As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: WHILE ACCOMPLISHING PS CHECK FOUND CLASS 1 FAULT ON EMERGENCY POWER SUPPLY UNIT SYSTEM TEST FOR EMERGENCY POWER SUPPLY UNIT FIN 14WL. ACCOMPLISHED TASKS PER FIM 33-51-00. RESET CONNECTORS ON 14WL ACCOMPLISHED OPERATIONS TESTS PER AMM 33-51-00.