LQ-670 Service Manual
Rev. A
5-17
5.5 Repairing the Printer Mechanism
This section provides instruction for repairing the printer mechanism. It describes various problems,
symptom, likely causes, checkpoints, and solutions.
Symptom
Condition
Cause
Checkpoint
Solution
CR motor is
abnormal
CR does not move
even the power is
turned on.
Foreign objects
are attached to
mechanism.
Move the timing belt
manually and check if the
motor rotates or not.
Remove the
foreign objects.
CR motor is
defective
Measure the coil
resistance of the motor.
3.5
Ω±
10%.
(Refer to Table 5-5)
•
If the motor gets short-
circuit, check if the driver
circuit also got short-
circuit.
Replace CR
motor or main
board.
Carriage does
not move even
after the
power is
turned on.
CR motor rotates,
but carriage does
not move.
The pulley drive
is defective.
Check if the pulley is
broken or worn out.
Replace the
pulley drive.
Timing belt is
defective.
Check if the timing belt is
installed on the carriage,
also, the notched part of
the timing belt is worn out
or not.
Replace the
timing belt or re-
install again.
Carriage moves to
left side a little bit,
but stops.
Carriage does
not move
smoothly.
Check if carriage moves
smoothly by hand.
Clean CR guide
shaft and
lubricate it, or
replace the CR
motor.
Carriage stops after
moving to the right
or left edges.
HP sensor is
defective.
---
Replace the HP
sensor.
Printing is
abnormal.
Carriage moves but
no image is printed.
Head FFC is
disconnected or
there is no
continuity.
Check if head FFC is
connected or bent.
Replace the
FFC.
Print head is
defective
Measure head coil
resistance. 39.3
±
2.7
Ω
Replace the print
head(If
necessary
replace the
driver)
The printer does
not print a particular
dot.
Print head is
defective.
Check if the head wire is
broken or not.
Replace the print
head.
Printing result is
uneven or too light.
Print head is
defective
Check if the head wire is
broken or not.
Replace the print
head.
Abnormal
paper feed.
Printing is
performed, but no
paper feed, or
paper feed is not
done smoothly.
Foreign objects
are in the paper
path.
Check the paper path
visually.
Remove the
foreign objects.
PF motor is not
driven correctly.
Check if foreign objects
are attached to the motor
or drive gear, or gears are
damaged or worn out.
Remove the
foreign objects or
replace the
gears.
Table 5-14. Repairing the Printer Mechanism
Summary of Contents for LQ 670 - B/W Dot-matrix Printer
Page 1: ...EPSON IMPACT DOT MATRIX PRINTER EPSON LQ 670 SERVICE MANUAL SEIKO EPSON CORPORATION 4007875 ...
Page 5: ...v REVISION SHEET Revision Issued Data Contents Rev A May 28 1997 First issue ...
Page 114: ...Chapter 6 Maintenance 6 1 Preventive Maintenance 6 1 ...
Page 116: ...LQ 670 Service Manual Rev A 6 2 Figure 6 1 Lubrication Points ...
Page 122: ...LQ 670 Service Manual Rev A A 5 A 2 Circuit Diagram Figure A 2 C214Main Board Circuit Diagram ...
Page 123: ...Appendix Rev A A 6 Heat Sink Q1 D51 Figure A 3 C214PSB Board Circuit Diagram ...
Page 124: ...LQ 670 Service Manual Rev A A 7 Heat Sink Q1 D51 Figure A 4 C214PSE Board Circuit Diagram ...
Page 125: ...Appendix Rev A A 8 A 3 Component Layout Figure A 5 C214 Main Board Component Layout ...
Page 127: ...Appendix Rev A A 10 A 4 Exploded Diagram Figure A 8 Exploded Diagram ...
Page 128: ...LQ 670 Service Manual Rev A A 11 Figure A 9 Exploded Diagram ...
Page 129: ...Appendix Rev A A 12 Figure A 10 Exploded Diagram ...
Page 135: ...EPSON SEIKO EPSON CORPORATION ...
