As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR HORN SOUNDED AND 3 UNSAFE LIGHTS ILLUMINATED. FLIGHT CREW ELECTED TO RETURN TO BASE AND CREW OBTAINED 3 SAFE LANDING GEAR DOWN LIGHTS. AIRCRAFT FERRIED TO ATL. MAINTENANCE BASE FOR JACKING OF AIRCRAFT AND GEAR SWING AND REAIRS AS NECESSARY. REPLACED FLAP SWITCH AND PERFORMED GEAR SWING IAW MM 32-00 AND 27-00, OPS CHECKED GOOD.