What was found
FLIGHT 6380, STL TO CVG - AFTER LEVELING OFF AT FL230, THE FLIGHT CREW NOTICED AN ELECTRICAL BURNING ODOR IN THE FLIGHT DECK. THE AIRCRAFT DIVERTED TO IND AND LANDED WITHOUT INCIDENT. DURING ENGINE RUNS, MAINTENANCE WAS ABLE TO DUPLICATE THE SMELL AND INSPECTED THE RECIRCULATION FANS AND DUCTING FOR DEFECTS BUT FOUND NONE. THE NR 2 PACK WAS THEN IDENTIFIED AS PRODUCING THE ODOR WHILE RUNNING. AFTER INSPECTING THE NR 2 PACK, THE ATTENUATOR DUCT NEAR THE FORWARD RECIRCULATION FAN WAS FOUND BLOWN AND APPEARED TO HAVE MELTED. THE DUCT WAS REPLACED AND THERE WAS NO FURTHER SMELL NOTED.