As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT GATE APU FIRE HANDLE LIGHT ON AND BELL, PULLED HANDLE AND DISCHARGED BOTTLE. INSPECTED THE APU COMPARTMENT AND NO EVIDENCE OF FIRE DAMAGE OR OVERHEAT CONDITION WERE NOTED. RESET APU FIRE HANDLE AND ACCOMPLISHED APU FIRE TEST. SYSTEM TESTED NORMAL. REPLACED APU FIRE EXTINGUISHER BOTTLE.