What was found
ELEC GEN SYS L1 ADVISORY LEFT 1 GENERATOR CHANNEL INOPERATIVE. FIM TASK REF : 24-20-F0-M4A-421A-A CMC MSG# 2418431 LEFT 1 GENERATOR CONTRO L UNIT CMC MSG# 2418431. LEFT 1 GENERATOR CONTROL UNIT CMC MSG# 2418431. FOLLOWED BY LOSS OF L1 ENG GEN, CREW TRIED RESET OF ULTIPLE STATUS MESSAGES. L1 GEN WITH NO HELP. THIS WAS FOLLOWED BY LOSS OF L AC BUS AND M CREW DEBRIEF: CREW NOTICED LOSE OF PACK AIR FLOW WITH L1 CAC STA REF RELATED FAULTS 24-18121, 24-18431, 24-18531 BOEING RECOMMEND REPLACE L1 GEN. DMC-B787-A-24-21-09-00B-520A-A. REMOVED VARIABLE FREQUENCY STARTER GENERATOR REF INSTALLED L1VARIABLE FREQUENCY STARTER GENERATOR #1ENGINE PER DMC -B787-A-24-21-09-00B-720A-A OPS NORMAL