What was found
AFT CABIN TEMP CONTROL SYSTEM INOP ( CABIN COMPT TEMP CONTROL SYSTEM / ALL CARGO CONFIGURATION )(<P>TRANSFERRED TO MEL 21-61-01-02, CAT C, DUE DATE 17 SEP21. MDDR 153159. MCC NOTIFIED. PLACARD INSTALLED. LP 1407696: T/S PER FIM 21-60 FT 804 TO STEP 52 SHEET 5, " TRIM VALVE " MSG ON ZONE TEMP BITE, TABLE B SHEET 2. PERF CONT CHECK FROM CONNECTOR D770B PINS C13,C15 TO PINS 2.1 CONNECTOR D700 CHECK GOOD, SWAPPED FWD AND AFT TRIM AIR VALVES IAW AMM 21-61-02. REMOVED AND INSTALLED FWD AND AFT TRIM VALVES TO ORIG POSITIONS. IAW AMM 21-61-07. REMOVED AND REPLACED AFT TRIM CONTROL VALVE IAW AMM 21-61-07. OPS CHECK GOOD. THIS CLEARS DMI 153159. MCC NOTIFIED. PLAC REMOVED.