As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT, AUTO PRESSURE CONTROL PRIMARY AND STANDBY LOCKED OUT. ACCOMPLISHED AN UNSCHEDULED LANDING. ACFT WAS INSPECTED AND THE AUTO PRESSURIZATION SYS WAS DEFERED IAW MEL 21-24, CAT C. ACFT DEPARTED, NO FURTHER DISCREPANCIES REPORTED ON THIS SYS. SYSTEM RTS WAS ACCOMPLISHED AND AN AUTO PRESSURE CONTROLLER WAS REPLACED.