As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED AIRCRAFT WOULD NOT PRESSURIZE AFTER TAKEOFF. AT 8000 FEET AFT GALLEY DOOR LIGHT ILLUMINATED. FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED OUTFLOW VALVE ACTUATOR ASSEMBLY. SYSTEM GROUND CHECKED NORMAL OPERATION.