As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS REPORTED THAT UPON CLIMBING THE AIRCRAFT FAILED TO PRESSURIZE AND THEY THEN RETURNED TO FMN. MAINTENANCE OPERATIONALLY CHECKED THE SYSTEM ON THE GROUND WHICH WAS GOOD PER MM 21-30-00. OPERATIONAL CHECK FLIGHT WAS PERFORMED AND WAS SATISFACTORY.