As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN PRESSURE CONTROL FAILED, SELECTED MANUAL. PERFORMED BIT CHECKS ON BOTH CONTROLLERS, BOTH SHOWED CONTROLLER FAILURES. CHECKED MANUAL OPS OF OUT FLOW VALVE, OPERATIONAL CHECKS GOOD. DEFERRED BOTH AUTO PRESS CONTROL SYSTEMS PER MEL 21-24B.