DIAGNOSIS The motor is running but the drive system is disengaged. The most common cause is a broken or stripped plastic drive gear inside the motor unit.
FIX This requires opening the motor unit. Disconnect power. Remove the cover. Inspect the main plastic gear (the worm gear) that connects the motor shaft to the chain drive. Look for missing teeth or a sheared center hub. The gear is designed to fail first to protect the motor. Replacement gear kits (Genie part #A70-A) are available.
IF THAT DIDN'T WORK The clutch may have failed. With power disconnected, try manually pulling the release handle (the red cord). If the chain moves freely but the motor still hums when engaged, the clutch mechanism inside the gear assembly is faulty.
HEADS UP When replacing the plastic gear, thoroughly clean out all plastic debris from the gearbox. Lubricate the new gear and metal worm shaft with the grease provided in the kit. Do not use other lubricants.