As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW CREW REPORTED CABIN FAILED TO PRESSURIZE. RETURNED DFW WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED COMPRESSOR INLET AND OUTLET PRESSURE SWITCHES FOR LEFT HAND SIDE AND RIGHT PACK TEMPERATURE CONTROL VALVE. VAL5425. SYSTEM GROUND CHECK NORMAL OPERATION. (CLOSED)