You press the remote from the driveway and hear the motor hum overhead, a steady drone with no movement behind it. The door stays shut.
Press the button and the opener hums for a second, then quits. The trolley is jammed hard against a bolt at the very end of the rail near the motor and will not budge in either direction.
Someone tightened the belt last month to stop the sag. Now the opener sounds like a chain drive, the motor labours on the way up, and the whole rail vibrates under the ceiling.
Press the button and the motor hums, but the door stays exactly where it is. Under the housing there is a dusting of white plastic shavings, the sign of a stripped drive gear, and this is the second time it has happened.
Someone backed the car in a little too far, a bin or a bicycle brushed the track, and since then the door starts to close and comes back up. One sensor now sits at a slightly different angle from the other.
You bought a new remote at the hardware store, followed the little leaflet twice, and the opener light never blinked. The old remote still works.
Your daughter gets home from school an hour before anyone else. She has lost two house keys this year, and the garage keypad code has been shared with half her class.
A previous owner knotted the release cord around the rail and stacked storage shelves right beneath it. You only discovered this in the dark, with the power off, a flashlight in your teeth and a car that needed to be somewhere.