As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF NR 4 ENGINE FIRE WARNING ILLUMINATED INTERMITTENTLY, SHUT DOWN ENGINE AND RETURNED TO KMIA AFTER FUEL DUMPING. OVERWEIGHT LANDING IN KMIA, SMOOTH LANDING. REMOVED AND REPLACED AMPLIFIER (POSITION NR 4) IN ACCORDANCE WITH MM 26-10-4 AND REMOVED & REPLACED FIRE LOOP AFT LOOP POSITION IN ACCORDANCE WITH MM 26-10-0 CHECKED SYSTEM OK IN ACCORDANCE WITH MM 26-10-0 AND MM 71-00.