Canon PC980 Service Manual - Page 311

CHAPTER 11 TROUBLESHOOTING 4. Adjusting the Reproduction Ratio (fine adjustment) Adjust the reproduction ratio if you have replaced the following: • DC controller PCB Making Adjustments Before Starting the Work • Meter 1) Before replacing the DC controller PCB, turn on the power; then, connect the meter probes to CP23 and GND on the DC controller PCB, and measure the voltage. + probe ........CP23 - probe .........GND VR106 CP23 GND VR104 VR105 VR106 VR107 CP23 CPGND1 Figure 11-270 2) After replacing the DC controller PCB, measure the voltage as in step 1); then, turn VR106 on the DC controller PCB so that the reading is the same as before replacement. 11-46 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)