What was found
FLL FLT 365 EN-ROUTE CLT TO FLL - AFTER TAKE-OFF, AND UPON GEAR RETRACTION, RECEIVED EICAS MESSAGE "GEAR DOOR" WITH THE GEAR HANDLE UP. ALSO, THE LEFT GEAR DOOR LIGHT ILLUMINATED. HOWEVER, THE GEAR AMBER LIGHT AND ALL GREEN LIGHTS WERE EXTINGUISHED. THE CREW CYCLED THE GEAR, AND ALL INDICATIONS RETURNED TO NORMAL. FLIGHT CONTINUED TO FLL AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE LEFT MAIN GEAR UPLOCK OPERATED SEQUENCING VALVE. OPERATIONALLY AND LEAK CHECKED OK.