As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VCT- DURING POST FLIGHT THE CREW NOTED THAT SMOKE WAS PRESENT IN THE COCKPIT WITH THE APU RUNNING. THE AIRCRAFT WAS RELEASED FOR FLIGHT. MAINTENANCE PERFORMED A OPERATIONAL CHECK OF THE APU AND AIR CONDITIONING SYSTEMS, COULD NOT DUPLICATE THE PROBLEM, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.