What was found
VENTRAL RUD FAIL WHITE CAS: DURING ENROUTE CLIMB AT ABOUT FL350 WE GOT AN INTERMITTENT VENTRAL RUD FAIL WHITE CAS WHICH THEN STAYED ON PERMANENTLY UNTIL LANDING. WE LEVELED OFF AT FL380 AND MAINTAINED APPROXIMATEY 210KTS INDICATED FOR THE REST OF THE FLIGHT. REMOVED AND REPLACED WITH C/P REPAIRED SERVO MOTOR IAW AMM 22-11-11. OPS CHECK COMPLETED OK PERFORMED SERVO LOG DOWNLOADS AND SENT TO CONTACT CENTER FOR REVIEW. REF AMM 31-41-05 CONTACT CENTER RESPONDED BACK THE FOLLOWING "PERFORM THE ELECTRICAL CHECKS GIVEN ON THE SUBTASK 810-110-A & SUBTASK 813-138-A, IF NO DISCREPANCY IS NOTED ON THE CHECKS, REPLACE AUTOPILOT VENTRAL-RUDDER SERVO ACTUATOR". REMOVED CONNECTOR J1415 AND CHECK POWER AT PINS N AND P. 28VDC