Citizen CBM-920 Service Manual page 9

4 4 4 4 - - - - 2 2 2 2 T T T T r r r r o o o o u u u u b b b b l l l l e e e e s s s s h h h h oo oo oo oot t t t i i i i n n n n g g g g G G G G u u u u i i i i d d d d e e e e
Phenomenon
Printing failure
No printing
Thin printing
color
Missing dots
Bad printing
quality
Paper feed failure
A printing paper
feed motor does
not function or
malfunctions.
The printing
paper is not fed
or fed
irregularly.
Faulty sensor
Does not detect
the printing
paper.
When the trouble
still persists
* For the printer mechanism MD910 series, see the Service Manual separately provided.
Cause
Faulty power supply
Faulty mounting and
connection of an interface
cable
Faulty printer
mechanism
Faulty power supply
Foreign substance
adhered to a printing
head
Faulty ribbon
Faulty connection of a
motor connector
Faulty power supply
Faulty printer
mechanism
Paper feed failure
Foreign substance in the
gear
Broken gear
Faulty paper sensor
Check Method
Check whether 5 V DC is
available.
Check mounting and
connection of the interface
cable.
Check whether a 5 V DC
power capacity is sufficient.
Check the head for any
adhered foreign substance.
Check connection of the
connector.
Check whether a 5 V DC
power capacity is
sufficient.
Check whether or not the
printing paper is jamming
or torn and caught in a
paper path.
Check the motor gear of
the printer mechanism for
any foreign substance.
Check the motor gear for
breakage.
Check the window of
the paper sensor for any
foreign substance.
Replace the control
board and check
whether the printer
functions properly.
9
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CBM-920 Service Manual
Remedy
Supply 5 V DC.
Connect the interface
cable correctly.
Replace the printer
mechanism unit.
Use the power source
with a sufficient capacity.
Eliminate the foreign
substance.
Replace the ribbon.
Connect the connector
correctly.
Use the power source
with a sufficient capacity.
Replace the printer
mechanism.
Eliminate unnecessary
printing paper and re-set
it correctly.
Eliminate the foreign
substance.
If broken, replace the
printer mechanism.
Eliminate the foreign
substance or replace the
printer mechanism.
Replace the control
board.
CITIZEN