Troubleshooting Items; Image Faults; Smudged/Streaked - Canon imageCLASS MF4890dw Service Manual

Troubleshooting Items

Image Faults

■ Smudged/Streaked

● Bleeding (smear) occurs immediately after the power is turned on for
the first time for the day
Description
There is sometimes a case where the difference of temperature between air and inside of the
machine causes moisture to occur on the toner immediately after the power is turned on for
the first time for the day.
As a result, when the toner transferred on a sheet at the time of initial printing passes through
the fixing assembly, moisture on the toner is vaporized into steam, causing breading (smear)
to occur.
Field Remedy
Prevent bleeding using the following user mode items.
Setting items Setting value
Adjustment/ Not used,Mode 1 Make a setting to perform
Maintenance > through 4 (Factory thinning of printed image
Special Processing setting: Mode 2) data by processing of the
> Special Mode Z controller. When the value
set for the mode increases,
the amount of thinning
increases. (The image
density decreases.)
Adjustment/ Not used,Mode 1 Extend the initial rotation
Maintenance > through 3 (Factory period by processing of the
Special Processing setting: Not used) engine. When the value
> Special Mode B set for the mode increases,
the initial rotation period is
extended.
6
Troubleshooting > Troubleshooting Items > Image Faults > Smudged/Streaked
Description Additional information
Printing time does not
increase because the
method of image processing
performed by the controller
is changed. This mode is
less effective than Mode B.
The initial rotation period
in engine operation is
extended, and printing time
increases. The initial rotation
period for each mode is
shown below. Mode 1: 13
sec, Mode 2: 30 sec, Mode 3:
60 sec
6 Troubleshooting > Troubleshooting Items > Image Faults > Smudged/Streaked
Image sample
T-6-1
6-3
F-6-2
6-3