As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAILED AT GATE. APU INOPERATIVE. APU FAILED AT PUSHBACK. ACP BITE OF ECU FOUND INLET DOOR FAULT. ACP VISUAL AND AUDIBLE CK OF ACTUATOR AND CHECKED SECURITY OF DOOR OPEN SWITCH. STARTED APU SEVERAL TIMES AND LOADED APU. OPERATION NORMAL IAW AMM.