Garage Door Opener Just Buzzes — What Does That Mean?

Two likely culprits

If the motor hums but the trolley doesn't move, the gear assembly is stripped — common on chain-drive openers after 10+ years. A replacement gear kit is an inexpensive part.

If the motor hums then clicks off, the start capacitor is dead. A tech can usually swap it quickly.

Worth fixing or replace?

If your opener is over 12 years old, replace it. New belt-drive units are dramatically quieter and include modern safety features.