Close Top Cover Error Message

The toner access cover switch (SW2) indicates whether or not the toner access cover is closed. When the toner access cover is closed, a lever is pushed down. This rotates a pivot forward, closing SW2.

Follow the troubleshooting steps listed below to isolate the cause:

Verify that the toner access cover closes and locks into position.

If the toner access cover does not stay closed, make sure the square, plastic loops and the plastic tab on the door are not broken (see Figure 1, call-outs 1 and 2). If the parts are broken, replace the toner access cover.

Figure 1: Square, plastic loops on the toner access cover 1-Plastic tab 2-Square, plastic loops

Check that black, plastic interlock is seated correctly and not broken.

Remove the top cover.

Make sure that the black plastic interlock the toner access door pushes on is seated correctly in its holder (see Figure 3, call-out 3).

Push down on the interlock to verify the mechanical movement for SW2 and SW5.

NOTE: If the interlock is broken or out of position, replace it by ordering the door switch assembly. A modification has been made to the newer door switch assemblies to guard against the interlock detaching from the assembly.

Verify that the top cover latch assembly on the RFI shield moves freely towards the right side of the printer, then springs back into place.

Manually slide the black, plastic interlock assembly to the right as shown in Figure 2. (The yellow arrows indicate the proper movement). If the assembly does not return to the home position, remove the RFI shield and verify that the spring on the underside of the RFI shield is intact (see Figure 2, call-out 1 for the location of the spring).

Figure 2: Looking down at the top cover latch assembly (highlighted in yellow) on the RFI shield with the location of the spring also highlighted 1-Location of the spring underneath the RFI shield

Check the mechanical movements and electrical connections with SW2 and SW5 (top cover/rear door interrupt switch).

After removing the RFI shield, reseat the connection on SW2 (see Figure 3, call-out 1).

Make sure the connector J1003 on the DC controller PCB is firmly seated.

Figure 3: Side view of SW2, SW5, and the black, plastic interlock

3- SW2

1- SW5

2- Black, plastic interlock

Check the status of SW2 and SW5 in Diagnostics Mode.

To open Diagnostics mode, hold down the left side of the ITEM key and turn the printer ON. The Control Panel will read Diagnostics Mode.

Press ITEM until Engine Diags Door Sensors appears on the front panel.

Press SELECT to activate the test.

The front panel will display A through F with a binary value below it. With the top cover removed, the binary value for A and C should be "1". The identifier A is for SW5 and C is for SW2.

Check the status of A and C during the door sensor test. With the top cover removed, both A and C should show "1."

Press down on the black plastic clip (see Figure 3, call-out 3).

The binary status for C should change from one to zero.

Press in on the metal arm on SW5 (the metal arm presses in on the red button on SW5).

The binary status for A should change from one to zero.

If A changes to zero, but not C, then SW2 is malfunctioning.

If C changes to zero, but not A, then SW5 is malfunctioning.

If either switch is malfunctioning, replace the door switch assembly.

Removal and replacement procedures

Removal and replacement of the top cover

Figure 4: Removing the two screws from the rear of the top cover.

Replacement tip: When replacing the top cover, be sure to properly seat the two plastic retaining tabs on the front of the cover. Firmly seat the top cover.

1. Open the drum drawer (top drawer) until it clears the top cover, then remove the imaging drum, protecting it from the light.

Caution: Exposure to light for more than 15 seconds can seriously damage the imaging drum.

2. Push the release button on the left side of the printer and open the top cover.

3. Open the rear door(s) of the printer.

4. Remove the air filter.

5. Remove the two screws from the top cover. See Figure 4.

6. Lift up on the rear corners of the top cover to release the plastic retaining tabs from the side cover.

7. Rotate the back of the cover toward the left side of the printer, then lift to remove it.

Removal and replacement of the left cover

Figure 5: Removing the left-side cover. 1-Two screws 2-Two tabs located behind the cover

1. Open the drum drawer (top drawer) until it clears the top cover, and then remove the imaging drum, protecting it from the light. 2. Remove the top cover. 3 Open the ITB drawer (middle drawer) and Tray 2. 4. Remove the two screws as shown in call-out 1 of Figure 5. 5. Carefully pull out the bottom of the left cover, disengage the two tabs located behind the cover (see Figure 5, call-out 2), then lift the cover up and off.

Removal and replacement of the RFI shield

Figure 6: Looking down at the RFI shield with the 13 screws highlighted.

1. Turn the printer off, wait five seconds, then unplug the printer.

2. Remove the top cover.

3. Remove the left-side cover.

4. Remove the 13 screws as shown in Figure 6.

5. Lift up on the RFI shield and remove it.

Removal and replacement of the top cover switch and door switch assembly

Figure 7: Removing and replacing top cover switch, door switch assembly

1. Turn the printer off, wait five seconds, then unplug the printer.

2. Remove the top cover.

3. Remove the left-side cover.

4. Remove the RFI shield.

5. Disconnect the sensor and switch cables from the top cover switch assembly. See Figure 7, call-out 1.

6. Follow the instructions below, depending on the version of printer being serviced:

For HP Color LaserJet 4500 printers with serial numbers XXG or lower:

1. Free the sensor and switch cables from their cable stays.

2. Remove the two screws from the top cover switch assembly. See Figure 7, call-out 2.

3. Slide the switch assembly to the left side of the printer, and lift it up and out.

For HP Color LaserJet 4500 printers with serial numbers XXH or higher and CLJ4550 printers:

1. Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it from light.

2. Free the cables from the five cable stays. See Figure 7, call-out 3.

Figure 8: HP Color LaserJet 4500 printers with serial numbers XXH or higher and HP Color LaserJet 4550 printers 1-Two screws on the switch assembly

3. Remove the two screws that secure the switch assembly and lower cable guide to the printer frame. See Figure 8, call-out 1.

4. Pull the rear door switch arm toward the front of the printer while lifting the switch assembly up and out slightly, taking care not to damage the cable guide.

5. Release the five plastic retaining clips securing the switch assembly to the lower cable guide to remove the switch assembly.

Replacement tip: When replacing this assembly, make sure the cable is lying flat in the cable guide. Secure the two tabs on the right side of the switch assembly/cable guide before snapping the three tabs in place on the left side of the assembly.

© 2005 Hewlett-Packard