As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FINAL APPROACH TO ATL RECEIVED LDC CLS 1 A/F Y/D1 MSG AND THEN NOTICED FUMES IN FLIGHT DECK. FUMES BECAME WORSE AFTER A FEW MINUTES AND COULD BE DETECTED THROUGHOUT THE CABIN, LANDING WAS UNEVENTFUL. REPLACED FAC (FLIGHT AUGMENTATION COMPUTER) AND THE YAW DAMPER SERVO ACTUATOR AND TESTS OK.