What was found
FLIGHT ATTENDANT PERSONNEL REPORTED SMOKE IN THE CABIN. THE AIRCRAFT RETURNED TO THE ORIGINAL POINT OF DEPARTURE (RFD). MAINTENANCE PERSONNEL WERE DISPATCHED AND FOUND THE COALESCER BAGS EXCESSIVELY DIRTY. REPLACED THE RIGHT AND LEFT AIR CONDITIONING PACK COALESCER BAGS IAW AMM 21-20-02. RETURN TO SERVICE OPERATIONAL CHECK WAS PERFORMED AND ALL SYSTEMS OPS CHECK NORMAL. THE AIRCRAFT WAS RETURNED TO SERVICE.