As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE FLIGHT 2039 THE CREW REPORTED ON TAKEOFF FROM CLE THE AIRCRAFT WOULD NOT PRESSURIZE. TRIED MANUAL MODE WITHOUT SUCCESS. THE AIRCRAFT RETURNED TO CLE AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND REPLACED THE ELECTRO PNEUMATIC OUTFLOW VALVE AND REMOVED DEBRIS FROM MANUAL CONTROLLER VENT SCREEN. OPERATIONAL CHECKS WERE GOOD.