HP LaserJet 1160, 1320, Service Manual

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3. Remove the main input tray (tray 2).

4.Push down on the green lever on the automatic two-sidedpath door on the front of the printer.

5.With both hands, grasp the side of the media that is most visible (this includes the middle), and carefully pull it free from the printer.


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6. Close the automatic two-sidedpath door.

7. Reinsert the main input tray (tray 2).

8. Open the automatic two-sidedpath door on the back of the printer.

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9.With both hands, grasp the side of the media that is most visible (this includes the middle), and carefully pull it free from the printer.

10. Close the automatic two-sidedpath door.


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Functional checks

This section includes five functional checks for troubleshooting.

Engine test

The engine test is used to verify that the print engine is functioning correctly. The formatter is bypassed during an engine test, so the engine test is useful for isolating printer problems. The engine test prints horizontal lines down the entire printable area of a page and is also useful for checking and adjusting registration.



Printing an engine test

The formatter must be connected to the ECU to perform an engine test.

The engine-testswitch is inside the left cover, below the formatter. To print an engine test, remove the left side cover (seeLeft-side cover), override the door interlock (SW 301), and then press theengine-testswitch (callout 1 inFigure 7-1. Location of engine-test switch). A single test page prints.

Printing a configuration page verifies that the formatter is working correctly.

Figure 7-1.

Location of engine-testswitch

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Half self-testfunctional check

The print process can be subdivided into the following stages:

image formation stage (charges the drum and writes a latent image to the drum with the laser)

development stage (forms a toner image on the drum)

transfer stage (transfers the image to paper)

cleaning stage (removes excess toner from the drum)

fusing stage (applies heat and pressure to make the image on paper permanent)

To perform a half self-testcheck

The purpose of the half self-testcheck is to determine which process is malfunctioning.

1.Print a configuration page.

2.Open the print cartridge access door after the paper advances halfway through the printer (approximately five seconds after the motor begins rotating). The leading edge of the paper should have advanced past the print cartridge.

3.Remove the print cartridge.

4.Open the print cartridge drum shield to view the drum surface. If a dark and distinct toner image is present on the drum surface, assume that the first two functions of the electrophotographic process are functioning (image formation and development). Troubleshoot the failure as a transfer or fusing problem.

To perform other checks

If there is no image on the photosensitive drum, perform these checks:

1.Make sure you removed the entire length of the sealing tape from the print cartridge before you installed the cartridge.

2.Perform a drum rotation functional check to ensure that the drum is rotating (see Drum rotation functional check ).

3.Perform a high-voltagepower-supplycheck. (See below.)


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Drum rotation functional check


The photosensitive drum, located in the print cartridge, must rotate for the print process to


work. The photosensitive drum receives its drive from the main drive assembly.


This test is especially important if refilled print cartridges have been used.

1.Open the print-cartridgedoor.

2.Remove the print cartridge.

3.Mark the drive gear on the cartridge with a felt-tippedmarker. Note the position of the mark.

4.Install the print cartridge and close the print-cartridgedoor. The startup sequence should rotate the drum enough to move the mark.

5.Open the print-cartridgedoor and inspect the gear that was marked in step 3. Verify that the mark moved.

If the mark did not move, inspect the main drive assembly to make sure that it is meshing with the print cartridge gears. If the drive gears appear functional and the drum does not move, replace the print cartridge.

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Heating element check



Paper passes between the heating element and a soft pressure roller to fuse toner to the paper.

1.Unplug the printer for at least ten minutes.

2.Verify that the thermistor connector is seated into both the printer chassis and the ECU.

3.Remove the heating element connector from the ECU. To measure the continuity of the heating element, measure the resistance between the two pins at the end of the cable.

Normal resistance is 25 ohms +/- 10 ohms for the 110 V printer and 80 ohms +/- 20 ohms for the 220 V printer.

If no resistance is measured, replace the fuser.

4.Remove the thermistor connector, and then measure the resistance between J206 pins one and two and between J206 pins three and four.

Normal resistance between both pairs of pins is 370K ohms +/- 50K ohms at 20° C (68° F).

5. If no resistance is measured, replace the fuser.


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High-voltagecontacts check

The high-voltagecontacts in the printer must have a good connection with the contacts on the print cartridge to provide the necessary voltages for the electrophotographic processes.

To check the print cartridge contacts

Remove the print cartridge and visually inspect the three connection points on the ends of the print cartridge: drum ground (callout 1), charging (callout 2), and developing roller (callout 3). If they are dirty or corroded, clean the connection. If they are damaged, replace the print cartridge.


Use only isopropyl alcohol to clean the connections.

Figure 7-2. Print cartridgehigh-voltageconnection points (right side)

Figure 7-3. Print cartridgehigh-voltageconnection points (left side)

To check the high-voltageconnector assembly

Visually inspect the cartridge connection points inside the printer to make sure that that they are not dirty or corroded. If the pins are dirty, clean them using isopropyl alcohol only.

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Wired network setup problemsolving

If the computer is unable to discover the HP LaserJet 1320n, HP LaserJet 1320tn, or

HP LaserJet 1320nw printer, perform the following steps:

1.Check the cables to ensure that they are properly connected. Check all of the following connections:

Power cables

Cables between the printer and the hub or switch

Cables between the hub or switch and the computer

Cables to and from the modem or Internet connection, if applicable

2.To verify that the network connection is active, perform the following steps:

Check the network light on the network (RJ-45)connector on the back of the printer.

If one of the lights is on solid, the printer is connected to the network.

If both network lights are off, check the cable connections from the printer to the gateway, switch, or hub to ensure that the connections are secure.

If the connections are secure, turn off the power to the printer for at least 10 seconds, and then turn on the power to the printer.

3.To print a Network Configuration page, press the network Reset button located on the back of the printer.

Figure 7-4. Network Reset button

On the Network Configuration page, check to see if a non-zeroIP address is assigned to the printer.

If the Network Configuration page does not have a valid, non-zeroIP address, reset the Internal HP Jetdirect print server to the factory defaults. To cold reset the Internal HP Jetdirect print server, turn off the printer. While pressing the Reset button on the back of the printer, turn on the printer. Continue to press the Reset button until the printer is in the Ready state (from 5 to 30 seconds).

Five minutes after the printer reaches the Ready state, print another Network Configuration page, and check to see if a valid IP address is assigned to the printer.

If after 30 minutes the IP address still shows zeros, replace the formatter.


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NVRAM initialization


Only perform the following procedure if absolutely necessary. Performing an NVRAM


initialization resets some parameters that cannot be restored later.


NVRAM initialization sets all default variables stored in NVRAM back to factory default


values or to a default ROM value, depending on the variable. It also performs a system reset.


NVRAM initialization resets the following:


All menu settings to factory default values


Factory settings such as formatter number, page counts, and factory paper settings


To perform NVRAM initialization



Turn the printer off.



Press and hold down the GO button.



Turn the printer on, and continue to hold the GO button for at least 20 seconds. During



this process, the GO button, Attention, and Ready LEDs each turn on.



Release the GO button.


The printer LEDs will begin cycling. The NVRAM-unitprocess runs until the printer is in the


ready state.

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