As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: CABIN INTERCOMMUNICATION DATA SYSTEM 1 IS PROVIDING NO DATA TO CENTRAL FAULT DISPLAY INTERFACE UNIT DETECTED BY GROUND SCAN OF CENTRAL FAULT DISPLAY INTERFACE UNIT. REMOVED AND REPLACED SLIDE WITH SERVICEABLE SLIDE PER AMM 25-62-44.