As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT HAD RUDDER CONTROL PROBLEMS. THE YAW DAMP COMPUTER AND SERVO WERE BOTH SENT OUT FOR REPAIR AND TESTING. THE COMPUTER WAS RETURNED FROM REPAIR WITH NO FAULT FOUND. THE SERVO WAS RETURNED FROM REPAIR WITH BEARINGS AND DRIVE TRAIN CLEANED AND GREASED. (M)