Diagnosing garage door sensor problem from technical viewpoint.

In this video I use a wiring diagram to show how garage door beam sensors work and how to determine if your problem is a wiring, component, or aiming issue. A typical symptom is that the door opener will open the door, but not close it because a malfunctioning sensor circuit mimics an obstruction to the door path. As a stopgap measure, you can sometimes press and hold the wired controller to override the sensor and close the door.