As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU NO START AT DEPT TIME. NO FAULTS ON ECU R/R ECU NO HELP. REMOVED AND REPLACED BATTERY NO HELP. APU HANGS UP AT 11 PERCENT WITH SMOKE AND FLAME FROM TAIL PIPE. CHIP DETECTORS HAVE NO METAL R/R EXCITOR BOX NO HELP. REMOVED AND REPLACED APU RAN APU AND LEAK CK, NO DEFECTS NOTED. APU OPS NORMAL IAW MM.