How do I reset my garage door sensor?

To reset your garage door sensor that is part of safety system preventing door from closing when obstructed, you need to clean, realign, and power cycle to restore solid LED indicators. Safety sensors are small boxes near bottom of door tracks, one sending infrared beam and one receiving, with LEDs showing status. If door won't close and sensor LEDs blink or are off, sensors need reset. First, inspect sensors for dirt, cobwebs, leaves, or debris blocking lens and clean with soft cloth. Ensure sensors are aligned facing each other with clear line of sight and no obstruction, as even slight misalignment causes failure. Loosen wing nut or bracket screw holding sensor and tilt sensor slightly until both LEDs are solid, not blinking, with sending sensor usually solid yellow or orange and receiving solid green; when aligned, receiving LED stays solid green. Check wiring for loose or damaged wires at sensors and at opener unit, tightening terminal screws. To reset electronics, unplug garage door opener from power outlet for 30 seconds to a minute, then plug back in, which resets logic board and sensors. After reset, test by closing door and waving broom through beam to ensure door reverses when beam broken. If sensors still fail after cleaning, aligning, and power reset, they may be damaged and need replacement costing 20 to 50 dollars, which can be installed DIY with same wiring.