As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AIRCRAFT RUN-UP PROCEDURES PILOT ENGAGED GOVERNOR SWITCH INCREASED THROTTLE TO 832% FOR GOVERNOR TO TAKE OVER. GOVERNOR FAILED TO ENGAGE, AIRCRAFT SHUT DOWN NORMALLY. MECHANIC PERFORMED TROUBLESHOOTING PROCEDURES FOUND GOVERNOR CONTROLLER PN D278-1 TO BE THE CAUSE. REPLACED UNIT WITH OVERHAULED UNIT, SYSTEM CHECKS COMPLETED WITH DO DEFECTS NOTED.