As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED APU INOPERATIVE TROUBLESHOT SYSTEM AND FOUND VOLTAGE AVAILABLE AT STARTER GEN. REMOVED STARTER GEN AND BRUSH COVER. FOUND 2 OUT OF 4 BUSHES WELDED IN BRUSH HOLDERS AND BUSH WIRES BROKEN OFF. INSULATION STRIP ON INSIDE OF BRUSH COVER WORN BURNED THROUGH. INSTALLED REPAIRED STARTER GEN OF SAME PN IAW GAC G200 MM., CH 49-40-05, OPERATIONAL CHECKS GOOD.