Service manual

TROUBLESHOOTING GUIDE 2
SM 4-47 G130/G131
Subject Symptom Cause Action
Symptoms related to color
Faint image (black) Only black becomes lighter. The transfer belt position is not in the
correct position.
Check the transfer belt unit position and/or the
transfer belt unit release lever.
Magenta and/or cyan
jitter
Magenta jitter may appear at
81 mm and/or cyan jitter at
162/ 125 mm from the trailing
edge.
If the registration roller speed is too fast
for the paper types used, the shock
when the trailing edge has just passed
the registration roller generates
vibration, causing the jitter.
This may appear especially when using
thick paper because of its stiffness.
Adjust the registration roller speed depending on
the paper types and/or mode selected.
SP1-004-4: Normal paper (1200 dpi)
SP1-004-5: Normal paper (600 dpi)
SP1-005-3: Thick paper (1200 dpi)
If SP1-005-3 cannot improve the level even when
setting it to “-1.0”, follow the procedure below.
1. Set SP1-005-3 to “-1.0”.
2. Print the samples by adjusting SP1-004-4 from
100% (-0.2% to -0.8%).
After adjusting SP1-004-4, check the image
quality also with normal paper in the 1200 dpi
mode. Readjust it so that the image quality
level is acceptable for both thick and normal
paper if necessary.
Toner blasting (1) Toner may blast, causing
smeared text characters
and/or lines in 2C or process
black mode (depending on
the PDL setting or type of
paper used.)
An excessive amount of toner is used for
development.
Change the toner limit setting in SP mode.
• If toner blasted images appear for text or lines
in 2C, decrease the setting for Text from 190%
to 150 - 170%.
• If toner blasted images for text and lines
recognized as pure image data (i.e. not
processed as text/line data), decrease the
setting for Photo from 260% to 170 - 190%.
NOTE: If the toner limit is lowered too much, it
may cause the density of shadow areas to
be not smooth.