As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: MULTIPLE FAULTS FOR EMERGENCY POWER SUPPLY UNIT 10WL DISPLAYED DURING SYSTEM TEST. MAINTENANCE REPLACED 10WL AND 15WL EMERGENCY POWER SUPPLY UNITS, THE EMERGENCY POWER SUPPLY BATTERY FOR 10WL, THE L1 DOOR SLIDE AND THE L2 DOOR SLIDE WHICH CLEARED ALL FAULTS.