As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - FLT 1431 - ON CLIMB-OUT FROM MIA, CREW WAS UNABLE TO PRESSURIZE AIRCRAFT OR CONTROL CABIN IN STANDBY OR MANUAL MODES. FLIGHT RETURNED TO FIELD AT MIA AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE AFT OUTFLOW VALVE PER MM CHAPTER 21. OPERATIONAL CHECK GOOD. (M)