As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) NR 1 DC GENERATOR FUNCTION CHECK FAILED DURING ENGINE RUNS. DC GENERATOR REPLACED. FURTHER ON, AN INSPECTION WAS C/O ON THE FAILED DC GENERATOR AND FOUND A SCREW HOLDING ONE OF THE TERMINAL CABLES CHAFED. THE INSULATION MATERIAL BENEATH THE PROTECTING COVER AS A RESULT THE CABLE TERMINAL MADE CONTACT WITH THE METAL COVER, PARTIALLY MELTED THE SCREW AND PRODUCED ARC.