As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY PWR SUPPLY UNIT FAIL BITE TEST. PTP SHOW MESSAGE EPSU INT LOAD FWD L REMOVED AND REPLACED EPSU BATTERY REF AMM TASK 33-51-38-000-002-A AND TASK 33-51-38-400-002-A. OP CHECK ESPU BITE CHECK GOOD REF AMM TASK 33-51-00-710-001-A.