As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL FLT 742 ENROUTE PHL TO BCN. ABOUT 1 HOUR INTO FLIGHT, RECEIVED L INOP AND PACK OFF LIGHTS, WITH L PACK TEMP DISPLAYED ON EICAS. THE CONDITION DID NOT RESET WHEN STAND BY WAS SELECTED AND RESET WAS PUSHED. SINCE THE FLIGHT COULD NOT CONTINUE INTO ETOPS OPERATION, IT RETURNED TO FIELD PHL AND LANDED WITHOUT FURTHER INCIDENT. MX REPLACED THE LT PACK RAM AIR EXHAUST DOOR ACTUATOR. OPS CHECKS OK.