Lexmark E 450 Dn Service Manual

Repair information4-3
  4512-630
8.Tilt the front cover down, and disconnect it on the left side from the link.
Warning:  Make sure that the link is not bent or pulled out farther than normal. Otherwise, the toner cartridge 
coupler may become dislodged.
9.Remove the front access cover. 

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Left side cover removal
1.
Remove Tray 1.
2.Open the front access cover.
3.Open the rear door. 
4.Remove the screw (A).
5.Unlatch the cover from the latches (B).
6.Position the printer with the left rear corner hanging over the edge of the table.
7.Swing the cover open.
8.Lift the top rear of the cover over the pivot point, and drop the cover away from the printer. 

Repair information4-5
  4512-630
Right side cover removal 
1.
Remove Tray 1.
2.Open the front access cover.
3.Open the rear door.
4.Release the latches (A), and swing the cover open. 
5.Position the printer with the right rear corner hanging over the edge of the table. 
6.Lift the top rear of the cover over the pivot point, and drop the cover away from the printer.  

4-6Lexmark™ E450dn 4512-630  
Rear cover removal
1.
Remove the right side cover. See “Right side cover removal” on page 3-5.
2.Remove the left side cover. See “Left side cover removal” on page 3-4.
3.Remove the two screws (A). 
4.Open the rear cover.
5.Lift the rear cover, unhooking it from the frame at the bottom, and remove.
Note:  In re-installation, check to make sure that the fuser ground cable is routed out of the way and is not 
pinched or damaged. 

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Top cover removal
1.
Remove the right side cover. See “Right side cover removal” on page 4-5.
2.Remove the left side cover. See “Left side cover removal” on page 4-4.
3.Open the rear door.
4.Remove the two screws (A) from the two front corners on the top cover, the two screws (B) from the two 
rear corners on the top cover, and the screw (C) on the left side.
5.Open the front cover.
6.Remove the two screws (D).
7.Remove the controller card cover.
ABBC
D 

4-8Lexmark™ E450dn 4512-630  
8.Disconnect the cable (E) of the narrow media sensor from J10 on the controller card. 
9.Free the cable while noting which top frame opening it goes through.
10.Release the latches (F) on both sides to unhook the top cover. 
11.Lift and remove the top cover. 
Installation note: 
•Be sure to re-route the cable back through the same hole.
•Be sure that the ground strap aligns at screw (C).
•Verify the proper alignment of the top cover with the paper exit guide along the...

Repair information4-9
  4512-630
Auto comp removal
1.
Remove the duplex. See “Duplex removal” on page 3-18.
2.Remove the auto comp clutch. See“Auto comp clutch removal” on page 3-10.
3.Use a spring hook or a small screwdriver to rotate the latch toward the bottom of the printer until it is 
pointing downward.
4.Lay the printer on its top. Be sure to protect it from marring.
5.Raise the auto comp, and unhook the counter balance spring (A). 

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6.Rotate the arm, and pull to remove the auto comp. 
Auto comp clutch removal
1.
Remove the left side cover. See “Left side cover removal” on page 3-4.
2.Remove the main motor drive. See “Main motor drive removal” on page 3-28.
3.Remove the screws (A). 
Note:  Resistance to loosening the screw may have to be applied to the shaft. Use a finger or small screwdriver 
against the coupler behind the clutch.
4.Remove the auto comp clutch.
A 

Repair information4-11
  4512-630
Auto comp drive shaft assembly removal
1.
Remove the auto comp clutch. See “Auto comp clutch removal” on page 3-10.
2.Use a spring hook or a small screwdriver to dislodge the arm of the shaft bushing, and rotate the arm 
counterclockwise as far as it will go.
3.With the bushing aligned with the frame opening for clearance, unsnap the shaft from the ACM.
4.Remove the auto comp drive shaft assembly.
5.Use a screwdriver to align the ACM with the shaft bearing to help in...

4-12Lexmark™ E450dn 4512-630  
Bezel removal
1.
Open the front access cover.
2.Remove the two screws (A).
3.Lift the lower edge of the shield, slide it to the right, and remove.
4.Release the four inner latches (B).
5.Remove the bezel and lens while the door remains open.
A