As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU AUTO SHUTDOWN OCCURED DURING START ATTEMPT - GROUND SERVICES ADVISED A LARGE AMOUNT OF SMOKE WAS SEEN FROM APU TAIL PIPE DURING THE START ATTEMPT. PLACED APU ON MEL 49-00-1. REPLACED APU IGNITOR PLUGS IAW MM TASK 49-40-04-000-801 AND 400-801. OPS CHECKED NORMAL IAW MM TASK 49-40-04-710-802 CLEARED DMI 549328 C/W H/S NR 49-0008 NO DEFECTS NOTED. RETURNED TO SERVICE.