What was found
AFTER ENG SHUTDOWN RT PACK ACM FIM DMC-B787-A-21-50-F2-69A-421A-A, FOLLOWED, MAINT MSG 21-65213 LATCHED. RAN SYSTEM TEST IAW FIM AND RT ACM HAS FAILED. STARTING MEL PROCEDURE 2152DB DEACTIVATED RT PACK ACM IAW DDG 21-52-03, AMM DMC-B787-A-21-00-00-58A-721B-A. MX CONFIRMED NO ACRID ODOR PRESENT ONCE ACM LOCKED OUT & PACK OPERATED. COMPLIED WITH MEL 2152DB. R & R RT PACK ACM IAW AMM DMC-B787-A-21-52-02-02A-520A-A, & DMC-B787-A-21-52-02-02A-720A-A. OPS CHKD GOOD. GROUND TEST PASSED. LEAK CHKD GOOD. OK TO CONTINUE IN SERVICE. REVERSED MEL. NO STATUS OR MMSG'S.P