As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 4966 - JFK - GEAR UNSAFE WARNING WHEN GEAR SELECTED DOWN FOR LANDING. ALL THREE GREEN LIGHT EXTINGUISHED. CFR EQP WAS CALLED OUT. CYCLED GEAR HANDLE SEVERAL TIMES, AND FINALLY DID ACHIEVE SAFE INDICATIONS. SAFE LANDING IN JFK. INSPECTED GEAR AND FOUND NO DEFECTS. PERFORMED GEAR SWING AND SYSTEM OPERATED NORMALLY. REPLACED LANDING GEAR CONTROL VALVE AS PRECAUTIONARY MEASURE.