Epson LQ-1170 Service Manual page 109

Table 5-6. Repair of the Printer Mechanism (Continued)
Problem
Self-test printing
is A
abnormal. fails to print.
The printing is too
light, or the print
density is not
uniform.
Paper feeding is Printing is per-
formed, but the pa-
abnormal.
per is not fed, or is
not fed uniformly.
Symptom
particular dot The printhead is
defective.
The printhead is
defective.
The platen gap is
not properly
adjusted.
Foreign substances
are lodged in the
paper path.
The paper-feed mo-
the gear correctly.
The paper-feed mo-
.
Checkpoint
Cause
Measure the
mal value is ap-
proximately 45.5
ohms.
Check whether the
dot wire is worn.
Check whether the
tip of the dot wire
is worn.
Set the gap adjust
lever to the second
position, and check
between
the gap
the tip of the print-
head and the
platen.
The appropriate
value is 0.38 mm.
Perform a visual
check
of the paper
path.
Check that no for-
lodged between
the gears, and that
the gears are not
broken or worn.
Measure the coil re-
per feed-motor.
The approximate
value should be 79
ohms.
5 - 2 0
Solution
coil re-
Replace the
Replace the
Replace the
Adjust the gap.
Refer to Section
4.1.2, Platen Gap
Adjustment.
Remove any for-
. Remove any for-
. Replace the pa-
per-feed reduc-
tion gear.
Replace the plat
en gear.
Replace the paper-
feed motor.