Opener will not run; wall button and remotes do nothing; courtesy light may be on; diagnostic LED on logic board flashes once repeatedly.

Safety first: Disconnect power to the Stanley garage door opener at the breaker before touching wiring. Do not operate the door if the safety reversing system is not working correctly.

Steps to check and correct photo eyes:

• 1. Inspect sensor lenses: Locate the Stanley safety sensors (photo eyes) mounted near the bottom of the vertical tracks on both sides of the door. Wipe the lenses with a soft, dry cloth to remove dust, cobwebs, or moisture.
• 2. Remove obstructions: Make sure nothing (brooms, trash cans, bikes, boxes) is blocking the line of sight between the sending and receiving sensors.
• 3. Check alignment: Loosen the wing nuts on each sensor bracket slightly. Adjust the sensors so they face each other directly and are at the same height. Tighten the wing nuts while holding them in alignment. Many Stanley sensors have an indicator LED; adjust until the LED on the receiving sensor glows solid.
• 4. Inspect wiring: With power off, check the low-voltage wires from the sensors back to the opener head. Look for staples driven through the wire, cuts, or corrosion at the terminal strip on the logic board. Re-strip and re-terminate any damaged ends, matching polarity as marked on the opener (e.g., SEN+ and SEN−).
• 5. Restore power and test: Turn power back on. Press the wall button with the door fully open. The door should close normally. If it only closes when you hold the wall button continuously, the sensor circuit is still not satisfied and needs further alignment or wiring repair.
• 6. Replace sensors if needed: If one sensor LED will not light even with correct wiring and alignment, the sensor may be defective. Replace the complete Stanley-compatible safety sensor kit and wire it according to the included diagram.