COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)3. Main Relay PCBFigure 10-5094. Sub Relay PCBFigure 10-510CHAPTER 10 TROUBLESHOOTING10-81NameRight cover switchDrum cartridge detecting switchSW No.SW641SW6422 1J644 4 J642 1 J6436 1 5 1J648J64531J64116SW64141J647SW642J646B11A1B1A11J67121J673611J6764SW671SW673 J674J6756121NameDelivery cover/front cover switchTurret button switchSW No.SW671SW672Download free service manual at http://printer1.blogspot.com