As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. DURING EMERGENCY EXIT LIGHTING TEST, FAULT WAS GENERATED. BATTERY AND EMERGENCY POWER SUPPLY UNIT (10WL) FORWARD LEFT TEST DID NOT PASS PER STEP 16 OF PERIODIC SERVICE CHECK. REPLACED EMERGENCY POWER SUPPLY UNIT (10WL) AND BATTERY PER MM 33-51-38. OPERATIONS CHECK NORMAL. THIS SDR IS FOR THE BATTERY PACK. (SEE CONTROL #AALA201810159026)