As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: DONT PASS EPSU TEST 10WL PN:3214-54-10 SN:006421 IN FWD GALLEY AREA. PERFORMED TROUBLE SHOOTING IAW TSM 33-51-00-810-801-A STEP 1 THRU 4.B.(1). MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT FIN 10WL IAW AMM33-51-38-000-001-A, AMM 33-51-38-000-002-A, AMM 33-51-38-400-001.