As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORT; LANDING GEAR WOULD NOT RETRACT. AC RETUNED TO FIELD. MAINTENANCE REMOVED AND REPLACED THE NLG UPLOCK PROXIMITY SWITCHES (2 EA). LANDING GEAR EXTENSION AND RETRACTION CHECKS WERE PERFORMED AND AIRCRAFT WAS RETURNED TO SERVICE.