What was found
BOS - FLT 749 EN ROUTE MAD TO CLT. F/A REPORTED SMOKE/FUMES IN CABIN. DIVERTED TO BOS. AFTER TURNING OFF UTILITY/BUSES, CABIN STARTED CLEARING. ACCOMPLISHED CABIN AIR QUALITY CHECK. CHECKED C/B CKPT + EEBAY, RECIRC FANS GALLEYS AND LAVS AND DID VISUAL SEAT POSITIONS. RAN APU AND AIR CONDITIONING SYSTEMS, ALL CHECK NORMAL. REPLACED LIGHT BALLASTS AT SEATS 17/18. REPLACED HEPA FILTERS. RAN ENGS OK. NO SMELL OR SMOKE NOTED.