Canon S820MG Service Manual page 198

S900/S9000/S820 issues
Issue
Repeating feed failure of all sizes of PC101
Occurs only in L/L environment. Extremely low
occurrence rate.
Edge of the page contacts head
The leading or trailing edge of the paper
contacts the head and leaves black traces.
1) Occurs with borderless paper
Misaligned printing may affect postcards.
2) Occurs with non-borderless normal and
HG-201 paper
Problem occurs with HG-201 even when the
paper lever is set to envelope thickness.
Note that there is no problem printing within
the recommended print area of
non-borderless paper.
Inappropriate color hues at quality settings of
1 (highest quality) and 2 (high quality)
Conspicuous with grey, barely noticeable with
other colors. Problem papers are GP301,
HR101.
In the borderless printing durability test,
staining of the reverse side of the paper
occurred. The right side ribs cannot be
cleaned.
Occurs at a low level when more than 3000
sheets (1000 borderless postcards) but, at an
unacceptably high level when 6000 sheets
(2000 borderless postcards) are fed.
This problem will only begin to affect the
average user (300 postcards per year) after 4
years or so, and so is not a major issue
Download Service Manual
Model Cause
All There is insufficient contact between the feed roller
and the separation pad, and if self-cleaning is not
performed to remove paper dust on the rubber of the
roller, the friction coefficient is lowered.
All (1) Due to the elimination of the paper depressor of
models to date in order to allow borderless printing.
(2) Paper curling (especially HG-201 after printing)
All Quality settings 2 (4 pass, uni-directional) and 1 (8
pass, bi-directional) use the same color parameters.
All Paper dust which absorbs ink particles
accumulates on the platen ribs and causes
staining. There are two causes:
(1) Significant paper dust accumulates from factory
sizing of Japanese postcards and KII201.
(2) Ink mist attaches easily to paper edges.
ManualsBooks
Countermeasure
When feeding problems (including repeating
failure) occur, perform feed roller cleaning 2
times.
(Note that excessive cleaning will wear out the
rollers)
1) Paper which supports borderless printing
* Have the user understand that there is the
possibility of ink stains at the leading and
trailing edges when borderless printing.
* Flatten curled paper.
* Set the paper thickness lever to envelope
thickness.
Recommend non-borderless printing with the
recommended print area.
Have the user understand that although
borderless printing is possible with normal
paper, it is not recommended.
As per specifications.
Cleaning method for after borderless printing
or the platen has been printed (purge side of
the platen):
1. Power the printer ON and open the access
cover.
2. With the head at replacement position,
remove the power cord.
3. Clean the purge-side platen ribs with Q-tips
etc.
Remarks