As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE TWO FLAPPER VALVES THAT STOP AIR FROM EXITING TO ENGINE BROKE LOOSE AND LODGED IN DUCT WORK. VALVES MIGRATED TO THE END OF DUCT AND SLOWED THE FLOW OF PRESSURE AIR TO THE AFT CABIN AND ROUTED ALL TO THE COCKPIT CAUSING TEMPERATURE TO BE VERY HOT IN COCKPIT.