As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK, NR 1 N1 & EGT GAUGE FAILURE THEN INTERMITTENT OPERATION ENG 1 FAILURE ECAM AND ENG #1 REVERSE UNLOCK ECAM. FMC REVERTED TO ENGINE OUT MODE. REPLACED #1 ENGINE LEFT FAN CASE HARNESS 21W4118 PER AMM 71-51-01/401 DUE TO D4998P LOCKING MECHANISM FAILURE. ACCOMPLISHED ENGINE TEST #6 AND OPERATED THRUST REVERSER, NO FAULTS NOTED.