As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING HORN, IN NOSE GEAR WELL, IS INOPERATIVE. TRANSFERRED TO DMI 12489 PER MEL 26-11-2 CAT-C. REF DMI 12489 APU FIRE WARNING HORN IN NOSE GEAR WELL IS INOPERATIVE. TROUBLESHOT PER WDM 49-41-0, FOUND HORN INOPERATIVE. REMOVED AND REPLACED HORN, OPS CHECKED NORMAL. THIS CLEARS DMI 12489.