What was found
(CAN) ELEVATOR TRIM WOULD NOT FUNCTION AT TOP CLIMB. ELECTRIC TRIM MOTOR APPEARED TO FUNCTION NORMALLY BUT NO TRIM CONTROL MOVEMENT AVAILABLE. MANUAL TRIM DID NOT ACTUATE CONTROL SERVICE. MANUAL TRIM WHEEL WOULD ONLY FREE WHEEL, NO TRIM CONTROL AVAILABLE. AIRCRAFT RETURNED TO DEPARTURE AIRPORT. AOG TEAM SENT TO REPAIR AIRCRAFT. TRIM CABLE FOUND TO HAVE FAILED. ONE SIXTEENTH CABLE FRAYED AND BROKEN IN AREA OF TRIM SEREVO TRAVEL. CABLE REPLACED AND ELECTRIC TRIM SERVO REPLACED. BOTH PARTS SENT FOR NSPECTION. FLEET AIRCRAFT ALL INSPECTED (LIMITED TO KING AIR C90 WITH " CENTURY FOUR" AUTO PILOT SYSTEM)CABLE DATA- ORGINAL MANUFACTURER UNKNOWN-11393 CYCLES-7603.6 HRS