As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT THE CABIN FAILED TO PRESSURIZE AFTER TAKEOFF. CREW ATTEMPTED MANUAL AND AUTO MODES WITH NO SUCCESS, AIRCRAFT RETURNED TO CMH AND LANDED WITHOUT INCIDENT. MAINTENANCE PERFORMED NUMEROUS OPS CHECKS OF THE CABIN PRESSURIZATION SYSTEM IN BOTH AUTO AND MANUAL MODES WITH EACH ATTEMPT SUCCESSFUL. NO DEFECTS WERE NOTED DURING ALL CHECKS THAT WERE PERFORMED.