As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 3322 DURING AIRFRAME 2A / ESPU SYSTEM TEST GOT FAULT EPSU (18WL) DOOR 4R. CORRECTIVE ACTION: PERFORMED BITE TEST ON EPSU RECEIVED "UNIT FAULT" MSG SLAVED IN NEW EPSU WITH BAT. NO GOOD SWAPPED BACK. INSTALLED NEW EPSU 18WL AT AFT LEFT DOOR. (4863049)