As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: INOP EMERGENCY POWER SUPPLY UNIT (EPSU) EMERGENCY RH SIDE. REPLACED EMERGENCY POWER SUPPLY UNIT (EPSU) FIN: 12WL IAW AMM33-51-38-000-001-A AND AMM 33-51-38-400-001-A.REFER TO INDIVIDUAL SIGN OFFENTRIES FOR WORK STEPS PERFORMED. ATTACHED FORM ME-0470.