As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING THE OPERATIONAL TEST OF EMERGENCY LIGHTS FOR PS CHECK TEST FAULTED ESCAPE SLIDE LIGHT ON CENTRAL FAULT DISPLAY SYSTEM, EMERGENCY POWER SUPPLY UNIT (13WL). REMOVED AND REPLACED L4 SLIDE AND RIGHT EMERGENCY LIGHT (12WL) BATTERY (AALA202106079003) PER AMM 33-51-38.