What was found
(CAN) THE FLIGHT CREW REPORTED A NR 2 DC GENERATOR FAULT SHORTLY AFTER START ACCOMPANIED WITH SMOKE COMING FROM THE NR 2 DC GENERATOR EXHAUST VENT ON THE NACELLE.THEY ALSO AREPORTED THAT THE DC BUS CAUTION LIGHT WAS ILLUMINATED AND THE MAIN BATTERY TEMP WAS HIGH. THE NR 2 ENGINE WAS SHUT DOWN.THE NR 2 START/GEN, NR 2 DC GCU, DC START CONTACT RELAY (2431-K2). MAIN BATTERY AND START/GEN LEADS TO THE FIREWALL WERE ALL REPLACED.