COPYRIGHT © 2000 CANON INC. 2000 2000 2000 2000 CANON iR5000/iR6000 REV.0 JULY 2000CHAPTER 3 STANDARDS AND ADJUSTMENTS3-30 T8.3 Zero Level CheckA "zero level check" is a check made to find out whether the control system of the DCcontroller PCB identifies 0 V when the drum surface potential is 0 V.A zero level check may be made in either of two ways, so as to find out whether a circuiton the the DC controller PCB or the potential measurement circuit is normal:1) Method 1: for checking the level shift circuit of the DC controller PCB2) Method 2: for checking the potential measurement circuit8.3.1 Method 11) Turn off the main power switch.2) Remove the rear upper cover.3) Short CP106 [1] and CP105 [2] on the DC controller PCB using a cable whose bothends are equipped with an alligator clip or a probe.When shorting CP106 and CP105, be sure to keep the shorting tool awayfrom other elements or the pattern on the PCB.F03-803-01J110J113J111J125J109 J107 J112 J104 J105 J115 J102J101 J119 J106J118J103 J124 J108J114J302J120J116J117J121 J123J126J303J203J100 J201CP104CP103CP101CP105CP106CP111CP110CP108CP109CP107[2][1]
