COPYRIGHT © 1998 CANON INC. CANON DADF-A1 REV.0 DEC. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON) 5-27CHAPTER 5 TROUBLESHOOTINGIV. VARIABLERESISTORS, LIGHT-EMITTING DIODES, ANDCHECK PINS BY PCBOf all variable resistors (VR), light-emitting diodes, and check pins, those neededwhen servicing the machine in the field arediscussed.Caution:Do not touch the variable resistors andcheck pins not discussed herein. They arefor the factory, and require special toolsand must be adjusted to high accuracy.A. DADF Controller PCBCaution:1. Some LEDs emit dim light even whenoff because of leakage current. This is anormal condition, and must be kept inmind:2. VRs that may be used in the fieldVRs that must not be used in the fieldSW1TP1J10J15J1CB1 J2 J14J12J11J7J6J13J5J9J8J3B12 B126 1113121312131142A1 A121 1 1 1 9101 4 228171DSW1SW2SW3LED1LED2Figure 5-401
