As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU WOULD NOT START. REACHED 17% AND WOULD SHUT DOWN.(<P>PERFORMED APU BITE PROCEDURE IAW FIM 49-11-00. FOUND FAULT "AC START CIRCUIT". FOLLOWED TS FIM TO BOX 23. REMOVED AND REPLACED RELAY K197 PER WDM 49-41-11. OPS CHECKED GOOD. APU OPERATIONAL.</P>)