SM(SBW) reported (While he was doing platform duty), that rear DT & Rear M1 car external light was n ot illuminated when train doors were opened ~~~~~ SM(SBW) reported (While he was doing platform duty), that rear DT & Rear M1 1559 car external light was not illuminated when train doors were opened Both location Still O/S 24/04/20--01/07/20 S(D) 3wckly check - 1559 -exterior light -OK.Working in door opened condition .23/11/20 (U8-D) . 3559 -exterior light still O/S .23/11/20 (U8-D) 3WC1 Checked -OK 25/01/21 R5(D)