As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN TO FIELD DUE TO SMOKE IN THE FLIGHT DECK. FOUND A LEAKAGE ON THE BLEED DUCT CLAMP OF THE NR 1 ENGINE INBOARD REVERSER HOLD OPEN ACTUATOR. THE ACTUATOR WAS REPLACED. A PACK BURN-OUT PROCEDURE VERIFIED PROPER FUNCTIONING OF ACTUATOR.