As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU DISCONNECTED ON ITS OWN. FOLLOWED BY BURNING SMELL IN CABIN COCKPIT PERFORMED INSPECTION PER AMM 05-51-26. NO DEFECTS NOTED. ALSO PERFORMED INSPECTION OF APU PER FIM 49-55 TASK 802. NO DEFECTES NOTED EITHER. RAN APU WITH BOTH PACKS. NO BURNING SMELL OR ODORS NOTED.