What was found
"FLIGHT CONTROL SYS" STATUS MESSAGE IS DISPLAYED. FAILS ACE MONITOR GROUND TEST MSG27-13007. REPLACED RT ACE-NO HELP. PERFORMED ALL STEPS FOR FIM 27-02 TASK 809 AND IT STILLS FAILS GROUND TEST. REPLACED R-ACE WITH A KNOWN GOOD ACE FROM AC2982. NO HELP, REINSTALLED OLD UNIT, TRIED DICON APU AND MAIN BATTERY, NO HELP FOLLOW MT27-016-R1 UP TO STEP 11, PG 4. REPLACED ARINC-629 COUPLER B27132 (ACE-R). FLT CONTROL SYS" STATUS MSG. CLEARED & PRIM FLT CONTROL SYS - ACE MONITORS GRD TEST - PASS. ALSO REPLACED CTR-ACE.