Casio UP-250 Technical Manual page 88

Table 4-2 Troubleshooting table for bad printing (continued)
Problem Probable cause
Dots are The head FPC may
missing be bad.
occasionally.
The print head unit
may be bad.
The print head unit
may be worn.
The character Paper particles or
width is foreign substances
incorrect. may be attached to
gears, belt driving
pulley, or the belt.
The gears, belt driving
pulley, or the belt may
be damaged or worn.
Paper is not The operation of the
fed.(Printing is paper supply may be
performed on incorrect.
one line.)
The paper path may
be incorrect.
The connector is not
inserted correctly.
The paper feed roller
may be bad.
The paper hold roller
assembly may be
worn or damaged.
Paper is not Gears may be worn
fed. (Printing is or damaged.
performed on
one line.)(cont.)
Paper feed motor
assembly may be
bad.
The paper feed
motor may be bad.
Level Checkpoint
Check the continuity of the
B
head FPC.
B
Check if there are paper
particles or ink on the tips of the
dot wires of the print head unit.
B The cause is none of the
above.
B
Check if any paper particles
or foreign substances are
attached to the belt driving
pulley, belt tension pulley,
and belt.
B Check for wear and damage
in the belt driving pulley, belt
tension pulley, and belt.
Check if the specified paper
A
roll is used.
A
Check if the paper supply
path is blocked.
A Make sure that the PF motor
cable pins are inserted in
connector CN6 of the main
circuit board.
B
Check for wear and damage
on the surface of the roller.
B Check for wear and damage
to the rollers of the paper
hold roller assembly.
B
Check for wear and damage
to the paper feed reduction
gear and paper feed gear.
B
Check the continuity of the
PF motor cable assembly.
B The cause is none of the
above.
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Action
Replace the head FPC.
Remove any paper
particles or ink, or replace
the print head unit.
Replace the print head
unit.
Remove any paper
particles or foreign
substances.
Replace any worn or
damaged parts.
Use the correct paper roll.
(See "Paper Specifications"
in Chapter 1.)
Remove paper particles
and foreign substances.
Reinsert the connector.
Replace the paper feed
roller.
Replace the paper hold
roller assembly.
Replace any worn or
damaged parts.
Replace the paper feed
motor cable assembly.
Replace the paper feed
motor.