As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT AFTER TAKEOFF AND DURING CLIMB THAT THE ACFT WOULD NOT PRESSURIZE. THE ACFT RETURNED TO BASE WHERE MX INVESTIGATED THE PROBLEM. IT WAS FOUND THAT THE PRESSURIZATION CONTROLLER HAD FAILED. THE PART WAS CHANGED WITH A SERVICEABLE REPAIRED UNIT AND THE SYS WAS FUNCTION CHECKED SERVICEABLE.