As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN WOULD NOT PRESSURIZE AFTER TAKEOFF. FOUND CABIN AIR CONDITIONING VALVE TO BE STUCK IN THE CLOSED POSITION. VALVE WAS SET INT THE OPEN POSITION AND DEFERRED, APPROVED MEL. VALVE WILL BE REPLACED UPON PROCUREMENT OF SERVICEABLE PART. (K)