As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/A REPORTED SMOKE IN CABIN WHEN ACFT PARKED AT THE GATE. INSPECTED ACFT FOUND NO DEFECTS WITH EXTERNAL DC POWER APPLIED TO ACFT. STARTED APU, BLEEDS OIL MIST AND SMOKE FILLED THE CABIN AND SELECTED APU OFF. GROUND RAN WITH ENGINE BLEEDS SELECTED INDIVIDUALLY, NO OIL OR SMOKE VISIBLE. R&R THE APU.