As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED PRESSURIZATION PROBLEMS WITH RIGHT PACK AND LEFT PACK ON MEL. FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED TEMPERATURE CONTROL VALVE. FOUND BROKEN GROUND TO PACK OUTLET TEMP SENSOR AND REPLACED SENSOR.