As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DURING REPLACEMENT OF L4 DOOR ESCAPE SLIDE FOUND EMERGENCY POWER SUPPLY UNIT FAULTED AT AFT LEFT EMERGENCY EXIT. REPLACED EMERGENCY POWER SUPPLY AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 33-51-38.