Lexmark E 450 Dn Service Manual

							Repair information4-23
  4512-630
11.Unlatch the fuser (see (A) and (B) in the second photo below), and remove. 
Reinstallation note: 
•Be sure to reroute the cables back through their retainers.
•If the printer has been moved following the removal of the fuser, verify that the cross shaft behind the fuser 
is in place.
•Place the fuser into the opening, and push levers (A) to open the latches (B). Push the fuser into the final 
position on the release levers. Alternatively, the fuser may be tilted to drop the latches (B) below the shaft 
for the final few millimeters.
•Check to make sure that the ground cable is routed out of the way and will not be pinched or damaged by 
the rear cover. 
						

							4-24Lexmark™ E450dn 4512-630  
Fuser power cable removal 
1.
Remove the paper exit guide assembly. See “Paper exit guide assembly removal” on page 3-37.
2.Remove the fuser. See “Fuser removal” on page 3-22.
3.Disconnect the power cable from the fuser, and pull the cable through the opening in the side frame.
4.Place the printer on its top with the back and bottom in view.
Note:  Be careful not to mar the finish of the printer.
5.Remove the four screws (A), the machine screw (flange head) (B), and the machine screw (button head) 
(C).
6.Use the hook end of a spring hook to disconnect the fuser power cable from the LVPS/HVPS side.
Note:  The connector latch (D) is toward the side frame as shown. 
						

							Repair information4-25
  4512-630
Link developer drive and access door removal
1.
Remove the main motor drive. See “Main motor drive removal” on page 3-28.
2.Remove the coupling assembly. See “Developer drive coupling assembly removal” on page 3-16.
3.Disconnect the front access door from its hinges. See “Front access cover removal” on page 3-2.
Note:  The cover does not need to be electrically disconnected.
4.
5.
Disconnect the link and door.
6.Remove the developer link. 
						

							4-26Lexmark™ E450dn 4512-630  
LVPS/HVPS card assembly removal
1.
 Remove the rear cover. See “Rear cover removal” on page 4-6.
2.Place the printer onto its top with the back and bottom in view.
Note:  Be careful not to mar the finish of the printer.
3.Remove the four screws (A), the machine screw (B) and the machine screw (C).
4.Unhook the red cable (D) located in the left side frame.
5.Lift the metal cover so the connecting cables (E) and (F) can be unplugged on the side shown.  
						

							Repair information4-27
  4512-630
6.Rotate the assembly, and unplug the remaining cables. 
7.Remove the assembly.
Re-installation note: 
When re-installing the LVPS/HVPS assembly:
•Be sure to locate the rear flange of the card bracket inside of the shield prior to rotating the card assembly 
into final position.
•It is easy for the cables to become pinched during re-installation. Make sure that the cables are free during 
re-installation. 
CAUTION: Make sure that the mylar card is located inside the overlapping 
flanges to avoid damage to the printer. 
						

							4-28Lexmark™ E450dn 4512-630  
Main motor drive removal
1.
Open the left side cover. See “Left side cover removal” on page 4-4 for more information.
2.Tilt the printer onto its right side, and remove the six screws (A), the screw (B), and the ground cable screw 
(C).
IMPORTANT: The ground strap (held by screw B) is not included in the main motor drive FRU. Be sure to 
remove this strap, and install it in the new drive.
3.Lift the motor end, and disconnect the main motor cable (D).
4.Lift the gear assembly, and remove the developer drive spring (E).
ABCD 
						

							Repair information4-29
  4512-630
5.Rotate the motor drive counterclockwise until the two plastic links can be separated. 
6.Remove the main motor drive. 
						

							4-30Lexmark™ E450dn 4512-630  
Manual feed sensor removal
1.
Remove the right side cover. See “Right side cover removal” on page 3-5.
2.Remove the controller card cover by loosening the four screws and sliding the cover free from the screws.
3.Disconnect the sensor from J20 (MPF SNS) on the controller card, and free it back through the opening of 
the side frame.
4.Place the machine on its top.
Note:  Be careful not to mar the finish of the printer.
5.Lift the door on the duplex and auto comp.
6.Remove the screw (A).
7.Free the cable from its retainer, and pull it through the opening toward the sensor mount. 
Re-installation note: 
•Insert the hook end of the spring hook through the frame opening from the controller card side. Extend the 
hook until the sensor connector can be hooked.
•Hook the spring hook to the connector, and pull it through the opening.
•Place the sensor into position, and reconnect the cable on the controller card.
•Using the spring hook, be sure to reroute the cable through the three retainers between the sensor and 
side frame. 
						

							Repair information4-31
  4512-630
Manual paper feed clutch
1.
Open the left side cover. See “Left side cover removal” on page 4-4 for more information.
2.Tilt the printer onto its right side, and remove the six screws (A), the screw (B), and the ground cable screw 
(C).
3.Lift the motor end, and disconnect the main motor cable (D).
4.Lift the main motor drive enough to clear.
Note:  The main motor drive does not have to be completely removed. See “Main motor drive removal” on 
page 3-28 for more information.
5.Use a thin screw driver to remove the clip (E).
6.Remove the manual paper feed clutch.
ABCD 
						

							4-32Lexmark™ E450dn 4512-630  
Manual feed solenoids
1.
Remove the duplex unit. See “Duplex removal” on page 3-18.
2.Extract the solenoid cable to a point close to the left side as possible.
3.Remove the main motor drive. See “Main motor drive removal” on page 3-28.
4.Remove the auto comp clutch. See “Auto comp clutch removal” on page 3-10.
5.Remove the three screws (A).
6.Remove the manual feed solenoids.