As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 3109, THE CREW REPORTED AFTER T/O THE GEAR STARTED TO RETRACT, GOT AMBER THEN RED INDICATIONS WITH LANDING GEAR LEVER DISAGREE MESSAGE. THE GEAR STOWED AT 1300 FT. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT OPERATIONALLY CHECKED THE EXTENSION & RETRACTION SYSTEMS WITH NO DEFECTS NOTED, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.