Epson LQ-570 Service Manual page 40

REV.-A
Problem
Self-test printing
A particular dot
is abnormal. fails to print.
The printing is too
light, or the print
density is not
uniform.
Paper feeding is
Printing is
abnormal.
paper is not fed, or
is not fed uniformly.
Symptom
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
motor is not driving
the gear correctty.
The paper-feed
motor is defective.
(Continued}
Cause Checkpoint
Measure the coil
resistance of the
normal value is
approximately
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
the gap between the
and the platen.
The appropriate
value is 0.48 mm.
check of the paper
path.
Check that no foreign
substance is lodged
between the gears,
and that the gears
are not broken or
worn.
Measure the mil
resistance for the
paper feed motor.
The approximate
value should be
ohms.
5-18
Solution
45.5
Replace the
Replace the
Adjust the gap.
Refer to Section
4.1.2, Platen Gap
Remove any
foreign
substances.
Remove any
foreign substance.
paper-feed
reduction gear.
Replace the
platen gear.
Replace the
paper-feed motor.
79
.