What was found
WHEN GEAR HANDLE WAS MOVED TO UP AFTER TAKEOFF, THE AMBER DOORS LIGHTS AND AMBER GEAR LIGHT REMAINED ILLUMINATED AND ALL GREEN LIGHTS WERE OUT. THE EICAS MESSAGE GEAR DISAGREE ALSO APPEARED. ALL LIGHTS WENT OUT AFTER APPROXIMATELY 45 SECONDS. MAINTENANCE FOUND THE NOSE GEAR RETRACT ACTUATOR AT FAULT. THE ACTUATOR WAS REMOVED AND REPLACED IAW MM 32-34-00, OPERATIONAL CHECKS WERE GOOD.