Service manual

Troubleshooting
5-6
EPSON FX-880/FX-1180 Service Manual
Sensors
You can test a sensor by disconnecting its cable connector from the main board and applying the meter’s
leads directly to the exposed (uninsulated) side of the connector.
Table 5-8. Sensor Test Points
Sensor
Connector
Number
Test Pin
Number
Test Method
(Set meter to ohms. Check that
printer power is off.)
Meter Reading
CN4
(HP Sensor)
1: HP
2: GND
Place one lead on pin 1 and the
other lead on pin 2, and check
the continuity while toggling the
sensor lever.
Short: Home position
Open: Not home
CN6
(Front PE
Sensor)
1: PE
2: GND
Place one lead on pin 1 and the
other on pin 2, and check the
continuity while toggling the
sensor lever.
Open: Paper loaded
Short: No paper
CN10
(Release Lever
Sensor)
1: RELEASE
2. GND
Place one lead on pin 1 and the
other on pin 2, and check the
continuity while toggling the
sensor lever.
Open: Friction feed mode
Short: Tractor mode (either push,
pull, or push and pull)
CN11
(PG Sensor)
1: PG 1
2: GND
Place one lead on pin 1 and the
other on pin 2, and check the
continuity while moving the
sensor lever from –0 to 6.
Meter should toggle between:
Open and Short.
(Open: PG –1 to 3)
Printhead
thermistor
T pins Place one lead on one pin T, and
the other on the second pin T to
check resistance. See Figure 5-2.
Approximately 14K Ω
(at 62.6° F, or 17° C)
Power Supply
The output voltages of the power supply can be measured by pulling out the flat cable (CN2) from
connector CN3 on the main board.
Table 5-9. Output Voltage of the Power Supply Board
Connector Pin Output voltage
1, 2 GP
3, 4 + 35 V
5, 6 GL
CN2 (flat cable
on the power
supply board)
7, 8 + 5 V
Note: The ground terminals GP and GL are connected and are not separate grounds.