Garage Door Won't Open or Close — Diagnosis Guide

A garage door that will not open or close is caused by one of four issues: a power outage or tripped breaker, a dead transmitter battery, a disconnected emergency release cord, or a broken spring or cable. This guide diagnoses each in order from safest and simplest to most dangerous.

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   Step 1: Check the power and opener unit

   Confirm the opener unit has power — the LED on the motor unit should be lit. Check if the outlet has power by plugging in a lamp. If the outlet is controlled by a wall switch (common in garages), check that the switch is on. If there is no power, check the circuit breaker for the garage.

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   Step 2: Replace the remote battery and re-pair if necessary

   Dead remote batteries are the most common garage door complaint. Replace with a fresh CR2032 or CR2016 battery (varies by remote). If the door still does not respond, re-pair the remote: press the Learn button on the motor unit (usually purple, yellow, or orange) until the indicator light comes on, then press the remote button until the motor unit light blinks twice. Test.

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   Step 3: Check the safety sensors

   All garage door openers installed after 1993 have safety reversal sensors — two infrared photoelectric eyes mounted at the bottom of the door tracks (about 4–6 inches from the floor). If their beam is blocked or the sensors are misaligned, the door will not close. Both sensors should have a steady LED light (usually green on one side, amber on the other). Misaligned sensors have a blinking light. Realign by loosening the wing nut, adjusting the sensor bracket until the LED is steady, and retightening.

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   Step 4: Check for a disconnected emergency cord

   The red emergency release cord disconnects the door from the opener for manual operation. If it was pulled (common during a power outage), the door is no longer connected to the motor. With the door closed, pull the cord toward the door (not toward the ceiling) to re-engage the trolley. You will feel or hear a click when it reconnects. Test the opener.

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   Step 5: Inspect the springs and cables — do not repair yourself

   Look at the torsion spring (horizontal bar above the door) and the lift cables (running along each side of the door from the bottom bracket to the drum). A broken spring leaves a visible gap in the coil. Frayed or snapped cables will be apparent. If either is broken, do not attempt to use the door — the door can drop suddenly and cause serious injury. Spring and cable replacement requires special winding tools and professional knowledge.