As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU START WAS ABORTED DUE TO A HUNG START. UPON INSPECTION, FOUND SMOKE AND FIRED EXTINGUISHER BOTTLE. INSPECTED APU AREA, NO OBVIOUS DEFECTS NOTED. REMOVED AND REPLACED APU FIRE BOTTLE AS PER EMB MM 26-21-00. REMOVED AND REPLACED MAIN BATTERY IAW MM 24-32-01.