As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 403, NR 1 ENGINE FIRE WARNING FLASHED A COUPLE OF TIMES DURING FINAL APPROACH LOOP A HANDLE AND MASTER LIGHTS. DEFERRED PER MEL 26-2-3 A-LOOP DMI NR 31485 PLACARD INSTALLED CAT C B-LOOP. OPS CK GOOD SP C/W 26-2. T/S SYS IAW MMS 26-10-0. REMOVED AND REPLACED 1 DETECTOR NR 1 ENG IAW MMS 26-10-1. RAN NR 1 ENG PER JRH. SYS TESTS GOOD. THIS ACTION CLEARS MDDR NR 31485 PLACARDS REMOVED AIRCRAFT WAS GROUNDED.