As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON PREPARATION FOR DESCENT, CABIN PRESSURIZATION CONTROLLER RATE WAS ADJUSTED. AFTER ADJUSTMENT WAS MADE CABIN PRESSURE INCREASED TO MAXIMUM DIFERENTIAL AND WAS UNCONTROLLABLE AND NONRESPONSIVE TO ANY FURTHER ADJUSTMENTS TO THE CONTROLLER. CONTROLLER REPAIRED.