As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ESCAPE SLIDE LIGHT / EMERGENCY POWER SUPPLY UNIT 10WL FORWARD LEFT FAULT MESSAGE DISPALYED DURING FUNCTIONAL TEST. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 10WL AND ACCOMPLISHED A SATISFACTORY OPERATIONAL / BITE CHECK PER AMM 33-51-38 AND AMM 33-51-00.