As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: WHILE ACCOMPLISHING EMERGENCY LIGHTING SYSTEM OPERATIONAL CHECK PER TASK CARD 26L00005005, EMERGENCY POWER SUPPLY UNIT 10WL FAULT MESSAGE DISPLAYED. REPLACED EMERGENCY POWER SUPPLY UNIT 10WL AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.