As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GNDED. ACFT DID NOT DEPRESSURIZE ON SCHEDULE AT 8200 FT. SAFETY VLV OPENED & ACFT DEPRESSURIZED. BOTH SYS 2 THEN SYS 1 FAILED OUTFLOW VLV IAW 21-31-51-400-001A. OPERATIONS TESTED GOOD IAW MM 21-31-10-710-002A & 21-31-00710-003A.