As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - FLT 627 - UNABLE TO PRESSURIZE AIRCRAFT IN AUTO OR MANUAL DURING TAKEOFF. DUMPED FUEL AND RETURNED TO MIA WITHOUT INCIDENT. AIRCRAFT INVESTIGATED FOR DEFECTS. PRESSURIZATION NORMAL IAW MM 21-30-00. LUBED OUTFLOW VALVE AS PRECAUTIONARY. CHECKED NORMAL PER MM 21-30-00. (X)