As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT RETURNED TO FIELD WHEN AFTER TAKE-OFF THE GEAR FAILED TO RETRACT. MAINTENANCE INSPECTED THE SYSTEM AND REPLACED THE NOSE LANDING GEAR PROXIMITY SENSOR. THE OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.