Making Checks On The Scanner Side (Ir8500) - Canon iR8500 Service Manual

CHAPTER 6 TROUBLESHOOTING

1.1.4 Making Checks on the Scanner Side (iR8500)

<Making Image Initial Checks>
Are there a
NO
horizontal lines in
the image?
YES
Clean the following:
1. Mirrors
2. Lens
3. Standard white plate
4. Copyboard glass
Execute shading in service mode:
1. COPIER>FUNCTION>CCD>CCD-ADJ
2. COPIER>FUNCTION>CCD>LUT-ADJ
<Checking the Halftone Density>
B
Make a copy of the
A3 Chart in text/photo mode; is
YES
the density of No. 8 appropriate
when compared with No. 7
through 9 on the
Test Chart?
If too dark,
NO
If too light,
Decrease the setting of the
Increase the setting of the
following in service mode:
following in service mode:
COPIER>ADJUST>DENS>
COPIER>ADJUST>DENS>
DENS-ADJ.
DENS-ADJ.
Make a single copy
of the A3 Chart
in text/photo mode.
Does
the density of No. 8
(halftone) of the gray
YES
scale change?
NO
Check the halftone density on the printer side.
6-6
<Checking the Density Slope> <Checking the Solid Black Density>
Is there a
NO
difference in density
between front and
rear?
YES
Check how the
standard white plate
is mounted. If not in
firm contact, correct
it.
Execute shading in service mode:
Execute potential
1. COPIER>FUNCTION>CCD>CCD-ADJ.
control.
2. COPIER>FUNCTION>CCD>LUT-ADJ.
Execute shading in service mode:
1. COPIER>FUNCTION>CCD>CCD-ADJ
Is there a
NO
2. COPIER>FUNCTION>CCD>LUT-ADJ
difference in density
between front and
rear?
End.
YES
Perform the instructions
under "Checking the Density
Slope" for the printer unit.
<Checking for Fogging>
Make a copy of
the NA3 Chart in test mode. NO
the NA3 Chart in text mode.
Is gray scale No. 1 (solid black)
Is the white background
of the gray scale
light?
YES
Check the scanning lamp.
If it has reached the end
of its life, replace it.
Clean the following:
1. Mirrors
2. Lens
3. Standard white plate
4. Dust-proofing glass
5. Scanning lamp
6. Reflecting plate
Turn off and then on the
the NA3 Chart in AE mode.
power switch.
Is the output foggy?
Is the
density of gray
NO
scale No.1 (solid black)
too low (light)?
YES
Check the solid black
density on the printer
side.
F06-101-04
COPYRIGHT© 2001 CANON INC.
Execute shading adjustment in service
Make a copy of
mode:
YES
1. COPIER>FUNCTION>CCD>CCD-ADJ
2. COPIER>FUNCTION>CCD>LUT-ADJ
foggy?
NO
Is the white area
foggy?
YES
Make the following selections, and
increase the setting:
COPIER>ADJUST>CCD>SH-TRGT.
(Limit the increase to 160.)
Execute shading adjustment in service
Make a copy of
YES mode:
1. COPIER>FUNCTION>CCD>CCD-ADJ
2. COPIER>FUNCTION>CCD>LUT-ADJ
NO
NO
B
Is the white area
foggy?
YES
Decrease the value of AE density
adjustment in service mode:
COPIER>ADJUST>AE>AE-TBL>
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
NO
Check for
fogging on the
printer side.