As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH PACKS SELECTED OFF AND APU BLEED AIR SELECTED ON, STARTED THE RT ENGINE. NOTICED SMOKE COMING OUT OF FORWARD AIR CONDITIONING VENTS IN COCKPIT. STARTED THE LT ENGINE AND SMOKE BEGAN BILLOWING OUT OF COCKPIT FORWARD AND SIDE CONSOLE AIR CONDITIONING VENTS. SHUTDOWN ENGINES, APU AND AIRCRAFT POWER. MAINTENANCE BORESCOPED THE APU AND ENGINES AND FOUND THE NR 2 ENGINE, NR 1 AND 3 CARBON SEALS LEAKING. REPLACED THE NR 1 AND 3 CARBON SEALS. GROUND RUNS WERE GOOD.