Lexmark E 450 Dn Service Manual

Repair information4-43
  4512-630
Tray 2 auto comp tire removal
Gently pull the rubber tire loose from the wheel, and replace it with a new tire.
Note:  Look at the nap of the tire, and orient the tire for highest friction when picking the paper. 

4-44Lexmark™ E450dn 4512-630  
Upper front frame group removal
1.
Open the front cover.
2.Unhook the front end of the springs (A) on the right and left sides of the upper frame.
3.Insert the flat end of the spring hook through the front corner opening (B).
4.Push out on the latch by moving the top of the spring hook to the right and while lifting the corner.
5.Repeat for the right side, and remove the assembly.
6.Unlatch the left and right sides of the front cover guide (C) with a flat blade screwdriver...

Repair information4-45
  4512-630
Installation note: Move the printer so the front hangs over the front edge of the work surface. Anchor the left 
spring on its rear post and maintain tension on it while snapping the assembly into position on the left side. Use 
the spring hook from below the printer to anchor the front of the spring. 
Carefully position the unsnapped right side so the right spring can be anchored at the rear. While maintaining 
tension on the spring, snap the right side into position....

4-46Lexmark™ E450dn 4512-630  
Wear strip removal (tray 1)
1.
Hold the tray with the bottom up.
2.Use a spring hook to unfasten each of the anchors on the back of each strip.
3.Remove the strip from inside the tray.
Wear strip removal (tray 2)
1.
Pull up the strip with the spring hook to free it at the top.
2.Lift the strip out. 

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  4512-630
Note: When replacing the strip:
•Push the strip up with your thumb to make sure that the strip is in place.
•Turn the tray over so that you are looking at the bottom of the strip. Using the spring hook, check to make 
sure that the end of the strip is secure and the strip is fastened tightly. 

4-48Lexmark™ E450dn 4512-630   

Locations and connections5-1
4512-630
5. Locations and connections
Locations
Front view
Rear view
150-Sheet
output bin
250-Sheet
tray
550-Sheet drawer
(optional) Paper
support
Control
panel
Front
door
Manual
feeder 

5-2Service Manual 4512-630
Controller card connector pin values
Note:  See the wiring diagram at back of book.
These values were measured with all connections made (plugged) or with only one connector at a time 
unplugged to expose the pins. Always disconnect and connect with the printer power off. Otherwise, the values 
below may not match.
Connector Pin # Value 
cablepluggedVa l ue
cable unplugged
(if different)Comments
J1 1 Signal Smart chip
2Ground
J2 1 Less than 5 V dc Toner level sensor
2Ground
3...

Locations and connections5-3
4512-630
J15 1 5 V dc LSU (HSYNC)
2, 3 Signal
4Ground
J17 1-4 Signal 3.2 V dc Main motor
5Ground
65Vdc
7-9 24 V dc Less than 24 V dc
J19 1-6 Signal LVPS/HVPS
7Ground
8, 9 24 V dc
10, 11, 15 Signal
12, 14 Ground
13 5 V dc
J20 1 Less than 5 V dc 5 V dc Manual feed sensor
25Vdc5Vdc
3Ground
J21 1-4 24 V dc Manual feed solenoids
1, 3 24 V dc
2, 4 0 V dc
J22 1, 4, 5 Signal Tray 2
2, 3 24 V dc
6Ground
J25 1 Less than 5 V dc 5 V dc Paper feed and duplex sensors
25Vdc5Vdc
4 Less than...

5-4Service Manual 4512-630
Connectors
System board
Connector Pin no. Signal
J1 USB Port G1 Ground
1 USB +5 V dc
2 USB D-
3 USB D+
4 Ground
G2 Ground