As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O WITH GEAR HANDLE UP, UNSAFE GEAR LIGHTS ILLUMINATED AND STEADY HORN. REFERRED TO ABNORMAL PROCEDURE 6.2.67 AND RAN PROCEDURE, RETURNED TO LAND. REMOVED AND REPLACED NLG LOCK SWITCH AND LANDING GEAR ACCESORY UNIT AS PRECAUTION.