As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#1620, BOS-LHR. (ETOPS) ENG 1 FIRE LOOP A ECAM AT CRUISE ( ENGINE FIRE DETECTION SYSTEMS 1) LOOP A ); REMOVED AND REPLACED ENG 1 PYLON FIRE-DETECTOR LOOP A IAW AMM 26-12-16. OPS CHECK SATISFACTORY AT THIS TIME. THIS CLEARS MDDR 523812. MX-4 UPDATED. PLACARD REMOVED.