As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW INFLIGHT - ON APPROACH MAIN LANDING GEAR INDICATION WAS GREEN FOR ABOUT TWO SECONDS AND THEN WENT TO RED. HYDRAULIC PRESSURE NORMAL. RECYCLED GEAR AND ABORTED APPROACH. LANDING GEAR GREEN LIGHTS ON THIRD TRY LANDING GEAR INDICATION WAS GREEN. LANDED DFW WITHOUT INCIDENT. REPLACED NOSE GEAR LOCK SENSORS. SYSTEM GROUND CHECKED NORMAL OPERATION.