What was found
DURING CLIMB, THE FLIGHT CREW HAD DIFFICULTY PRESSURIZING THE AIRCRAFT IN AUTO AND A BURNING SMELL EMITTED FROM ROW 24. CABIN PRESSURIZATION WAS CONTROLLED MANUALLY AND AIRCRAFT RETURNED TO HNL AND LANDED WITHOUT FURTHER INCIDENT. REPLACED ZONE 3 TRIM AIR DUCT UNDER FLOOR AT ROW 24 RIGHT, CABIN PRESSURE CONTROLLER, AND NR 2 AIR CYCLE MACHINE TURBINE BYPASS VALVE. OPERATIONAL CHECK GOOD.