This YouTube video by How to Home shows you what might be stopping your garage door from closing and how to fix it.
Garage doors that don’t close are caused by a bent track rail, an obstruction along the path, or a malfunctioning sensor. Even the slightest bend or curve may interfere with the door closing. If nothing is found, sensors should be inspected.
Sensors may be rectangle or square in shape, have a lense pointing to the opposite side of the garage, and both a red and green light near the lens.
Sensors are required for safety purposes.
If there is no green light showing, the back of the sensor should be inspected for possible loose wiring that may have come out of the wire plugs. Sensors should be checked to ensure they are level with the lenses pointing straight at each other. Blocking one or both of the sensors should cause the red light to come on. If it doesn’t, make sure the lenses are clean. If the red light still doesn’t come on, then one or both sensors may need replacing.
Individuals who cannot perform these steps or who need additional assistance should consult a professional who specializes in garage door repair services.