As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE IN COCKPIT / CABIN: AFTER STARTING APU AND TURNING ON BLEED AIR THE APU DID NOT HAVE THE NORMAL SOUND TO IT I LOOKED OUTSIDE AND THE PERSONNEL WAS LOOKING AT THE BACK OF THE PLANE AND SHORTLY AFTER THE COCKPIT AND CABIN FILLED WITH SMOKE AND THE APU AUTO SHUT DOWN. R/R OPS CHECK GOOD IAW CESSNA 680 MM 49-10-00.