As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIRE DETECTION AND NACELLE FIRE DETECTION FAULT LIGHT ILLUMINATED. NR 1 ENGINE TEMPERATURE AND "B" IN RED BAND. INSPECTED NR 1 ENGINE FIRE LOOPS. REPOSITIONED ELEMENT ON UPPER "B" LOOP. PERFORMED OPERATIONAL CHECK OF NR 1 ENGINE FIRE DETECTION SYSTEM IN ACCORDANCE WITH B747 MAINTENANCE MANUAL 26-11-00. NO DEFECTS NOTED.