As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT DURING FLIGHT THAT THE AMBER "LEFT GENERATOR OFF" WARNING ANNUNCIATOR ILLUMINATED. NO FREQS OF VOLTS INDICATED. THE CHECKLIST PROCEDURES WERE FOLLOWED BUT THEY WERE UNABLE TO RESET THE GENERATOR. THE FLIGHT RETURNED FOR LANDING AND REPAIRS. TROUBLESHOOTING FOUND THAT THE STARTER/GENERATOR WAS DEFECTIVE. THE UNIT WAS REMOVED AND REPLACED WITH OVERHAULED UNIT. THE AIRCRAFT WAS RETURNED TO SERVICE.