As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD LEFT EPSU FAILS OPERATIONAL TEST OF EMERGENCY LIGHT SYSTEM. REMOVED AND REPLACED FORWARD LEFT EMERGENCY POWER SUPPLY UNIT (EPSU) (10WL) PER MAINTENANCE MANUAL 33-51-38. OPERATIONAL CHECK WAS GOOD. ***SUPPLEMENTAL*** WILL RESUBMIT WHEN COMPONENT SERIAL NUMBER, TIME, & CYCLE BECOMES AVAILABLE.