Making Checks On The Reader Unit - Canon imageRUNNER 5065 series Service Manual

Chapter 14

14.1.4 Making Checks on the Reader Unit

iR5065 / iR 5055 / iR5075 / / /
14-4
<Checking the Solid Black
B Generate a solid black print.
Is the density
too low or too high (too
light or too dark)?
YES
Check the following readings (VD target value) in service mode:
COPIER>DISPLAY>DPOT>VDM (for copier image)
COPIER>DISPLAY>DPOT>VDM-P (for printer image)
Are the
readings ± 6 V of the
target value?
(*1)
YES
Check the following readings (VL1 target value) in service mode:
COPIER>DISPLAY>DPOT>VL1M (for copier image)
COPIER>DISPLAY>DPOT>VL1M-P (for printer image)
Are the
readings ± 6 V of the
target value?
(*2)
YES
Adjust the offset of the VD target potential.
<Checking the Halftone Density>
C
Generate a halftone image.
Is the halftone
density optimum?
Adjusting the Offset Value of the VD Target Potential
(VD-OFFSET/VD-OFFSET-P)
COPIER>ADJUST>V-CONT>VD-OFST (for copier image)
COPIER>ADJUST>V-CONT>VD-VD-OFST-P (for printer image)
-5 -4
Density>
NO
Check the primary charging
NO
system; if normal, replace the
photosensitive drum.
Check the following, and replace them if
necessary:
NO
1. Laser (for output)
2. Potential control system
3. Photosensitive drum
F-14-4
YES
End.
To check a copier image,
NO
See if No. 6 and No. 7 (halftone) of the Test Chart is
reproduced to the more or less the same density.
To check a printer (PDL) image,
See if the density of the halftone area represents the
original data properly.
D
Lighter image Darker image
Default
-3 -2 -1 0 +1 +2
F-14-5
C
D
+3 +4 +5
0015-5283