light will turn on if you cross the safety sensor beam shooting across the opening of your garage door.
The liftmaster garage door opener lights will flash for ten times.
For the door to close correctly without reversing the safety sensors need to be aligned perfectly and there should be nothing in the way of the light beam.
Raise the garage door using the control button on the garage wall or the remote control unit from a vehicle.
When the safety sensor is not properly aligned or something is obstructing the light beam the garage door will fail to close.
If one or both of the lights are off check the fuses breakers and plugs for problems.
The garage door sensor yellow light and the green light together create a solid illumination.