As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACTUATOR CAUTION APPEARED PRIOR TO TAKEOFF AND WOULD NOT EXTINGUISH. DURING TROUBLESHOOTING, FOUND PIN 17 (YAW INVAL VOLTAGE OUT) OF AFCS TEST PORT HAD NO VOLTAGE PRESENT. PIN A AT YAW SEMA HAD VOLTAGE IN. REMOVED AND REPLACED SEMA ACTUATOR IAW AMM 67-20-00. MTP MOC SUCCESSFULLY COMPLETED.