As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ENGINE SHUTDOWN ON AC 508, WITH APU OPERATING, PAX , F/A'S REPORTED SMOKE IN CABIN. SHUTDOWN ENGINE. MAINTENANCE REMOVED AND REPLACED DAMAGED OIL COOLER INTAKE DUCT P/N OFF 4501709, P/N ON 4504473 REF NR 409 116560. FOUND APU OIL OVER-SERVICED BY 1 QUART, BROUGHT OIL TO PROPER LEVEL. OPS AND CABIN SMELL CHECKS GOOD AT THIS TIME. REMOVED FROM DMR-MXC NOTIFIED.