What was found
RIGHT A/C PACK RT ADVISORY AFTER T/O, UNABLE TO RESET WITH NON NORMALS CHECKLIST. RT CAC DEFLECTOR DOOR ACTUATOR FAILED MAINT MSG 21-61613. CHECKED CMCF AND MENTIONED MAINT. MESSAGE DISPLAYED. FOLLOWED FIM DMC-B787-A-21-50-F1-37A-421A-A AND SAME FAULT DISPLAYED. FOUND RT CAC DEFLECTOR DOOR RETRACTED ON ARRIVAL. RT CAC DEFLECTOR DOOR IN RETRACTED POSITION IAW MEL 2151Z. RT CABIN AIR COMPRESSOR DEFLECTOR DOOR INOPERATIVE IAW DEACTIVATED IN RETRACTED POSITION PER MEL 2151Z. DM ACCORDING TO THE FIM TASK ASSOCIATED WITH MX MSG 21-61613, POSSIBLE CAUSES ASIDE FROM WIRING IS THE DEFLECTOR DOOR ACTUATOR 78-2151-9-9002 OR PACK CONTROL UNIT 79-2151-9-0012. REMOVED RT CAC INLET DEFLECTOR DOOR ACTUATOR. IAW AMM 21-51-16-00A-520A-A. CHECKED WIRING BETWEEN ACTUATOR AND RT PACK CONTROL UNIT. IAW FIM 21-50-F1-37A-421A. FOUND NO ISSUES WITH WIRING. NEXT STEP OF FIM IS REPLACE DOOR ACTUATOR. REINSTALLED OLD ACTUATOR. IAW AMM 21-51-16-00A-720A-A. COMPLIED WITH DDG 21-51-02A.