The door will not close and the light is blinking. Start at the two little eyes near the floor.
Every opener since 1993 has a pair of photo-eyes six inches off the floor. One sends an infrared beam, the other catches it, and if anything breaks the beam while the door is closing, the door goes back up. In the West Valley the beam gets broken by dust, sun and lizards more than by anything else.
When the door will not close from the remote or the wall button, climbs back up after starting down, and the opener light blinks, the opener is reporting that it cannot see the beam. That is the system working, not failing. On most units you can close the door by holding the wall button down, which overrides the sensors and confirms the diagnosis. The causes in Surprise, in order of how often they turn up: a bracket bumped by a trash can or a bike so the eyes no longer line up; a film of dust on the lens after a haboob; afternoon sun flooding the receiving eye on a west-facing garage; a low-voltage wire cut by a string trimmer, pinched by a shelf, or chewed by a packrat or a gecko; and a sensor that died in a surge.
The fix is usually quick. The technician reads both indicator lights, which should hold steady when the eyes are aligned, loosens the wing nuts, re-aims, tightens, and cleans both lenses. For sun blinding, the sender and receiver are swapped so the receiver faces away from the west, or a hood is fitted. Damaged wire is traced, spliced or re-run and stapled clear of the track and the floor. A dead sensor is replaced as a pair, matched to the opener's brand. Then the close force is checked and the reverse test is run on a block, because aligned eyes are only half of the safety system.
If the door still reverses with both lights steady, the fault is in the door rather than the sensors: a binding roller, a dry hinge, springs that have lost tension so the opener is fighting the door's weight, or a close force set so light the door reverses on the weather seal. That gets looked at next, rather than selling a second pair of sensors.
How the job is handled
Lights read first
Both indicator lights checked; a flickering or dark receiver tells the story before a screwdriver comes out.
Realigned and cleaned
Brackets re-aimed and tightened, lenses wiped, the beam confirmed end to end.
Sun fixes
Sender and receiver swapped or a hood fitted for west-facing doors that fail every afternoon.
Wire traced and repaired
Cuts, pinches and chew damage found, spliced or re-run, stapled clear of the track.
Pairs matched to the opener
Brand-matched and universal sensors for LiftMaster, Chamberlain, Genie and the rest.
Reverse test included
Close force checked and the block test run, because a working beam is not the whole safety system.
Sensor repair: West Valley prices for 2026
| Work | Range | What changes it |
|---|---|---|
| Alignment and cleaning | $69 – $119 | The trip fee; often the whole fix |
| Sensor pair replaced | $95 – $190 | Aligned and tested |
| Wire repair or re-run | $80 – $170 | Length and route |
| Sun hoods or re-aim | $35 – $85 | West-facing garages |
| Force and limit adjustment | Included | With any sensor visit |
| Logic board, if the sensor circuit failed | $170 – $340 | After a surge |
Planning ranges for Surprise and the surrounding West Valley cities in 2026. The figure you pay is the one written down on site before the work starts; quotes on replacement doors and new openers are free and hold for 30 days.
From the field
Asked about sensor repair
The door closes only when I hold the wall button. Why?
The opener cannot see the beam, so it refuses to close from a remote; holding the wall button overrides the sensors. Look at the two eyes near the floor. A dark or flickering light means misaligned, blocked or wired wrong.
Can I align them myself?
Often. Loosen the wing nut, aim the eye at its partner until both lights hold steady, tighten, test. If the light will not stay on, or the wire looks damaged, call.
Why does it only fail late in the afternoon?
Sun. The low western sun floods the receiving eye and the opener reads a blocked beam. Swapping sender and receiver or adding a hood ends it.
Can I just disconnect the sensors?
No. Most openers will not run without them, and bypassing them removes the reversing protection the standard requires. It is written for children and pets.
Something chewed through the wire. Is that normal?
In the West Valley, yes. Packrats and geckos find the low-voltage wire regularly. It gets re-run and stapled clear of the floor.
The eyes are aligned and the door still reverses.
Then the door is binding or the close force is too light. The technician checks rollers, hinges and spring balance before touching another sensor.