Knowledge Base

Table of Contents:

1. Principle of Operation
2. Test Sensor Operation
3. Test Actuator A
4. Test Actuator B

This article provides information on "Troubleshooting the 3130cn / 3130cdn Dell Laser Printer Registration Sensor"

1. Principle of Operation

The registration sensor detects the leading edge of the paper arriving at the registration assembly. If the registration sensor is damaged, stuck, or otherwise operating incorrectly it can cause paper jams to occur.

Location of the registration assembly.

Detail of the registration sensor within the registration assembly.

The registration sensor is optical. It is triggered by an actuator arm passing through the area the sensor monitors. As the paper path through the registration assembly is different depending on whether the paper is fed from a paper tray or the Multi Purpose Feeder (MPF) the sensor has two actuators. The image below shows the normal position of the actuator arms. No paper is present and actuator A is blocking the optical sensor.

When paper is fed from the MPF, or is returned from the duplex paper path, it enters the registration assembly from the front. While paper is present actuator A is pushed back and no longer blocks the optical sensor. When the paper has passed the actuator springs back into it's normal position.

When paper is fed from tray 1 or 2 it enters the registration assembly from the rear. While paper is present actuator B is pushed back, which pushes actuator A clear of the optical sensor. When the paper has passed both actuators spring back into their normal positions.

More info can be found in the 3130cn User’s Guide.

2. Test Sensor Operation

The sensor is tested by manually moving the actuators and checking the value returned by the sensor. To enter the diagnostic menu, also known as "Customer Mode".

1. Switch the power off.
2. Press and hold the Up and Down arrows on the printer control panel.
3. With the buttons still held down, switch the power back on.
4. When Diagnosing is displayed on the screen release the buttons. Once the installation on the screen displays Customer Mode on the top line and IOT Diag on the bottom line.
5. Press the Tick/Select button to select IOT Diag.
6. Select Digital Input.
7. Press the Down arrow until DI-3 OFF is displayed. Press Tick/Select.
8. The screen displays DI-3 L 1 or DI-3 H 1.
   • The letter following DI-3 indicates whether the sensor detects paper is present. If no paper is detected the letter L is displayed. If paper is detected the letter H is displayed.
   • The number following DI counts the number of times the sensor value has changed since the test began. The number increases each time the letter changes from H to L.
9. If the test initially returns H check for scraps of paper or damage in or around the registration assembly.
10. Follow the instructions in sections 3 and 4 to check the operation of the sensor and actuators.

More info can be found in the 3130cn User’s Guide.

3. Test Actuator A

Actuator A is tested by manually inserting paper into the registration assembly.

1. Remove tray 1 completely.
2. Locate the front entrance to the paper path.
   
   
3. Actuator A is visible under close examination in good light.
   
   
4. Insert a sheet of paper. When paper is inserted the operator panel should display the letter H. When the paper is removed letter should change back to L.
   
   

More info can be found in the 3130cn User’s Guide.

4. Test Actuator B

Actuator B is tested by manually lifting the actuator with a finger.

1. As actuator B is on the rear of the registration assembly it is not visible when the part is installed in the printer. The image below shows a registration assembly removed from the printer, the location of actuator B is highlighted in red.
   
   
2. Detail of Actuator B being lifted on removed assembly.
   
   
3. To test the sensor with the registration assembly in place, open the front door and remove the yellow toner cartridge. Reach behind the registration assembly and locate the actuator by touch. When the actuator is lifted the operator panel should display the letter H. When the actuator is allowed to fall it should return to L.
   
   

More info can be found in the 3130cn User’s Guide.

If these steps do not correct the problem, please contact Dell Technical Support.