As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: FAULT MESSAGE FOR EMERGENCY POWER SUPPLY UNIT 13WL DISPLAYED DURING SYSTEM TEST. MAINTENANCE ISOLATED THE SOURCE OF THE FAULT TO THE R4 DOOR SLIDE RAFT ASSEMBLY AND REPLACED IT PER JOB CARD 26L00025011. A SATISFACTORY OPERATIONAL CHECK OF THE EMERGENCY LIGHTING SYSTEM WAS ACCOMPLISHED WITH NO FAULTS NOTED.