As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#20, LHR-JFK. (ETOPS) 'ENG 1 LOOP A FAULT ON ECAM ( ENGINE FIRE DETECTION SYSTEMS 1) LOOP A ); REMOVED AND REPLACED ENG #1 FIRE DETECTION UNIT (FDU) PER AMM 26-12-34. OPS TEST OK. NO FAULTS OR DEFECTS NOTED. MX-4 UPDATED. PLACARD REMOVED. MDDR CLEARED.'