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) 'ENGINE 2 FIRE LOOP A FAULT ( ENGINE FIRE DETECTION SYSTEMS 1) LOOP A ); REMOVED AND REPLACED FDU #2 AS PER AMM 26-12-34 AND PER UPPER LEADERSHIP. OP'S CHECK IS GOOD. MX-4 UPDATED. PLACARD REMOVED. MDDR CLEARED.'