For a few days there was a grinding sound whenever the door started moving. Now the motor spins freely and the door stays exactly where it is.
The door opens about a third of the way and stops. Turning the limit screw on the head has made no difference, and the trolley seems to sit in the wrong place along the rail when the door is fully closed.
The door used to glide up with a soft hum. Now there is a sharp clack every second or so, and if you stand underneath you can see the belt sagging below the rail and slapping it on the way up.
During the ice storm the power was off for two days. You came home in the dark, found the door dead, and had to climb out of the car to pull the red cord in the cold.
The small light on one of the sensors near the floor has gone dark, or it flickers when someone walks past the track. The other one glows steadily.
Someone in the family tried to add a remote, held the button on the ceiling unit a little too long, and now every remote in the house is dead at once. The wall control still moves the door.
One remote lives in a car you sold last spring. The other needs three presses from the driveway and its battery cover is taped on.
After a week of lifting the door by hand you pressed the button, hoping it would catch. Instead the motor grinds, the trolley thumps against the end of the rail, and the little lever that should snap back stays stubbornly upright.