What was found
CIDS 1 EPSU SYS TEST SHOWS "EPSU (12WL) EXT R" MESSAGE. TEST OF THE EPSU SHOWS "UNIT FAILED" FAULT. R & R THE EPSU BATTERIES TWICE. NO GOOD. INSPECTED FOR BURNT OUT LIGHTS. ALL EMERGENCY LIGHTS OPERATIONAL. RESEATED CONNECTOR PLUG. NO GOOD. NO ECAM MESSAGE. ENTIRE EPSU UNIT NEEDS REPLACEMENT. PANEL FOR UNIT REMAINS OPEN FOR MAINTENANCE. REMOVED AND REPLACED EPSU FIN 12WL IAW AMM 33-51-38-400-001-A. ALL BITE AND LEARN IN PROGRAMMING OPS CK NORMAL. PERF CIDS INTERFACE AND POWER UP TEST REF AMM 23-73-00-740-005-B. TEST OK. OK TO CONTINUE. REF LP 8095930 FOR BORROWED PART TRANSACTION AND CARRY.