What was found
(CAN) DURING LANDING GEAR `UP` SELECTION FOLLOWING TAKEOFF, THE NLG `RED` GEAR UNSAFE LIGHT REMAINED `ON`. CREW LOWERED THE LANDING GEAR BY ALTERNATE EXTENSION, WITH ALL LANDING GEARS INDICATING THREE GREENS GEAR SAFE, THE AIRCRAFT WAS RETURNED TO BASE WHERE A NORMAL APPROACH AND LANDING WAS CARRIED OUT WITHOUT INCIDENT. LINE MAINTENANCE INVESTIGATION IDENTIFIED FAILURE OF THE NLG SOLENOID SEQUENCE VALVE. AFFECTED VALVE WAS REPLACED AND FOLLOWING APPROPRIATE CHECKS IAW THE AIRCRAFT`S MM THE AIRCRAFT WAS RETURNED TO SERVICE WITHOUT FURTHER INCIDENT. (TC NR 20070921001)