As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3450 THE CREW REPORTED THE CABIN AND CABIN EMERGENCY LIGHTS ON ICU PANEL WOULD NOT GO OUT. UNABLE TO COMMUNICATE WITH FLIGHT ATTENDANT. THE AIRCRAFT WAS REMOVED FROM SERVICE. RESET INTERPHONE CONTROL UNIT FOR FORWARD FLIGHT ATTENDANT AND OPS CHECK GOOD IAW EMB AMM 23-31-02. THE AIRCRAFT WAS RETURNED TO SERVICE.