As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#2104, BOS-LGW. (ETOPS) INTERMITTENT ENG 2 FIRE LOOP A FAULT ( ENGINE FIRE DETECTION SYSTEMS 1) LOOP A ). REMOVED AND REPLACED ENG 2 CORE AGB LOOP A FIRE/OVERHEAT DETECTOR (4002WD1) IAW AMM 26-12-17 OPS CHECK GOOD NO FAULT PRESENT MDDR REMAINS OPEN TO MONITOR DURING NEXT LEGS) THIS CLEARS THIS MDDR MX-4 UPDATED PLACARD REMOVED MCC NOTIFIED.