Sensors; Power Supply - Epson FX-880 Service Manual

Troubleshooting

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.
Sensor Test Pin
Connector Number
Number
CN4 1: HP
(HP Sensor) 2: GND
CN6 1: PE
(Front PE 2: GND
Sensor)
CN10 1: RELEASE
(Release Lever 2. GND
Sensor)
CN11 1: PG 1
(PG Sensor) 2: GND
Printhead T pins
thermistor

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.
Note: The ground terminals GP and GL are connected and are not separate grounds.
5-6
Table 5-8. Sensor Test Points
Test Method
(Set meter to ohms. Check that
printer power is off.)
Place one lead on pin 1 and the
other lead on pin 2, and check
the continuity while toggling the
sensor lever.
Place one lead on pin 1 and the
other on pin 2, and check the
continuity while toggling the
sensor lever.
Place one lead on pin 1 and the
other on pin 2, and check the
continuity while toggling the
sensor lever.
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.
Place one lead on one pin T, and
the other on the second pin T to
check resistance. See Figure 5-2.
Table 5-9. Output Voltage of the Power Supply Board
Connector Pin
CN2 (flat cable 1, 2
on the power
3, 4
supply board)
5, 6
7, 8
Meter Reading
Short: Home position
Open: Not home
Open: Paper loaded
Short: No paper
Open: Friction feed mode
Short: Tractor mode (either push,
pull, or push and pull)
Meter should toggle between:
Open and Short.
(Open: PG –1 to 3)
Approximately 14K
(at 62.6 F, or 17 C)
Output voltage
GP
+ 35 V
GL
+ 5 V
EPSON FX-880/FX-1180 Service Manual