As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EPSU AT FIN 13WL OPS CHECK INOP - DURING HEAVY CHECK - RON MAINTENANCE, EPSU AT FIN 13WL FAILED OPS CHECK. NO FLIGHT EFFECTED, NO GROUNDING. REMOVED AND REPLACED EPSU AT FIN 13WL AND ALL OPS CHECK OK IAW AMM 33-51-38 PB 401. NO FURTHER MX REQUIRED.