As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT, AIRCRAFT WAS UNABLE TO MAINTAIN PRESSURIZATION. AIRCRAFT RETURNED AND MADE AN UNEVENTFUL LANDING. MAINTENANCE REMOVED AND REPLACED THE CABIN PRESSURE CONTROLLER. BITE AND OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.