What was found
FLIGHT 9212, AFTER TAKEOFF LANDING GEAR RETRACTED NOSE LANDING GEAR A SYSTEM (B) LIGHTS AND B SYSTEM (B) LIGHTS REMAINED ILLUMINATED CYCLED LANDING GEAR INDICATION REMAINED THE SAME. RETURNED TO DEPARTURE, LANDED WITHOUT INCIDENT. REPLACED B SYSTEM DOWNLOCK PROXIMITY SENSOR HARNESS, OPERATIONAL CHECK NORMAL.