Diagnosis
The motor clutch is disengaged. This is a safety feature to prevent burnout if the door is jammed or too heavy.
How to Fix It
Disconnect the door from the trolley by pulling the red emergency release cord. Manually lift the door halfway. It should move smoothly. If it's very heavy, the springs are bad—call a door tech. If it's smooth, reconnect the door to the trolley and try the opener.
If That Didn't Work
The internal clutch mechanism in the motor head may be faulty. You'll need to replace the motor unit gear assembly, part # 41A4275.
Heads Up
That humming is the motor trying. Do not press the button repeatedly. You can overheat the windings. Wait a full minute between attempts.