As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ONE DC GENERATOR FAILED IN-FLIGHT. MAINTENANCE PERSONNEL FOUND THE DC GENERATOR TO HAVE PREMATURE BUSH WEAR (75 PERCENT WORN). OVERHAULED BY A REPAIR STATION. CAUSE OF BRUSH WEAR NOT DETERMINED. BRUSH PART NUMBER NOT DETERMINED, SUSPECT DEFECTIVE BRUSHES OR IMPROPER INSTALLATION/OVERHAUL PROCEDURE.