Start with the beam path
Safety sensors are normally mounted near the floor on opposite sides of the opening. An object, dirt, moisture, or a visibly shifted sensor can interrupt the beam and prevent normal closing.
Safe checks
- Remove objects, leaves, webs, and other debris from the doorway and sensor path.
- Gently wipe each lens with a clean, soft cloth.
- From a safe position, check whether the sensors visibly face each other and whether their brackets are damaged.
- Look for loose, pinched, cut, or chewed low-voltage wiring without opening the opener or altering connections.
- Check the exact opener manual for the meaning of its indicator pattern.
What the result means
- The light becomes steady after clearing or cleaning: The beam was likely obstructed or the lens was obscured.
- One sensor is dark: That sensor may not have power, or its wiring or hardware may be damaged.
- Blinking continues with a clear path: Visible alignment, wiring, sensor, or opener issues may remain.
- The door will not close or reverses: Continue with Garage Door Won’t Close or Garage Door Closes, Then Opens Again, matching the actual movement.
Indicator colors and blink counts are manufacturer- and model-specific. A generic blink-code table would be unreliable.
When to stop DIY
Do not bypass, cover, disconnect, or defeat the safety sensors. Stop operating the door if it also binds, becomes crooked, leaves its track, or has a loose cable.
When to call a professional
Call for service when a sensor, bracket, or wire is visibly damaged, an indicator remains abnormal after safe cleaning and obstruction checks, or the door has a separate mechanical problem.