Garage door won't close? Start with the sensors

Look for something in the beam

A bin, a bike wheel, a coiled hose, a leaf pile. The beam is only a few inches off the floor and almost invisible, so anything low near the opening will stop it. Move everything clear of both sides and try again.

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Check the two sensor lights

Each sensor has a small LED. Most brands use one steady green and one steady amber. If either is off, flickering, or the colours differ from usual, the pair are not seeing each other.

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Wipe the lenses

Dust and cobwebs are enough to break the beam, and in Arizona that happens fast. A dry cloth on both lenses fixes a surprising number of these.

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Nudge one sensor gently

A knock from a car door or a bike is enough to knock one out of alignment. Move one very slightly until both lights go steady. If they will not hold steady, the bracket is loose or the sensor has failed.

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Look at the track for an obstruction

If the sensors are fine, something may be physically stopping the door — a bent track, a broken roller, or debris in the channel. Do not force the door past it.

Check the close-force setting

Openers have a force adjustment that drifts over time, and a door that has become stiff will trip it. This one is worth leaving alone — set too high, the safety reverse stops protecting anyone standing underneath.