If your garage door starts down, stops and goes back up, and the opener light blinks, a blocked or misaligned safety sensor is one possible cause. Wiring faults, binding hardware and travel settings can also cause reversal. We align, repair and replace the photo-eye sensors on LiftMaster, Chamberlain, Genie, Craftsman and Linear openers across Sacramento, usually the same day. Call (916) 838-8182.

What the sensors do

The two small eyes mounted a few inches off the floor on each side of the opening send an invisible beam across the doorway. If anything breaks that beam while the door is closing, the opener reverses. Photo eyes are part of the opener's entrapment protection. They work alongside its contact-reversal system and must be installed and tested according to the model's instructions.

Checks you can safely make first

Keep the door stationary and stay outside its travel path. Do not reach beneath a stuck, crooked or damaged door to clean a sensor; keep clear and call.

Look for something in the beam: a trash can, a bike wheel, a broom, a cardboard box.
Wipe both lenses with a soft dry cloth. Remove visible dust and cobwebs.
Check the indicator lights. Use your model's indicator guide: light colors and blink patterns vary. A dark or blinking light can indicate an obstruction, alignment problem, lost power or wiring fault.
Look at the brackets. If one has been bumped, the sensor may be pointing slightly off.
Late afternoon sun shining directly into a sensor can also trip it. Note whether the problem only happens at certain times.

If those do not fix it, stop there and book a visit.

Never bypass the sensors

Do not move sensors out of the doorway, alter their wiring to defeat them, or force a door closed after a safety fault. Keep people and pets clear of the opening. If the sensors keep faulting, the fix is repair or replacement.

When it needs a technician

Wires chewed by rodents, cut by a mower, or pinched behind a bracket.
Sensors that will not hold alignment because the bracket or the track is bent.
Water, insect or sun damage inside the sensor housing.
The opener logic board failing to read the sensors at all.
An older opener with unavailable sensors. We check for an approved replacement pair; without a compatible repair, the opener needs replacement.

What we do on the visit

Test the existing sensors and the wiring run back to the opener.
Replace or realign what has failed, and mount the brackets so they stay put.
Test photo-eye protection and contact reversal separately as the opener manual specifies, then check door balance and the travel and force setup.
Show you the indicator guide and how to recognize a sensor fault; the lights alone may not identify its cause.

What it costs

Repair and service visits carry a $45 diagnostic trip fee. Once we know whether it is alignment, wiring, a sensor pair or the opener, you get a written price before any work starts.

Sensor questions we get

Why does my door reverse right before it touches the floor?

Travel settings or a binding door may be involved, even with steady sensor lights. We inspect the door and test the opener. Do not increase closing force to overcome resistance.

Can I install sensors myself?

The sensors must be compatible with the opener and mounted, wired and tested as its manual specifies. If you cannot verify each of those requirements, book an installation. Never reuse incompatible sensors or bypass a fault.

Do all garage doors need sensors?

A powered residential door needs the entrapment protection specified for its opener. Photo eyes are the common system on current models. Have older equipment without them assessed for replacement; a working motor alone does not establish safety. Opener repair and replacement.