Service manual

REV.-A
Table 5-6. Repairing the Printer Mechanism (Continued)
Problem
symptom
Cause
Checkpoint
Solution
Self test printing
The carriage
The
common wires
Check the common
Replace the FFC.
abnormal.
moves, but the self- in the printhead FFC
wires in the
test printing is not
are disconnected, or
printhead FFC.
executed.
there is no
continuity.
The printer does
The printhead is Measure the coil
Replace the
not print a
defective.
resistance of the
printhead. (If any
particular dot.
printhead. The
pin is shorted, also
resistance should
check the drivers
be approximately
on the main board.
16.5 ohms.
Check if the dot
Replace the
wire is worn.
printhead.
The printing is too The
printhead is Check if the tip of
Replace the
light or the print defective. the dot wire is
printhead.
density is not
worn.
uniform.
The platen gap is
Set the LEVER, G.
Adjust the gap as
not adjusted
ADJUST to O and described in
properly. check the gap
“Platen Gap
between the the
Adjustment” in
printhead and the Chapter 4.
platen. The correct
gap is 0.36-0.40
mm.
Paper feeding The printer prints
Foreign substances Visually check the Remove any
abnormal.
but does not feed
are lodged in the paper path for any
foreign
paper properly.
paper path. foreign substances.
substances.
The MOTOR ASSY,
Check the gears for
Replace the
PF is not driving
damage or wear.
defective gear.
the gear correctly.
The MOTOR
ASSY.,
Measure the coil
Replace the MOTOR
PF is defective.
resistance of the
ASSY., PF. (If any
MOTOR
ASSY., PF.
coil is shorted, also
The resistance
check the drivers on
should be
the main board.
approximately 63
ohms.
5-19