As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WOULD NOT PRESSURIZE WITH PRIMARY SYSTEM AFTER TAKEOFF. SWITCHED TO STANDBY AND SYSTEM WORKED NORMALLY. TRANSFER LOCKOUT AND STANDBY ON LIGHTS ILLUMINATED. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. REPLACED THE PRIMARY CABIN PRESSURE CONTROLLER. OPERATIONAL CHECK OK ON GROUND. AIRCRAFT RETURNED TO SERVICE.