As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX - EEL - DURING OVERNIGHT MAINTENANCE DISCOVERED THE EMERGENCY EXIT LIGHTS FAILED OPERATIONAL TEST, MESSAGE "COMM AFT L". MAINTENANCE REMOVED AND REPLACED POWER SUPPLY UNIT, 13WL, IAW AIRBUS 320 AMM 33-51-38. OPERATIONAL CHECKS WERE GOOD.