The short version: when a garage door refuses to open, the cause is almost always one of six things. Blocked or misaligned safety sensors, the manual release rope pulled, a dead remote battery, a tripped breaker, a broken torsion spring, or a snapped cable. The first four you can fix yourself in under a minute. The last two need a tech, and you should not try to force the door open if you suspect either one. Here is how to tell them apart.
1. Check the Safety Sensors First
Every residential garage door opener built since 1993 has two photoeye sensors near the floor, one on each side of the door, about six inches up. They shoot an invisible infrared beam across the opening. If anything breaks that beam, the opener refuses to close the door, and on some models it refuses to open too. Look at both sensors. One should glow green, one should glow amber or red. If either light is off or blinking, you have a problem.
Step one: clean the lenses with a dry cloth. Spider webs, salt mist on coastal homes, and dust will block the beam. Step two: look for obstructions. A pool noodle, a rake, a bag of mulch. Step three: re-aim. Gently bend the mounting bracket until both LEDs glow solid. If the LEDs come back on and the door works, you are done.
2. Is the Manual Release Pulled?
The red rope hanging from the opener trolley disconnects the door from the motor. Once pulled, the opener motor will run all day and the door will not move because nothing is attached to it. This happens when kids pull the rope, when the door is bumped during opener service, or when the rope catches on a tall vehicle. Pull the rope toward the door (not down) to re-engage the trolley, then hit the wall button. You should hear a click as the trolley re-couples to the chain or belt.
3. Dead Remote or Wall Button
If the wall button works but the remotes do not, swap the CR2032 or 9-volt battery in the remote. LiftMaster, Genie, and Chamberlain remotes all use one of those two batteries. If neither the remotes nor the wall button work, the opener may have lost power. Which leads to the next check.
4. Tripped Breaker or Unplugged Opener
Look at the ceiling. The opener is plugged into an outlet near it. Storms, surges, and outlets that quietly trip are common. Find the breaker labeled "garage" or "garage door" in your panel and flip it off, then on. Then check the opener outlet. If the opener has a courtesy light and the bulb is dark when you pull the manual release rope or press the wall button, the opener has no power.
5. Broken Torsion Spring (Do Not Force It)
If the door is heavy when you try to lift it manually (after pulling the release rope) and you hear a loud bang earlier in the day that you brushed off, you almost certainly have a broken torsion spring. Look up at the bar above the door. If you see a clean break or a gap of two to three inches in the spring coil, that is the diagnosis. Do not run the opener. The opener cannot lift a door without spring assistance. Forcing it burns out the motor, bends panels, or worse. Read more about how springs fail in our post on how garage door springs work, and call us for garage door spring repair in Brunswick.
6. Broken or Off-Track Cable
If one side of the door is hanging lower than the other and the door is tilted, you likely have a broken lift cable. The cable is the steel rope that connects the bottom of the door to the spring drum. Once one cable snaps, the other side keeps lifting and the door binds in the tracks. Like a broken spring, this needs a pro. Forcing the door causes panel damage and can pull the entire track off the wall.
When To Call Us
If you have ruled out sensors, release rope, battery, and breaker, and either the door feels heavy or looks crooked, call us at (912) 209-4079. We cover Brunswick, St. Simons, Jekyll Island, and the entire Coastal Georgia and Northeast Florida corridor with same-day service most days. Most spring and cable repairs take under two hours, and we carry the standard residential parts on every truck. See our full garage door repair page for what we fix and what it usually costs.