As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE NR 3 ENGINE FIRE WARNING SYSTEM INDICATED HIGH AND THE FAULT LIGHT AND DETECTION LIGHT ILLUMINATED. DISCHARGED FIRE BOTTLE AND SHUT DOWN THE ENGINE AS A PRECAUTION. AIRCRAFT RETURNED TO LAX AND LANDED WITHOUT INCIDENT. RESEATED AND CLEANED THE CONNECTORS ON THE NR 3 ENGINE LOOP CONTROL CARDS AND WARNING CARDS, OPERATIONAL CHECK GOOD.