Specifications

REV.-B
Table 5-5. Repair of the PRINTER MECHANISM (Cont.)
Problem
Symptom
Cause
Checkpoint
Solution
Self-test printing is
A particular dot
The printhead is
Measure the coil re- Replace the
abnormal.
fails to print. defective.
sistance of the printhead.
printhead. The nor-
mal value is ap-
proximately 45.5
ohms.
Check whether the
Replace the
dot wire is worn.
printhead.
The printing is too The printhead is
Check whether the Replace the
light, or the print defective.
tip of the dot wire printhead.
density is not
is worn.
uniform.
The platen gap is
Set the gap LEVER,
Adjust the gap.
not properly
G, ADJUST to the Refer to Section
adjusted.
second position,
4.1.2, Platen Gap
and check the gap
Adjustment.
between the tip of
the printhead and
the PLATEN.
The appropriate
value is 0.46 mm.
Paper feeding is
abnormal.
Printing is per-
Foreign substances
Perform a visual
Remove any for-
formed, but the pa- are lodged in the
check of the paper eign substance.
per is not fed, or is paper path.
path.
not fed uniformly.
The MOTOR, PF is
Check that no for- . Remove any for-
not driving the
eign substance is eign substance.
gear correctly.
lodged between
. Replace the pa-
the gears, and that per-feed reduc-
the gears are not
tion gear.
broken or worn. . Replace the plat
en gear.
The MOTOR, PF is
Measure the coil re-
Replace the MO-
defective.
sistance for the
TOR, PF.
MOTOR, PF.
The approximate
value should be 79
ohms.
5-18