Opener runs but the garage door does not move
The motor sounds normal and the door stays where it is. Usually that means something between the opener and the door has let go, and a two-minute look tells you which.
The motor runs its full cycle and the door has not moved. That points at the drive train between the opener and the door, not the electronics.
The release cord
Most overhead openers have a release cord, usually red, hanging from the trolley on the rail. Where the motor is mounted on the wall beside the springs, there is no rail and no trolley, and the release sits on the door itself. It disconnects the door for hand operation, and it gets pulled by accident more than anything else on the door. Watch the rail while someone presses the button. If the carriage slides along the rail and the bent arm bolted to the door stays put, the trolley is disengaged.
Before you reconnect the trolley, look at the spring above the door. With a broken spring a double door can weigh a couple of hundred pounds, and the release puts that weight in your hands. See our broken spring page.
A stripped drive gear
Chain and belt openers pass the motor's output through a plastic gear inside the head. That gear is meant to be the weakest link, so it goes before the motor does. Once the teeth strip, the motor spins with nothing behind it and the sprocket never turns. The sound is high and smooth with no load on it, and there is often gray plastic dust on the floor below. Weeks of grinding beforehand were the warning. See openers.
A broken chain, belt or shaft
A snapped chain, or one off its sprocket, looks the same from the doorway. Look up. A dropped chain hangs in a loop across the top of the door, and a parted belt is plainer still. Inside the head, the shaft carrying the drive sprocket can snap or lose its key, so the sprocket turns while the chain sits still. Above the door, the steel torsion shaft carries the drums the lift cables wind onto. If that shears, one side rises and the other stays put. The door racks and the cable on the dead side goes slack. Stop there. A racked door is on its way off the track and still under load. Read off track or cable damage and keep everyone clear.
How this differs from a spring failure
A spring failure sounds different. The opener strains instead of running free, the door lifts a few inches and stops, or it starts and reverses back down. Motor noise with no strain behind it is a drive train fault.
Never put hands near a snapped torsion spring or try to unwind one. See spring repair.
Getting it diagnosed
The inspection and estimate are free whether or not you approve the work, and whatever we install, from a gear kit to a whole opener, is listed on the invoice with its specification. You can ask about financing.
Book a free estimate anywhere in Los Angeles County, or see what we repair. Other symptoms sit under garage door problems. If the opener has been patched twice and the door is tired, preview a new door on your own frontage with the visualizer.
Get the door looked at.
The price is written down before anything is touched, and it holds. Nothing else is done without your say-so.