As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT 15,000 FT WITH B LOOP SELECTED FOR NR 3 ENGINE FIRE DETECTION SYS, NR 2 ENGINE FIRE LIGHT ILLUMINATED AND BELL. ABNORMAL POM C/W AND NR 2 ENG SHUTDOWN. FIRE LIGHT NEVER WENT OUT AND BELL INTERMITTENT. FOUND DETECTOR LOOP NR M447 BAD. REMOVED AND REPLACED LOOP, RAN ENG AT T/O AND PART POWER. LOOP AND ENG RUN, CHECK NORMAL. LOOP (S/N 3386) OFF, (P/N 264101400).