As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY POWER TEST INITIATES NORMALLY, AFTER 30SEC TEST APPEARS TO COMPLETE NORMALLY BUT EMERGENCY POWER TST FAIL ALERT APPEARS. DUE TO OTHER FAULTS NOTED ON ENG RUN ORDERED THE EPCU UNDER THE TSI. R & R EPCU OPS CHECK NORMAL. EMERGENCY POWER TEST ALSO CHECKS NORMAL MM 24-08-01-4.