As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE FLIGHT 3309 THE CREW REPORTED THE LANDING GEAR WOULD NOT RETRACT AFTER TAKEOFF FROM CLEVELAND. THE AIRCRAFT RETURNED AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE LANDING GEAR ELECTRONIC UNIT. OPERATIONAL CHECKS WERE GOOD. THE AIRCRAFT WAS RELEASED FOR SERVICE.