Canon Image Reader-A1 iR5000i Service Manual page 597

3. Making Checks on the Printer Unit (2/2)
<Checking the Solid Black
A
Check the following readings in service mode:
COPIER>DISPLAY>DPOT>VDM (for copier image)
COPIER>DISPLAY>DPOT>VDM-P (for printer image)
Check the following readings in service mode:
COPIER>DISPLAY>DPOT>VL1M (for copier image)
COPIER>DISPLAY>DPOT>VL1M-P (for printer image)
Check the following readings in service mode:
COPIER>DISPLAY>DPOT>VL2M (for copier image)
COPIER>DISPLAY>DPOT>VL2M-P (for printer image)
Adjust the offset of the VD target potential.
COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON iR5000i/iR6000i REV.0 JUNE 2001
Density>
Generate a solid black print.
Is the density
NO
too low or too high (too
light or too dark)?
YES
Are the
Check the primary charging
NO
readings ± 6 V of the
system; if normal, replace the
target value?
photosensitive drum.
(*1)
YES
Check the following, and replace them if
Are the
necessary:
NO
readings ± 6 V of the
1. Laser (for output)
target value?
2. Potential control system
(*2)
3. Photosensitive drum
YES
Check the following, and replace them if
NO necessary:
Are the readings
1. Laser (for output)
70 ± 15 V?
2. Potential control system
3. Photosensitive drum
YES
CHAPTER 2 IMAGE ADJUSTMENT BASIC PROCEDURE
<Checking the Halftone Density>
Generate a halftone image.
YES
Is the halftone
End.
density optimum?
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.
REF.
*1:VD target value
COPIER >DISPLAY >DPOT >VDT (for copier image)
COPIER >DISPLAY >DPOT >VDT-P (for printer image)
*2:VL1 target value
COPIER >DISPLAY >DPOT >VD1T (for copier image)
COPIER >DISPLAY >DPOT >VD1T-P (for printer image)
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)
Lighter image
Default
-5 -4 -3 -2 -1 0
Darker image
+1 +2 +3 +4 +5
2-3 T