What was found
F/A REPORTED DURING FLIGHT, MID CABIN HOT WITH BACK COLD AND FRONT COOL. ACFT GROUNDED. W/APU RAN BOTH PACKS 4 PLUS HOURS W/ MAIN CABIN TEMP SELECTORS AT VARIOUS SETTINGS. USING P5-17 CABIN TEMP INDICATOR, FOUND FWD AND AFT CABIN TEMPS, DUCT SUPPLY TEMPS MATCHED AT EACH TEMP SELECTOR SETTINGS. CABIN WALK THRU FOUND CABIN, MAIN, SAME TEMP THROUGHOUT LENGTH OF MAIN CABIN. PACK/ZONE TEMP. CONTROLLERS BITE TEST SHOWED NO FAULTS AND A "GO" EACH TEST. CLEANED MAIN CABIN TEMP FILTERS PRECAUTIONARY, OPS NORMAL REF 21-61-00, CABIN TEMP CONTROL AND INDICATOR OPS TEST.