What was found
CREW REPORTED SMOKE IN THE CABIN. THE AIRCRAFT DIVERTED AND LANDED WITHOUT INCIDENT. MAINTENANCE PERFORMED ENGINE, APU, AND PACK CHECKS WITH NO DEFECTS NOTED, CABIN INSPECTION REVEALED INOPERATIVE SIDEWALL LIGHTS AT SEATS 5A & 20A. MAINTENANCE DISCONNECTED THE AFFECTED BALLASTS. REMOVED AND REPLACED THE BALLASTS, OPS TESTED WITH NO DEFECTS NOTED. APPROVED FOR RETURN TO SERVICE.