Canon PC300 Service Manual page 75

ES OPERATIONS AND TIMING 23%
5) Short the three jumper wires (JP604,
JP605, JP607) on the control panel PCB
at the same time using a screwdriver.
Caution: es
'Take adequate care not to short wires
_other than those specified.
JP607
JP605
JP604
Figure 3-44
6) While keeping the condition in step 5),
switch the copier ON.
* '0' is displayed, the scanning lamp
goes ON, and the main motor starts to
rotate.
7) Stop shorting the jumper wires.
8) Set the digital multimeter to the 20V DC
range, and turn VR602 (AE offset adjust-
ment) until the voltage between the
anode side of the diode (D606; +) and
JP607 (GND) is 4.0 +0.1 V.
3-48 COPYRIGHT © 1994 1995 CANON INC.
Note: :
You must use a Digital Multimeter when
making adjustments in steps 8) and: 10).
JP607
VR602 VR603
D606 (anode side) Control panel PCB
Figure 3-45
9) Place about five sheets of blank copy
paper.
10) Turn VR603 (AE gain adjustment) until
the voltage between the anode side of
the diode (D606; +) and JP607 (GND) is
1.8 +0.1 V; see Figure 3-45.
11) Switch the copier OFF.
Note:
Make sure that the jumping wires are no
longer shorted.
12) Switch the copier ON once again.
13) Set the density correction switch
(SW606) to the center (of the three set-
tings).
14) Make sure that the AE indicator is ON.
15) Set the newspaper used in step 4) on
the copyboard once again; this time,
move the newspaper to a different area.
16) Make a copy, and make sure that it is
not foggy and has adequate text density.
* If foggy,
Turn VR602 clockwise slightly.
* If text density is low,
Turn VR602 counterclockwise slightly.
17) Repeat steps 15) and 16) until the densi-
ty is optimum.
CANON PC300/320/325, F0210290 REV.1 FEB. 1995 PRINTED IN JAPAN (IMPRIME AU JAPOK)