Lexmark X543 Service Manual

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Lexmark confidential until announce7525xxx
Duplex sensor removal 
1.Open the toner supply cover.
2.Open the front cover.
3.Remove the right cover. See “Right cover removal” on page 4-7. 
4.Remove the waste toner container. See “Waste toner bottle” on page 4-49. 
5.Remove the two screws (A) from the cable channel cover. 
						

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6.Pull the corner of the cable channel cover (B) away from the right side to access the sensor posts (C). 
Unclip the sensor.
7.Remove the sensor, and disconnect the cable (D) from the duplex sensor.
Note:  Close the front cover, and slightly lift the front of the printer to get better access. 
						

							Repair information4-19
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Fuser assembly removal
1.Remove the right cover. See “Right cover removal” on page 4-7.
2.Remove the left cover. See “Left cover removal” on page 4-4.
3.Disconnect the two-wire fuser cable (A) from the LVPS.
4.Position the fuser cable so that it can be pulled through from the front of the printer, and guide the cable to 
the front.
Warning:  Be careful not to damage the cable by pulling too hard or cutting the cable insulation
5.Remove the screw (B) on the right side of the frame.
6.Disconnect the thermistor cable (C) from the fuser. 
						

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7.Unhook the springs (D) from either side of the fuser.
8.Detach the geared belt (E) from the drive pulley on the fuser exit roll shaft.
Note:  Do not remove the pulley or spacer from the shaft.
9.Rotate the top of the fuser toward the front, slide it to the left to align the fuser side frame with the flat areas 
of the shaft (F) and lift to remove the fuser.
Warning:  Be careful to not interfere with or damage the fuser exit sensor to the left of the fuser.
E
F 
						

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Installation notes:
Make sure the springs are resting on the top so they can be reached once the fuser is in place.
When reinstalling on the right, make sure the gears mesh.
Be careful not to interfere with the exit sensor on the left side.
Reroute the cables back through their retainers. 
						

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Fuser drive motor assembly removal
1.Open the front cover. 
2.Remove the right cover. See “Right cover removal” on page 4-7.
3.Disconnect the cable (A) from the fuser drive motor assembly.
Note:  If you remove the toroid (B) from the cable, be sure to return the toroid to the cable when you re-
install.
4.Remove the two screws (C).
5.Remove the fuser drive motor assembly. 
						

							Repair information4-23
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Fuser exit sensor removal
1.Open the front cover. 
2.Remove the fuser assembly. See “Fuser assembly removal” on page 4-19.
3.Remove the screw (A) securing the fuser exit sensor.
4.Disconnect the cable (B) from the fuser exit sensor.
5.Remove the lower end of the sensor with a flat blade screwdriver, and gently pull the sensor from the 
bracket.
6.Remove the sensor. 
						

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High-voltage power supply (HVPS) assembly removal
Note:  This removal requires a magnetized, short-handled Phillips head screwdriver.
1.Remove the top cover assembly. See “Top cover assembly removal” on page 4-9.
2.Remove the rear shield. See “Rear shield removal” on page 4-7.
3.Remove controller board. See “Controller board removal” on page 4-16.
4.Remove the cable cover (A).
5.Disconnect the high-voltage power supply (HVPS) cable at the HVPS.
6.Remove the screw (B). The screw is accessible from the top of the printer, and requires a long-shank 
magnetized Phillips screwdriver. It is the only screw without a flanged head.
7.Remove the screw (C) securing the HVPS. 
						

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8.Carefully slide the HVPS out.
Installation notes: 
When replacing the HVPS, loosely replace screw (C), replace (tighten) screw (B), and tighten screw (C). Also 
make sure that the HVPS cable is securely connected to the controller board and the HVPS unit.
Image transfer unit (ITU)
1.Write down the number on the new ITU before installing it. You will need the 16-digit numeric value from 
the barcode after the installation, and it is easier to see at this point.
2.Remove the right cover. See “Right cover removal” on page 4-7.
3.Remove the rear shield. See “Rear shield removal” on page 4-7. 
4.Remove the waste toner container. See “Waste toner bottle” on page 4-49. 
5.Remove the imaging unit (IU). See “Imaging unit (IU) removal” on page 4-28.  
						

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6.Disconnect the two springs (A) from the side frames, leaving them attached to the ITU at the moment.
7.Rotate the left spring (B) and pivot the cam away from the ITU so the spring is held out of the ITU path.