As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 160, DURING START OF DESCENT, NR 1 ENG FIRE WARNING LIGHT ILLUMINATED AND WARNING BELL ACTIVATED INTERMITTENTLY FOR 5 SECS IN DESENT "A LOOP' PER MEL 26-2-3 CAT C MDDR NR 31535 PLACARD INSTALLED, S/P COMPLIED WITH M/M 26-10-0. R7R FIRE DETECTOR CONTROL BOX UNIT IAW 26-10-4 TESTING SYSTEM OK DMI 31535 CLEARED. AIRCRAFT WAS GROUNDED.