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 POWER SUPPLY UNIT TEST FAILED "ESCAPE SLIDE LT" 13WL, AND OTHER 13WL FAULTS. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT (AALA202105139016) AND BATTERY (AALA202105139021) 13WL PER AMM 33-51-38. REMOVED AND REPLACED DECODER ENCODER UNIT B (AALA202105139022) 300RH7 PER AMM 23-73-47. FAULT REMAINS, NO FIX. TROUBLE SHOOT TO R4 SLIDE. REMOVED AND REPLACED R4 SLIDE PER JOB CARD 26L00025010. EMERGENCY POWER SUPPLY UNIT TEST PASSED.