Samsung ML-1740/XSH, Service Laser Printer Ml-1740/Xsh Manual, Page: 79 / 107

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Samsung Electronics
T RO U B L E S H O OT I N G
Service Manual
Fault Signs Cause & Check Solution
White Black spot
Recycled product
• Light or dark black
dots on the image
occur periodically.
• White spots occur
in the image period-
ically.
• Poor appearance of
the developer.
• Unclean and rough
printouts.
• Bad background in
the image.
1. If light or dark periodical black
dots occur, this is because the
developer rollers are contami-
nated with foreign substance
or paper particles.
(1)37.7mm interval : Charged
roller
(2)75.5mm interval : OPC cycle
2. If white spots occur in a black
image at intervals of 75.5mm,
or black spots occur else-
where, the OPC drum is dam-
aged or foreign substance is
stuck to the surface.
3. If a black and white or graphic
image is partially broken at
irregular intervals, the transfer
roller's life has been expired or
the transfer voltage is abnor-
mal.
1. Poor appearance of the devel-
oper.
(1)Check the damage to label
and whether different materi-
als are used.
(2)Check the appearance of
parts of the developer, such
as frame, hopper.
2. Unclean and rough printouts.
(1)Check whether foreign sub-
stance or toner are stuck to
the terminal (contact point) of
the developer.
(2)Check whether the state of
the terminal assembly is nor-
mal.
1. In case of 1 above -
Run OPC Cleaning Mode Print
4-5 times repeatedly to remove.
Especially check foreign sub-
stance on the OPC surface, then
remove them with a clean gauze
moistened with IPA(Isopropyl
Alcohol) not to damage OPC if
necessary.
Never use usual alcohol.
2. In case of 2
If they are not disappeared by
running OPC Cleaning Mode
Print 4-5 times.
: at intervals of 37.7mm - Replace
the developer.
: at intervals of 75.5mm - Remove
foreign substance.
: Broken image - Replace the
developer according to careless-
ness.
3. In case of 3 - Exchange the
transfer roller because the life of
the transfer roller in use has been
expired. (Check the transfer volt-
age and readjust if different.)
1. In case of 1 -
(1)If there is an evidence of disas-
sembling the developer.
(2)If materials other than normal
parts of the developer are
added or substituted.
2. In case of 2 - If there are any
abnormals in connection with the
situation of 1.
(1)It occurs when the developer
is recycled over 2 times.
(2)If toner nearly being expired
are collected to use, it is
judged as the recycled devel-
oper.
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