As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH FLIGHT 2072, PILOT REPORTED THAT THE LEFT MAIN LANDING GEAR DID NOT RETRACT. THE AIRCRAFT RETURNED TO IAH AND LANDED WITHOUT INCIDENT WHERE MAINTENANCE REMOVED AND REPLACED THE LEFT MAIN GEAR UPLOCK BOX. THE LANDING GEAR EXTENSION/RETRACTION SYSTEM WAS OPERATIONALLY CHECKED AND NO DISCREPANCIES WERE FOUND.