As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU SHUT DOWN AT GATE TWICE. BIT APU CONTROL BOX, GEN FILTER ILLUMINATED. CHECKED DIFF PRESS SW & FILTER, NO DEFECTS NOTED. R & R GEN CHIP DETECTORS, NO METAL FOUND. FOUND GEN DIFF SW CONNECTOR BACK SHELL CONNECTOR BROKEN & SAFETY WIRE BROKEN. CHECKED ABOVE DETECTORS IAW AMM 49-27-04 & PRESS SW & FILTER IAW AMM 49-27-03.