Gestetner B147 Service Manual page 258

TROUBLESHOOTING GUIDE
(From previous page)
Problem is related to
the scanner section.
from SBU in SP4-
907 in each colour.
from IPU in SP4-417
by selecting related
Check connection
between the IPU/
Faint image (K)
Check the image transfer unit position lever.
Cyan/Magenta jitter
Check if the registration roller speed is suitable for the type of paper used.
Toner blasting
Check which colour is blasting and adjust the toner limit or transfer bias.
Image density change
Check when the problem is reported and follow the necessary steps.
Dirty Background
Check in which condition the problem is reported, and follow the required procedure.
Colour vertical bands/lines/dirty background
Check the OPC drum and/or development unit.
Colour shift
Check the level of the colour shift and follow the troubleshooting guide if required.
Colour lines/bands/dirty background
When the PCU/development unit is close to its life end, the developer or the cleaning blade of the
PCU wears out, causing vertical colour lines, bands, or dirty background. Check the related colour
unit and replace it if necessary.
B147/B149/B190
A
Make a test print
Can the
problem be
duplicated?
No
Yes
Make a test print
colour.
Can the
problem be No
duplicated?
Yes
Controller, or
replace the IPU.
Considerable Symptom
Possible Symptoms
Colour shift
Check the level of the
colour shift and follow
the troubleshooting
guide if required.
Check Points
Connection of flat cable
between the controller
and laser optic housing
unit.
Mirror position of related
colour located in the laser
optic housing unit.
Controller or BCU board
defective
Check the scanner section
(exposure glass, mirrors,
scanner movement, etc.)
Check the connection
between the SBU/IPU or
replace the SBU.
4-56
B
Yes
All colour?
No
Yes
Colour missing
No
Specify the colour
that caused the
image problem.
Check the image
processing area of
the colour specified
in the previous step
B146T902.WMF
SM