As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STARTER/GENERATOR WAS PURCHASED FROM DEHAVILLAND ZERO TIME NEW. AFTER 1211.5 FLIGHT HOURS OF OPERATION, STARTER/GENERATOR FAILED. TEAR DOWN REVEALED INSULATORS WERE MISSING FROM THE BRUSH HOLDERS. THIS CAUSED THE ARMATURE AND STATOR TO SHORT CIRCUIT RESULTING IN STARTER/GENERATOR FAILURE.