Middle Front Drawer Will not Open, Close or 'Close Middle Front Drawer' Message Will not Clear

Six main issues may prevent the middle front drawer of the HP Color LaserJet 4500 or 4550 series printer from opening or closing correctly:

During the printer's initialization, two lifting cam levers raise the Intermediate Transfer Belt (ITB) towards the imaging drum. (See Figure 1, call-out 2.) If the initialization stage is interrupted for any reason before the printer reaches a READY state, CL2 which engages the ITB, cleaning roller, and locks the drawer, preventing the middle front drawer from being opened.

Severe paper jam (enough to bind the fuser drive train, such as with a transparency jam in the fuser) may also cause this issue. This type of stuck middle front drawer should also result in a whining noise on power up.

If the transfer roller has been installed backwards, the middle front drawer will not open or close completely. You will also hear a loud, whining noise at power up because of binding gears (Figure 1, call-out 1 shows the transfer roller installed correctly).

The transfer roller assembly may be raised. If the initialization or printing stage is interrupted, CL4, which raises the assembly, may stick, preventing the middle front drawer from completely opening or closing.

The middle front drawer latch is broken.

The drawer switch (SW1) remains open when the drawer is closed.

The switch remains open because the lock lever on the left side of the drawer assembly intermittently fails to make contact with the switch. This issue is associated only to HP Color LaserJet 4500 series printers with serial numbers JPHxxxxxxx. Refer to the following service notes for complete information: C4084A-08A, C4089A-08A, and C4094A-08A.

NOTE: Before replacing the drawer, make sure the problem is associated with this assembly. Verify that the drawer will open and close properly (often repeated opening and closing of the drawer will clear the message temporarily.) If the drawer will not open or close properly, the problem is most likely due to another cause.

CAUTION: Educate the customer that unplugging the printer before the printer comes to a READY state or during printing may prevent the middle front drawer from opening or closing. Also, opening drawers during calibration or printing can cause this. Never force the drawer open if it becomes stuck. That can cause more damage.

Figure1: Looking into the printer after removing the middle front drawer1 -Blue gear on the transfer roller on right hand side (if installed correctly) 2 -One of two ITB lifting cam levers

Closing a middle front drawer

Try the following troubleshooting step to close a middle front drawer. In many cases, the two lifting cam levers (Figure 1, call-out 2) are raised, preventing the drawer from shutting.

Turn the printer off.

Unplug the power cord.

Remove the ITB and the middle front drawer.

Plug the power cord in again.

Defeat the two interlock switches inside the middle front drawer area as shown in Figure 2, call-out 1.

Turn the printer on.

During calibration, the lifting cam levers (Figure 2, call-out 2) should reset.

 Figure 2: Interlock switches and lifting cam lever for the middle front drawer 1 -Interlock switches 2 -Lifting cam levers

Opening a stuck middle front drawer

Try the following troubleshooting steps to open a stuck middle front drawer. In many cases, the transfer roller has been installed backwards.

Power off the printer, and close the middle front drawer all the way. Press on the power button, at the same time pull on the drawer to open. Repeat this step several times; if it does not open, continue onto the next step.

Turn the printer off.

Unplug the power cord and remove the HP Jetdirect card if one is installed.

Open the rear door(s) and remove the fuser.

Check fuser for jammed media. Open the paper jam access door on the rear of the fuser, inspect the upper and lower fusing rollers, and ensure they are free from jammed media or defect.

Inspect the area around the feeder assembly and remove any jammed media.

Insert the fuser and close the rear door(s).

Perform a drum test in diagnostics mode to try and reset the ITB unit separation clutch (CL2). To perform a drum test, do the following:

Plug the power cord in again.

Hold down the left side of the ITEM key panel while turning the printer on.

Continue holding down the left side of the ITEM key until Diagnostic Mode appears.

Press the MENU key until Engine Diags Continuous=N appears.

Press the ITEM key until Engine Diags Drum Test appears.

Press SELECT. (The two white clutch assembly gears in Figure 3 will rotate into the correct position.)

Try to open the middle front drawer after the test is completed. If the drawer will not open, turn the printer off and on again. Continue with Step 7.

Wait for the printer to complete its initialization sequence.

If the printer comes to a READY state, try opening the middle front drawer.

If the drawer still does not open, proceed with Step 8.

Remove the left-side cover and CL2 to lower the ITB lifting cam.

The ITB lifting camshaft is not in the home position if the alignment marks on the clutch assembly gears are offset 180 degrees. See Figure 5 for the correct position. Remove the two white clutch assembly gears in front of CL2. See Figure 3.

Figure 3: Looking under the left side cover 1 -Two white clutch assembly gears

The shaft that the right-hand side gear sits on is D shaped. If the ITB lifting camshaft is in the home position, the flat part of the D should be facing up. If not, proceed to Step 10.

Remove CL2.

Return the right-hand side gear onto its shaft. (Leave the left-hand side gear off.)

Manually rotate the shaft counterclockwise until you feel this shaft drop into its home position. See Figure 4; it is difficult to rotate the shaft. Use a cloth to grip the gear more easily.

Figure 4: Rotating the right-hand side gear counterclockwise

The D shaft should now face up.

The middle front drawer should successfully open or close now. If not, proceed with Step 11.

Remove CL4 and rotate the shaft clockwise to lower the transfer roller assembly. See Figure 5.

Figure 5: Rotating the shaft for CL4 clockwise to lower the transfer roller assembly

Reinstall CL4 and both clutch assembly gears if the middle front drawer opens and closes correctly.

NOTE: Make sure the clutch assembly gears are correctly installed. For older printers, the gear alignment marks should be offset by one gear tooth as shown in Figure 6, call-out 1. For newer printers, the gears, which have a double line, should be aligned as shown in Figure 6, call-out 2.

Figure 6: Close-up of the gear alignment marks for an older and new printer 1-Offset gear alignment on an older printer 2-Aligned double line on a newer printer

NOTE: Once you are able to open the middle front drawer, verify that the two ITB lifting cam levers (Figure 1, call-out 2) and the transfer roller are not damaged in any way. If so, replace them accordingly.

The middle front drawer will not open, but the printer functions properly

Follow the troubleshooting steps below:

In some cases, the middle front drawer latch breaks, preventing the drawer from being opened. The printer functions properly, but the drawer cannot be opened. Use the following troubleshooting steps to open the drawer.

Figure 7: Side view of the middle front drawer opened 1-Middle front drawer latch

NOTE: Under normal conditions, the middle front drawer opens when the drawer handle (Figure 9, call-out 1) lowers the drawer latch (Figure 7, call-out 1). If the handle breaks, the latch will not move, preventing the drawer from being opened.

Figure 8: View under the left-side cover 1-Middle front drawer release

Remove the left skin to manually release the middle front drawer latch (Figure 8, call-out 1).

Figure 9: View from the left side of the printer 1-Middle front drawer handle 2-Middle front drawer latch release

Open the middle front drawer by pressing in on the drawer handle with one hand (Figure 9, call-out 1) while pressing in on the latch release with the other hand (Figure 9, call-out 2).

NOTE: Press the latch in towards the drawer cover.

Replace the middle drawer cover.

© 2005 Hewlett-Packard