As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, LOUD NOISE FROM ENGINE COMPARTMENT FOLLOWED BY VIBRATION AND LOSS OF PRIMARY ELECTRICAL POWER. UPON INSPECTION, ONE SEGMENT FROM COMMUTATOR WAS MISSING AND AFT END OF GENERATOR AND BRUSHES HAD SUSTAINED HEAVY DAMAGE. AFTER REPLACEMENT WITH OVERHAULED UNIT, NO ABNORMALITIES WERE NOTED.