As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT FAILED TO PRESSURIZE AFTER TAKEOFF. RETURNED TO FIELD. LANDING UNEVENTFUL. FOUND AFT CARGO BULKHEAD BLOW OUT PANEL DISLODGED REINSTALLED BLOW OUT PANEL IAW AMM TASK 25-52-07-400-802. GROUND RUN ACFT FOR GOUND PRESSURIZATION CHECK IAW AMM TASK 21-00-00-863-801. OPS TESTED, PRESSURIZATION NORMAL. RETURNED TO SERVICE.