As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE NLG WOULD NOT RETRACT AFTER TAKEOFF FROM IAH. THE FAILURE WAS ACCOMPANIED BY ILLUMINATION OF THE NLG UNSAFE LIGHT AND VIBRATION FROM THE NOSE GEAR AREA. THE AIRCRAFT WAS RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. THE NLG LOCK ACTUATOR AND LOCK MANIFOLD VALVE WERE REMOVED AND REPLACED IAW MM 32-33-21 AND 32-33-31. AN OPERATIONAL TEST WAS PERFORMED IAW MM 32-33-00 AND SYSTEM CHECKS WERE NORMAL.