Test Points - Epson FX-870 Service Manual

The information in this section can help you identify causes of printer problems and test the
printer to isolate the part that needs to be replaced. The chapter also contains illustrations
showing connector locations and sensor locations. Once you have read this chapter to
determine what tests you need to run on the printer, see Chapter 4 for instructions on how to
disassemble the printer.
Before disassembling the printer to perform any troubleshooting tests, disconnect the
power supply cable from the AC power outlet. Failure to do so may cause physical injury.
The power switch is wired in the secondary circuitry. Therefore, the printer's primary
circuitry remains live even after the power switch is turned off.
When performing the testing described in this chapter, do not connect the printer to the
power source unless instructed to do so in the test. When the power supply must be
connected, use extreme caution, because the voltage may cause physical injury and may
, damage the components of the printer.

Test Points

The test point tables and diagrams have been placed at the front of this chapter to provide you
with quick reference for checking motors, the printhead, printhead drivers, sensors, and the
a
power supply, if you suspect a problem.
Connector
Pin Numbers Check with Printer Power Off.)
11 and3 Place one lead on pin 11 and the other on
pin 3 (ground).
Power Supply
Connector
Pin Numbers
Check with Printer Power On.)
1 and3 Place the + lead on pin 1 (5 V) and the
Place the + lead on pin 9 (35 V) and the
CN2
E p s o n FX-870/1170
WARNING
Table 3-1. Power Supply Test Points
Test Method
(Set Meter to Continuity.
Test Method
(Set Meter to Volts.
Troubleshooting 3
Meter Reading
Continuity/open means OPERATE is activated
and you can check the power supply voltages.
Meter Reading
3-1