What was found
UNABLE TO ADEQUATELY CONTROL CABIN TEMP AFT OF ROW 20 WITHOUT MOVING CONTROL. PAX COMPLAINED OF EXTREME HOT AND COLD OSCILLATION. DUPLICATED DEFECT. ACCOMPLISHED FIM 21 61/863. FOUND AFT CABIN TEMP SENSOR DIRTY. REPLACED FILTER AFT CABIN REF MM 21 61 00. AFT CABIN TEMP SELECTOR OPS CHECK NORMAL, TEMP IS CONTROLLABLE. ALSO PERFORMED LT TEMP CONTROL BITE CHECK, CHECK GOOD. NO HISTORY 60 DAYS & SEAMC NOTIFIED.