I. MAINTENANCE AND INSPECTION
A. Image Adjustment Basic Procedure
n
Non-AE, Copy Density at 5
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
11-3
Is there a
difference in density
between front
and rear?
Is it low (light)
at the rear?
Turn the adjusting screw
at the rear of the primary
charging assembly
clockwise, and turn the
adjusting screw at the
front counterclockwise
the same degree (1.5 mm
max. each).
Make two to three
copies of the Test
Sheet.
Check the height of the
charging wire.
Turn the adjusting screw
at the rear of the primary
charging assembly
counterclockwise, and
turn the adjusting screw
at the front clockwise the
same degree (1.5 mm
max. each).
Turn off and then on the
machine, and make a
copy.
Note 1: If the difference still exists after turning the screw
1. 5 mm (each; a full turn causes a 0.7mm
difference), check the charging assemblies,
scanning lamp, and scanner for dirt.
Note 2: When turning the screw counterclockwise, take
care so that the wire is not 7.5mm or less in
height.
Check the copy paper
and the transfer system.
Is the density
of gray scale No. 1
too low (light)?
Clean the standard white
plate, mirror, lens, dust-
roofing glass, scanning
lamp, reflecting plate, and
heat absorbing glass.
Turn off and then on the
machine, and make a
copy.
Is 'VDM' 'VDT'
±10 V?
Is 'PLMT' '1'?
Is 'VL1M' 'VL1T'
±10 V?
Is 'VL1M" 'VL1T'
±10V?
Check the potential
control system; if
normal, replace the
photosensitive
drum.
Check the scanning
lamp and the
potential control
system; if normal,
replace the
photosensitive
drum.
Increase the value of
'VDT-SW'.
Turn off and on the
machine, and make a
copy.
Increase the value of
'LIGHT_5'.
Decrease the value of
'LIGHT_5'.
Is the density
of gray scale No. 10
proper?
Is the density
of gray scale No. 10
too high (dark)?
Execute AE adjustment.
(See p. 11-36.)
<Pre-Checks>
<Density slope>
<
Solid black
>
NO
YES
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
NO
YES
*
1
*
*
3
*
*
5
*
Clean the charging wire.
Make a copy.