As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OVSP SYSTEM 1 FAILED DURING START RUN-UP. MAINTENANCE ARRIVED AND PULLED CB AND CAUTION LIGHT WAS STILL ILLUMINATED AFTER RESETTING CB. DURING TROUBLESHOOTING, FOUND #1 ENGINE OVERSPEED SENSOR BAD. PINS 1-2 OP AND PINS 4-5 HIGH RESISTANCE. REMOVED AND REPLACED #1 OVERSPEED SENSOR IAW 77-14-00-900-802-A01.