As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: EMERGENCY LIGHT TEST FAILED FOLLOWING FAULTS INCLUDEEPSU INT LOAD AFT LEPSU EXT LOAD AFT LEPSU BATTERY EMEP REPSU BATTERY AFT L EPSU UNIT. MAINTENANCE REPLACED 10WL ESPU AND BATTERY IAW AMM 33-51-38, OPS CHECK GOOD.