What was found
AFTER TAKEOFF, DURING A TURN, RECEIVED AN AUTO PACK TRIP OFF LIGHT. DURING PROCEDURE THE OXYGEN MASK DROPPED ON AND START SOUND. PERFORMED TROUBLESHOOTING IAW AMM 21-31-00; 36-11-05 AND AMM 36-12-35. REPLACED THE VALVE, FLOW CONTROL VALVE, HIGH STAGE VALVE, BLEED AIR REGULATOR, PRESSURE REGULATOR, SHUTOFF VALVE, PRECOOLER CONTROL VALVE, AND PRESSURE REGULATOR.