As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING INSPECTION, AN EMERGENCY LIGHT DID NOT ILLUMINATE DURING THE PRESS TO TEST CHECK. ON TROUBLESHOOTING IT WAS DETERMINED THE FAILURE WAS DUE TO A WEAK BATTERY. REMOVED AND REPLACED THE BATTERY PACK IAW AMM 25-65-17 AND OPS CHECKED GOOD. NO FURTHER ISSUES.