As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED TO THE FIELD DUE TO BEING UNABLE TO PRESSURIZE. RECONFIGURED AFT OUTFLOW VLV TO 0.07 OPEN, PRESSURIZED ACFT TO 1.5 PSID AMM 05-51-24 REFERS. ALL CHECKED GOOD. ALTHOUGH NO DEPRESSURIZATION OCCURRED, PERFORMED CONDITIONAL GVI DESCRIBED AT 05-51-12 AS PRECAUTION, NOTHING ABNORMAL FOUND.