As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PRE-FLIGHT THE CREW REPORTED THAT THE FIRST AND THIRD EMERGENCY LIGHTS WERE NOT ILLUMINATING DURING TESTING. GROUND MX CREW OPERATIONALLY CHECKED THE EMERGENCY LIGHTS AND OBSERVED THAT ALL EMERGENCY LIGHTS WERE OPERATING NORMALLY AND NONE APPEARED TO BE NON OPERATIONAL. THE GROUND MX CREW WAS UNABLE TO DUPLICATE THE ISSUE REPORTED. THE ACFT WAS RETURNED TO SERVICE.