As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - WHILE LANDING LANDING GEAR DOWN INDICATION LIGHTS CYCLED ON AND OFF WITH ASSOCIATED WARNING HORN. INDICATOR PIN WAS UP. ACCOMPLISHED GO-AROUND. LANDED DFW WITHOUT INCIDENT. AIRCRAFT TAKEN OUT OF SERVICE FOR EVALUATION. FOUND DOWN LOCK SENSOR CONNECTOR PIN PUSHED BACK. INSERTED AND LOCKED DOWN LOCK SENSOR CONNECTOR PIN. SYSTEM GROUND CHECKED NORMAL OPERATION.