What was found
DIFFICULT COOLING THE AFT CABIN DURING FLIGHT. EVEN WITH AFT CABINE TEMP SELECTOR NEARLY FULL COLD & SUPPLY DUCT TEMP INDICATING 10 C, F/A COMPLAINS OF VERY WARM AFT HALF OF CABIN. ACFT GROUNDED. PERFORMED A BITE CHECK OF THE CABIN TEMP CONTROLLER, OPS GOOD IAW FIM 21-61-00-810-801. REMOVED AND REPLACED THE TEMP FILTERS IN FWD AND AFT CABIN. CLEANED TEMP BULB OF DUST IAW AMM 21-61-06. RAN PACKS WITH APU, OPS GOOD.