TC reported train doors was not proven closed. TC opened and closed train doors an d operated ADBS, to no avail. DIRBS was operated, pax disenbarked at KRJ2. ~~~~~ #663/664 DIR illuminated without DBI indication. Found #2664 B3 door physically closed but door sensing s/w not fully engaged. Measured gap between door sensing s/w and door actuating bracket, 16.7mm (optimal criteria is 14.5mm-15.5mm). Adjusted actuating bracket to optimal criteria, 14.5mm to 15.5mm from door sensing s/w, ok. Door cyclic test ok. Additionally checked all saloon doors mating strip distance measurement (63mm-64.5mm criteria). Adjusted doors that failed the criteria. Carried out door cyclic test-ok. Found #3663-A1 door isolation cock damaged. Replaced and function check ok. Not: 2136969 raised to RSW. Done by Kumar/Jack/Koh. 02/03/20.