As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER THE PILOT SELECTED GEAR UP THE NOSE GEAR "DOWN" LIGHT REMAINED ILLUMINATED. CREW CONTINUED TO A MAINTENANCE BASE AND COMPLETED A MANUAL EXTENSION AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NOSE LANDING GEAR DOWN LIMIT SWITCH CONTAMINATED WITH ICE. SWITCH REPLACED AND AIRCRAFT RETURNED TO SERVICE. NOTE ALL OTHER AIRCRAFT IN FLEET HAD THE LANDING GEAR SWITCHES CLEANED AND LUBRICATED AS A PRECAUTIONARY MEASURE.