As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED UNABLE TO PRESSURIZE AIRCRAFT, SKIN OUTLET VALVE SHOWS FULL OPEN. *S/D* AVIONICS EQUIPMENT VENTILATION COMPUTER SKIN AIR OUTLET VALVE FAILED TO CLOSE AT TAKEOFF. DIFFERENTIAL PRESSURE COLLAPSED DUCTING. DUCTING AND VALVE REPLACED.