Epson FX-870 Service Manual page 56

[WIRE ASSIGNMENT]
Note: The commons correspond to the following
printhead dot wires:
Table 3-4. Printhead Test Points and Coil Resistance
Common
Connector Pin
Number
Numbers
Printhead 2
8
14
Thermistor
E p s o n FX-870/1170
[ T E R M I N A L A S S I G N M E N T ]
Figure 3-1. Printhead Resistance
Connector
(Set Meter to Ohms. Disconnect
Test Pin Printhead and Check it with
Numbers
Place one lead on pin 2 and the other on
test pins
resistance of printhead dots #2, #4, and #6.
Place one lead on pin 8 and the other on
test
pins
resistance of printhead dots #7, #8, and #9.
Place one lead on pin 14 and the other lead
on each of the test pins 10, 11, and 12 to
check the resistance of printhead dots
Place one lead on each pin.
1
COM. 2 = #2, #4, #6
COM. 8 = #7, #8, #9
COM. 14=#1,#3,#5
Test Method
Printer Power Off.)
and 5 to check the
4, 6, and 13 to check the
Troubleshooting
Note:
The printhead is
upside down in
this illustration.
Meter Reading
(at 77" F,
25" C)
Approx. 9.3 K R
3-3