Troubleshooting; Overview; Troubleshooting Information; Printhead - Epson 2070 - LQ B/W Dot-matrix Printer Service Manual

LQ-2070 Service Manual

5.1 OVERVIEW

This chapter contains flowcharts and checkpoint tables to help you troubleshoot the printer. Flowcharts let
you isolate a faulty unit based on abnormal symptoms. The checkpoint tables let you identify the faulty part
or unit by checking the values or ranges listed for each component.

5.2 TROUBLESHOOTING INFORMATION

This section gives troubleshooting information to let you check test points for replaceable units.

5.2.1 Printhead

5-1. Printhead Coil Resistance Test Points
Common
Pin No.
Refer to the
Refer to the
following figure.
following figure.
F
C O M.
C 2
2,6,10,18
Pin No,
T : Thermistor terminal
C1~C6 : Common terminal
1~24 : Wire number
Figure 5-1 Printhead Connected Pin Alignment
Rev.A
Test
(Set meter to ohms. Disconnect
Pin No.
the printhead after the printer is
Place one lead on each pin and the
other lead on each common pin.
3 1 1
R
5 1 1 3
R
C 3
C6
3,7,11,15
14,22,19,23
Test Method
powered off.)
R
2 19 7 C 3 C 6 C 2 1 8 23
2 2 1 5
F
9 2 1 1 7 C 5 C 4 C 1 2 4 2 0 1 2 8
F
C 1
C O M .
Pin No, 1,8,16,24
4,12,20,21

Troubleshooting

Meter Reading
39.3 ± 10% Ω
( at 25° C, 77° F)
1 0 1 4 6
1 6 T T 4
C 4
C5
5,9,13,17
5-1