As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) 5.9 HOURS AFTER A SCHEDULED BRUSH CHANGE A LOUD "HUM" WAS DETECTED ON NR 2 GENERATOR. THE HUM STOPPED WHEN THE GENERATOR WAS SELECTED OFF. THE STARTER/GENERATOR WAS REMOVED AND THE BELL HOUSING LEGS WERE FOUND TO BE SEPARATED FROM THE MOUNTING RING. THE STARTER/GENERATOR WAS REPLACED WITH A SERVICEABLE UNIT.