What was found
HEAVY SMOKE ODOR IN THE FLIGHT DECK ONLY, IMMEDIATELY FOLLOWED BY LOSS OF LEFT GEN AND BOTH UTILITY BUSES. FIRE DEPT REPORTED SEEING SMOKE COMING OUT OF E&E COMPT. NO EICAS MESSAGES REPORTED. APU STARTED AND DID NOT PICK LEFT BUS. SUSPECT A SHORT IN E&E. FOUND NR 1 ENG GCU BURNT. REMOVED AND REPLACED GCU AND IDG AND BPCU REF AMM 24-11-01 24-41-03 24-22-02. ALL OPS CHECK GOOD. IDG LEAK CHECK GOOD AND PERFORMED SMOKE OR ODOR IN THE FLIGHT DECK AND OR CABIN CONDITIONAL INSPECTIONS.