What was found
AIRCRAFT RETURNED TO THE FIELD WHEN IT WAS UNABLE TO PRESSURIZE AFTER TAKEOFF. THE CABIN PRESSURE CONTROLLER FAILED. REPLACED PRESSURE CONTROLLER, TESTED NORMAL.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AIRCRAFT RETURNED TO THE FIELD WHEN IT WAS UNABLE TO PRESSURIZE AFTER TAKEOFF. THE CABIN PRESSURE CONTROLLER FAILED. REPLACED PRESSURE CONTROLLER, TESTED NORMAL.