As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE N AMBER CAS: ENROUTE FL410 LOUD BANG FOLLOWED BY GEAR DISAGREE N AND SHADED NOSEGEAR. FELT NOSEGEAR WAS PARTIALLY DOWN. AT 180KIAS AT APPROX FL300 FELT ANOTHER JOLT AND ALL INDICATIONS WERE THE NOSEGEAR RETURNED TO THE UP POSITION. RECEIVED 3 GREEN DN ON APPROACH, LANDED AND TAXIED NORMALLY. CORRECTIVE ACTION; REMOVED AND REPLACED NLG UPLOCK ACTUATOR IAW CESSNA 680A MM 32-32-15. OPS CHECKS GOOD.