What was found
WITH BOTH ENGINES RUNNING AND CLEARED FOR PUSHBACK, THE DC BUSS ILLUMINATED, THE FMS WENT BLANK FOLLOWED BY A MAIN BATTERY HOT WARNING. THE MAIN BATTERY HOT CHECKLIST WAS RUN AND THE AIRCRAFT ENGINES WERE SHUTDOWN WHEN SMOKE WAS OBSERVED COMING FROM THE NR 2 ENGINE NACELLE BY THE RAMP CREW. MAINTENANCE INSPECTED THE AIRCRAFT AND REPLACED THE NR 2 STARTER GENERATOR, THE NR 2 GCU, MAIN BATTERY, STARTER GENERATOR CABLES ALONG WITH RELAYS 2431-K2, 8011-K4, 8011-K3, AND 8011-K5. OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.