As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L PACK OFF EICAS MESSAGE PACK OFF LIGHT. PERFORMED LT PACK BITE THEN NO FAULT FOUND. L FCV WIRING CHECK OK, IAW FIM 21-51 FAULT TREE 852. REMOVED AND REPLACED L-PACK FLOW CONTROL VALVE AND L-PACK OPERATIONS NORMAL, PER AMM 21-51-01 ALSO L PACK OPERATION CHECK OK WITH BOTH ENGINE RUN.