What was found
NOSE LANDING GEAR UNSAFE LIGHT REMAINED ON AFTER GEAR RETRACTION. CREW EXTENDED GEAR, DECLARED AN EMERGENCY, AND PERFORMED FLY-BY OF TOWER TO DETERMINE IF GEAR WAS DOWN AND LOCKED. FLIGHT WAS RETURNED TO MEM AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND CANNON PLUG P1-1157 TO DOWN AND LOCK SENSOR BROKEN. REPLACED PLUG. BITE CHECK FAULTED DOWNLOCK SENSOR. OPERATIONAL CHECK NORMAL. AIRCRAFT RETURNED TO SERVICE.