As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: WHILE PERFORMING EPSU SYSTEM TEST FOR CIDS 1, RECEIVED CLASS 1 FAULT FOR BATTERY/EPSU (10WL) FORWARD LEFT. MAINTENANCE REPLACED THE EPSU BATTERY AT 10WL IAW AMM 33-51-38. PERFORMED EPSU BITE IAW AMM 33-51-00-710-001-A, TEST GOOD.