As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HAZY SMOKE IN CABIN WITH APU BLEED ON, STARTED TO DISSIPATE WITH BLEED SELECTED OFF. INSPECTED APU COMPARTMENT FOR EVIDENCE OF FIRE OR SMOKE DAMAGE. NONE FOUND. RAN APU WITH BLEEDS SELECTED ON FOR APPROX 10 MINUTES. NO DEFECTS NOTED. ACFT OK FOR SERVICE.