Grasp the mounting bracket with the claw of a hammer, if the sensor bracket is bent. Straighten the bracket to allow the sensor to face the opposite sensor.
Find the LED light on each of the safety sensors, and look for the one whose LED light is flickering or will not illuminate. Place a ball in between the path of the safety sensors. Look for the sensor whose LED light stops illuminating. This is the receiving sensor, and the one that requires adjusting. Move the ball out of the way.
Loosen, but do not remove, the securing nut on the back of the sensor with a 7/16-inch wrench.
Maneuver the sensor up and down until the LED illuminates without flickering. Hold the sensor steady and tighten the securing nut. Continue adjusting as necessary until the LED light remains lit when the sensor is secure.