As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED - DURING FUNCTIONAL TEST FAULT WARNING FOR THE L1 DOOR, EPSU (EMERGENCY POWER SUPPLY UNIT) 10WL, / DEU B (DECODER/ENCODER UNIT) 300RH1 DISPLAYED. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT (SEE AALA202006089012) AND SECURED ELECTRICAL CONNECTOR ON DEU B (DECODER/ENCODER UNIT) 300RH1 WHICH WAS FOUND TO BE UNSECURE (SEE AALA202006089013). A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED PER AMM TASK 33-51-00-710-001-A.