4090-001
Encoder Sensor Test
This test disables the printer motors to allow you to manually move the carrier to verify the encoder is working correctly.
To run the test:
1.Turn the printer off and place a two pin jumper on connector J6 as shown below. (Pins 1 & 2)
2.Press and hold the Paper Feed 
button while turning the printer on, to start the test. Release the button when the printer completes POST. Turn power off or unplug the printer to stop the test.
The power light flashes as the carrier is moved. The busy light remains on for right to left, and blinks for left to right movement. With no carrier movement, the busy light indicates the direction of the last move. If the test fails, power off the printer and remove the carrier assembly without unplugging the printhead cable.
Power on the printer and check for +5 V dc at pins 1, 2 and 3 of the encoder card connector.
1.If voltage is not present, check the printhead cable for opens to the encoder card. If the printhead cable is good, replace the system board.
2.If voltage is present, check the sensor on the encoder card by monitoring pin 3 of the encoder card connector as you pass a piece of paper through the sensor. The voltage should go from +5 V dc to 0 V dc. Turn the power off and back on to make this check again. If the voltage at pin 3 does not change, replace the encoder card. If the symptom remains, replace the printhead cable.
Diagnostic Aids