What was found
ON APPROACH, LOWERED MLG, RECEIVED A "GEAR DISAGREE" EICAS MESSAGE. NO INDICATION ON NOSE GEAR. BOTH MAIN GEAR DOWN AND LOCKED GREEN INDICATION WITH AN AMBER DOORS LIGHT ILLUMINATED AS WELL AS AN AMBER GEAR LIGHT. COMPLETED A GO AROUND AND COMPLIED WITH QRH. CYCLED GEAR AND RECEIVED 3 GREEN DOWN AND LOCKED INDICATION. LANDING GEAR MONITOR STATUS MESSAGE. TROUBLE SHOT IAW FIM 32-30 803 AND REPLACED NLG DOOR OPERATED SEQUENCE VALVE, IAW MM 32-34-05-4. REPLACED NLG LOCK ACTUATOR IAW MM 32-34-02-4 AND PERFORMED EXT AND RET IAW MM 32-34-00-5 SYS, OPS CHECKED NORMAL.