Lexmark E 450 Dn Service Manual

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Media level indicator removal
1.
Remove the left side cover. See “Left side cover removal” on page 3-4.
2.Turn the printer onto its top. (Be careful to protect the covers.)
3.Unhook and remove the spring (A).
4.Unhook the link (B) from the indicator level.
A 
						

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5.Rotate the link, and turn it to separate it from the plastic shaft (C). Be careful to not damage the adjacent 
gear.
6.Unsnap the shaft from its pivot, which is attached to the back of the LVPS/HVPS shield (D).
7.Align the link end of the shaft with the opening in the side frame, and remove the shaft and spring anchor 
(E). 
						

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Narrow media sensor removal
1.
Remove the top cover. See “Top cover removal” on page 3-7.
2.Turn the top cover upside down.
3.Remove the ground strap screw (A) and the ground strap.
4.Remove the narrow media sensor. 
						

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Operator panel removal
1.
Open the front cover.
2.Remove the bezel. See “Bezel removal” on page 3-12.
3.Remove the screw (A).
4.Remove the face plate which surrounds the bezel by unlatching the four tabs (B).
5.Close the front cover.
6.Disconnect the cable (C). (The LED operator panel connects the same as the LCD panel as shown.)
7.Unlatch the four latches on the panel cover.
8.Pull the bottom edge out until it slides in a downward motion out of its retainers.
9.Slide the card out from the latches on top.
10.Remove the operator panel.
Warning:  Do not replace the operator panel and the controller card at the same time. Each card contains 
the printer settings. When either of these cards is new, it obtains its settings from the other card. Critical 
factory settings are lost when both are new and replaced at the same time.  
						

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Paper exit guide assembly removal
1.
Remove the rear cover. See “Rear cover removal” on page 3-6.
2.Remove the one screw above the reversing solenoid. See “Top cover removal” on page 3-7.
3.Remove the three screws (A).
4.Lift the back of the top cover (right side in photo) to prevent the gears on the assembly from touching other 
items while removing, especially the fuser mounting bracket.
5.Remove the paper exit guide assembly. 
A 
						

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Paper feed rollers (autocompensator tires) removal 
1.
Remove Tray 1.
2.Open or lower the duplex door.
3.Lower the ACM.
4.Remove the rubber paper feed rollers.
Note:  Remove the tire from the hub. Do not attempt to remove the hub.
5.Pinch the new rubber roller into a tight radius to determine the orientation of the tire relative to the hub. 
Notice the direction of the points on the edge. Those points should be directed in the paper feed direction 
as shown.
6.Make sure the new paper feed rollers are captured between the rims of the plastic hub. 
7.If the orientation is questionable, run Print Quality sheets, and check for skew. 
						

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Paper input and duplex sensor removal
1.
Remove the duplex unit. See “Duplex removal” on page 3-18.
2.Remove screws (A) holding the two sensors.
3.Remove the sensor assembly.
Note:  Be sure to secure cables in retainers when installing the new assembly. The solenoid cable should be 
installed on top of the sensor cables. 
						

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Printhead removal
1.
Remove the top cover. See “Top cover removal” on page 4-7 for more information. 
2.Remove the right side cover. See “Right side cover removal” on page 4-5. 
3.Remove the controller card cover.
4.Disconnect the cables J5 DRV (A), J8 LXK LSU (B), and J15 (C) from the controller card.
Note:  Be sure to remove the toroid before disconnecting the cables. 
5.Remove three screws (D) securing the printhead. 
6.Remove the printhead. 
Reinstallation note: 
•Install the new printhead by lining up the alignment knub with the indicator located at the front right-hand 
screw. 
•Be sure to place the toroid back over the cables.
•Mechanically adjust the printhead, if necessary. See “Printhead assembly mechanical adjustment” on 
page 3-10.
•Electronically adjust the printhead. This is a necessary step. See “Printhead assembly electronic 
adjustment” on page 3-6. 
						

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Reversing solenoid removal
1.
Remove the top cover. See “Top cover removal” on page 4-7.
2.Remove the controller card shield. (Loosen the four screws, and slide.) See “Right side cover removal” 
on page 3-5.
3.Disconnect the cable from J9 (DP REV SOL) on the controller card.
4.Remove the two screws (A).
5.Remove the reversing solenoid.
Toner level sensor removal
1.
Remove Tray 1.
2.Open the front access cover.
3.Open the right side cover.
4.Unplug the toner level sensor cable. 
5.Unsnap the toner level sensor (A) from the frame, and remove it through the inside of the printer. 
A 
						

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Transfer roll removal
Note:  A flashlight may be required to remove the transfer roll.
1.Open the front access cover. 
2.Place a clean piece of paper around the transfer roll to protect it from finger oils. 
Note:  Do not touch the transfer roll with bare hands. Contaminants can damage the roll.
3.At the right side of the transfer roll, squeeze the holder arms with the left hand while lifting. Stop when the 
holder is unlatched. 
4.At the left side of the transfer roll, squeeze the holder arms with the right hand while lifting with the left 
hand. Stop when the left holder is unlatched. 
5.With a hand at each end, lift the transfer roll out. 
Note:  Do not try removing the spring on the left; it is not removeable but can be dislodged. The spring included 
with the FRU is to be used only if the old right-side spring is damaged or lost. Both springs must be positioned 
on posts that cannot be seen. If the old springs are moved, feel the base of the springs to assure that they are on 
the posts. The top of the springs must be captured in the bearings of the transfer roll.