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Garage Door Sensor Troubleshooting: Fix It Step by Step
If your garage door starts closing then immediately reverses - or won't close at all while the opener light blinks - the safety sensors are the prime suspect. These small photo-eye units near the floor are a required safety feature, and they're also the most common source of closing problems.
The good news: sensor issues are among the easiest garage door problems to fix yourself. Work through these steps before calling for help.
How the sensors work (and why they stop the door)
Each sensor sends an invisible infrared beam to its partner across the doorway. If anything breaks that beam while the door is closing - a person, a pet, a trash can, or even a misaligned sensor - the opener reverses the door as a safety response. The system is designed to fail safe: any doubt, and the door won't close.
Most openers signal a sensor problem with blinking lights: typically the opener's light blinks and the wall button may need to be held down to force the door closed. That's your cue to start here.
The five-minute fix sequence
Start by cleaning both sensor lenses with a soft cloth - dust, spiderwebs, and pollen (plentiful in Atlanta) are enough to break the beam. Next, check alignment: both sensors should face each other directly, with their indicator lights solid, not blinking. Gently loosen the bracket, aim the sensor until its light goes solid, and retighten.
Then check the wiring for damage - chewed, pinched, or corroded wires where they run along the wall. Finally, clear the doorway completely and test. If the lights are solid and the path is clear but the door still reverses, move to the next step.
- Clean both lenses with a soft, dry cloth
- Realign sensors until both indicator lights are solid
- Inspect wiring for damage or loose connections
- Remove all objects from the doorway
- Check for direct sunlight hitting a sensor lens
Sunlight interference: the sneaky culprit
In Atlanta, low-angle morning or evening sun shining directly into a sensor lens can overwhelm the infrared beam - the door works fine all day but refuses to close at sunset. If your problem follows a schedule, sunlight is likely the cause.
Fixes include swapping which side each sensor sits on, adding a small sun shield (a short piece of cardboard or PVC around the lens works), or repositioning the sensors slightly. A technician can solve this permanently in one visit.
When sensors aren't the problem
If both sensor lights are solid, the path is clear, and the door still won't close, the issue may be opener force or travel-limit settings, a broken spring making the door too heavy, or a failing logic board. These need professional diagnosis.
Call (678) 940-0457 and we'll connect you with a local Atlanta technician who can sort out sensors, settings, or deeper opener issues - with a free estimate first.
One more quick check before you call: look up your opener's diagnostic light codes in its manual. Many units blink a specific pattern for sensor faults versus logic-board or RPM-sensor issues, and reporting that exact code when you call helps the technician arrive with the right parts. It can easily turn a two-visit problem into a single visit.
Need a pro for this?
Reading helps — but most of these jobs are faster (and safer) in professional hands. Atlanta Garage Door Pros connects you with a local specialist: call (678) 940-0457 for a free estimate.