As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: EMERGENCY LIGHTS TEST SHOWS FAULT EMERGENCY POWER SUPPLY UNIT COMMUNICATION AFT LEFT - MAINTENANCE CHECKED EMERGENCY POWER SUPPLY UNIT CONNECTION AND RECONNECTED PER TSM 33-51-00-810 WHICH RESLUTED IN THE FAULT BEING CLEARED