As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOR FLIGHT 3520 MAINTENANCE REPORTED SMOKE IN THE COCKPIT WITH PACK NR 1 RUNNING ON THE APU. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED NR 1 PACK (AIR CYCLE MACHINE) IAW AMM 21-51-03. THE AIRCRAFT WAS RETURNED TO SERVICE.