As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING PS1 FOUND THE LEFT OVERWING EXIT EMERGENCY SIGN NOT ILLUMINATED DURING TEST (INTERIOR}. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE NR 4 POWER INVERTER IAW EMB MM 33-50-11. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.