As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT DURING THE PREFLIGHT INSPECTION THE NR 2 ENGINE FIRE DETECTION SYSTEM FAILED TO TEST. TROUBLESHOOTING DETERMINED THAT THE ZONE 2 FIRE LOOP WAS DEFECTIVE PN 3001-133-900-500-6. INSTALLED NEW FIRE LOOP IAW THE LMM CHAPTER 72-00-05 AND AMM 26-10-00 FUNCTIONAL CHECKS SATISFACTORY.