As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE INDICATION ON EICAS AT GATE. CREW DISCHARGED APU FIRE EXTINGUISHER. MX PERFORMED APU FIRE WARNING INSPECTION AND FOUND FIRE TO BE LIMITED TO APU STARTER GENERATOR AND ASSOCIATED DUCTING AND OUTLET SCOOP. APU PLACED ON MEL. ACFT APPROVED FOR RETURN TO SERVICE.