As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMOKE IN CABIN WHEN APU BLEED SELECTED IN BHM. MAINTENANCE TROUBLESHOT, REMOVED AND REPLACED THE APU ASSEMBLY PER THE AIRCRAFT MAINTENANCE MANUAL. CHECKS WERE MADE PER THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.