Opener will not run, wall button and remotes do nothing, single flash or code “1” on Guardian logic board LED.

Safety first: Disconnect power to the opener before touching wiring. Do not bypass safety sensors for regular use; they prevent the door from closing on people or objects.

• Check for obstructions: Make sure nothing is blocking the infrared beam between the two Guardian safety sensors mounted near the bottom of the tracks.
• Verify sensor LEDs: On most Guardian sensors, one LED is solid (power) and the other should be solid when aligned. If one or both are off or flickering, alignment or wiring is suspect.
• Realign sensors: Loosen the wing nuts on the sensor brackets, gently rotate each sensor until both LEDs are solid. Tighten the nuts while keeping alignment.
• Inspect wiring: Follow the low-voltage wires from the sensors back to the Guardian control board. Look for staples through the wire, cuts, or corrosion. Ensure the white and white/black (or white/striped) wires are landed on the correct sensor terminals on the logic board.
• Test operation: Restore power and try closing the door using the wall button. If the door now closes and the LED code clears, the issue was alignment or wiring.
• Replace sensors if needed: If one sensor LED never lights even with correct wiring and power, replace the pair of Guardian-compatible safety sensors as a set.