What was found
INFO TO MAINTENANCE: GOT ECAM: SMOKE LAVATORY DET FAULT. WITH THIS ECAM, ALSO LOST ENTIRE INTERPHONE SYSTEM TO INCLUDE FA PANEL AND ALL CALLS BUTTONS. APPLIED RESET PROCEDURE "SMOKE LAVATORY DETECTOR FAULT." AND RESTORED INTERPHONE AND CALLS AND FA PANEL. ECAM FOR SMOKE LAV DET FAULT REMAINED. TROUBLESHOT PER TSM 26-17-00-810-804A NO DEFECTS NOTED PERFORMED GND SCAN OF CIDS-SDF NO DEFECTS NOTED IAW AMM 26-10-00-740-802A. OK FOR SERVICE.