As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTS WOULD NOT TEST. MAINTENANCE INSPECTED AND CLEANED EMERGENCY LIGHT BATTERY PACK AT FSD AND RETURNED THE A/C TO SERVICE. UPON ARRIVAL AT ILN, MAINTENANCE REPLACED EMERGENCY LIGHT PACK AS A RELIABILITY PRECAUTION IAW DC9 MM 33-02-4.