As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING START OF APU WITH BLEEDS ON, COCKPIT FILLED UP WITH THICK SMOKE. ISOLATED APU AND DETERMINED TO BE SOUCE OF SMOKE IN AIR CONDITIONING. REMOVED AND REPLACED APU, SERVICED AS REQUIRED AND OPS CHECKED. OPS AND LEAK CHECKED GOOD. ACCOMPLISHED IAW MM 49-10-00, 49-20-00 AND 12-11-03.