As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED (SHORT TERM STORAGE):: EMERGENCY POWER SUPPLY UNIT 15WL PRESS TO TEST BITE INOPERATIVE. BITE TEST SATISFACTORY FROM PTP PANEL. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT15WL PER AMM 33-51-38. BITE TEST SATISFACTORY IAW AMM 33-51-00.