As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FA REPORTS EMERGENCY LIGHTS TURNING ON AND OFF IN THE CABIN. PERFORMED OPS CHKD EMERGENCY POWER SUPPLY UNITS BITE PER TSM 33-51-00-710-001-A. TEST FAULTS EPSU 13WL AFT L CLASS 1. 984478. REPLACED EPSU 13WL REF A321 AMM 33-51.SYS TEST NML. (LP 6871642)