What was found
ON FINAL APPROACH TO MSN PILOT REPORTED RECIEVING SPOILER AND SPEEDBRAKE SYSTEM FAIL INDICATIONS. AFTER LANDING COMMANDED SPEED BRAKES TO LIFT DUMP MODE BUT NOTED ONLY R/H WING PANELS EXTENDING. NOTED LOUDER THAN NORMAL NOISES WHEN CONDUCTING POST-LANDING SPOILER SYSTEM BIT TEST. DURING TROUBLESHOOTING PROCEDURES FOUND LT WING ROLL/SPOILER ACTUATOR E2 VOLTAGE READINGS FLUCTUATING BETWEEN -4.08 V AND -6.74 V. REPLACED L/H ROLL/SPOILER ACTUATOR (HBC P/N 390-381007-0003)WITH A REPAIRED ACTUATOR, OPERATION AND VOLTAGE READINGS WITHIN SERVICE LIMITS. RECOMMEND MANUFACTURER'S SERVICE FACILITY INVESTIGATE REMOVED UNIT AT TEARDOWN TO DETERMINE IF FAILED FROM NORMAL WEAR, AND INVESTIGATE WHETHER ACTUATOR UNITS NEED TO HAVE A RECOMMENDED CALENDAR OR TIME-LIMITED TBO.