Plan it

The safety sensors are blocked or out of line. Try this before you call

The opener is refusing to close because a safety system is not satisfied. That system exists because children died under doors, so fix the sensor rather than bypassing it.

What is probably happening

The two photo eyes at the bottom of the tracks are misaligned, dirty, or something is between them. Chamberlain: if the opener light flashes 10 times, it is a safety sensor problem.
A sensor wire has been pulled loose or cut, often by a rake, a bin, or a mouse.
The sensors are fine and the LOCK is on: Chamberlain says two flashes means the lock feature on the wall control is on. That stops remotes, not closing, so it is the less likely match.
Photo eyes have been federally required on residential openers since 1993. The CPSC rule followed 54 deaths of children aged 2 to 14 entrapped under automatic doors.

Do this in the next five minutes

Clear everything from the door path and wipe both sensor lenses with a soft cloth.
Look at the small lights on each sensor. Chamberlain: both should glow steadily, green on the receiving eye and amber on the sending eye. A blinking or dark light means misalignment or a wiring fault.
Loosen the wing nut, point the lenses at each other until the light glows steady, and tighten. They should sit no higher than 6 inches off the floor.
Check the thin wires from each sensor back to the opener for a break or a loose terminal.
If you must close the door now on an older opener: press and hold the wall button until the door reaches the floor. Chamberlain says this override was removed from openers made after February 3, 2022.

Do not

Do not tape the sensors together facing each other to bypass them. The door will then close on anything in its path, including a child.
Do not disconnect the sensors at the opener. Same reason.
Do not pay a service call before trying alignment. Angi puts sensor repair at $150 to $250, and the fix is usually the wing nut.

Who to call

A garage door technician, if alignment does not fix it

A door company replaces sensors and wiring in one short visit. No electrician is needed, the sensors run on low voltage from the opener.

Get a free shortlist The seven questions for this trade

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What it should cost

$150 to $250

Sensor repair by a professional. A sensor pair as a part is $25 to $50

Source: Angi, garage door repair cost and opener installation cost, updated August 2026. View source

National published range, not a quote for your job. The full cost table for this trade is on the garage doors page.

Ask this contractor, on the phone, before anyone comes out

Tap each one as you ask it.

Is it the sensors, the wiring, or the opener's board, and what does each cost separately?
Will you test the safety reversal with a 1.5 inch board before you leave?
What is the total including the call fee?

End the call if

A new opener sold for a sensor fault. Sensors are a $25 to $50 part.
Any technician who offers to bypass or remove the sensors so the door 'just works'.

Where this comes from

Not my problem, tap through instead Every garage doors answer