What was found
FLIGHT 1704, ENROUTE HNL-OGG/AIR TURNBACK DISCREPANCY. NO PRESSURIZATION ON CLIMB OUT, DUCT TEMP OVER 50 DEGREES C. AIRCRAFT WAS RETURNED TO HNL, NO EMERGENCY DECLARED. LANDED WITHOUT INCIDENT. MAINTENANCE DEFERRED. MAINTENANCE REPLACED THE AIR CYCLE UNIT AND TIC VALVE. PRESSURIZATION TEST AND OPS CHECKS GOOD. DEFERRAL CLEARED. AIR CYCLE UNIT PN 2205120-1 SN 517, TIC VALVE PN 2214805-2.