What was found
UNABLE TO CONTROL CABIN TEMPRATURE PROPERLY. FWD AND AFT CAB KNOBS IN FULL COLD DRIVE SUPPLY DUCTS TO 10 DEG, IF MOVE THEM TO 12 O`CLOCK POSITION, SUPPLY DUCTS STAY AT 10 DEG C, MUST MOVE THEM TO 1 O`CLOCK POSITION FOR TEMP TO INCREASE. IN "FIXED CABIN TEMP MODE", ALL 3 OFF, LEFT PACK READ 30 DEGREES INSTEAD OF 24 DEGREES IAW SYSTEMS MANUAL AND RT PACK READS 24 DEGREES INSTEAD OF 18 DEF IAW SYS MANUAL. ACFT GROUNDED. FOUND FWD & AFT CABIN SENSORS FILTERS CLOGGED. CLEANED FWD & AFT CABIN SENSORS & REPLACED FWD & AFT CABIN SENSOR FILTERS. OPS CK GOOD. REF AMM 21-61-10, 21-61-06, 21-61-00-700-807-002.