Lexmark X543 Service Manual

							Repair information4-7
Lexmark confidential until announce7525xxx
Right cover removal 
1.Remove the media tray.
2.Lift and lock the flatbed assembly to the raised position.
3.Open the front cover.
4.Release the green latches securing the door. 
5.Lower the right cover and remove it from the hinges.
Rear shield removal
The rear shield is not a field replaceable unit (FRU). 
1.Remove the six screws (A).
2.Remove the rear shield.
A 
						

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AIO back cable cover removal
1.Remove the two screws (A) which secure the AIO back cable cover to the MFP.
2.Place a small flat-blade screwdriver under the bottom of the cover, and gently pry the cover upward.
A 
						

							Repair information4-9
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Top cover assembly removal
1.Remove the flatbed assembly. Go to “Flatbed removal” on page 4-53.
2.Remove the AIO toner cover. Go to “AIO toner cover” on page 4-75.
3.Remove the five screws (A) from the left front side.
4.Remove one screw (B) from the top right side of the cover.
A
B 
						

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5.Remove the four screws (C) on the right side of the top cover.
6.Remove one screw (D) from the rear.
C
D 
						

							Repair information4-11
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7.Detach the re-drive belt (E) from the pulley on the fuser exit roll shaft.
8.Disconnect the fan power cable from JFAN1 on the controller board.
9.Disconnect the bin full sensor cable from the controller board.
10.Remove the top cover, being careful to route the fuser exit sensor cable through the top of the controller 
board cage.
Installation
Warning:  Make sure the belt is attached to the gear (B), Also; check the tension spring to make sure it is 
properly attached to the top cover (C). The following illustration shows the properly attached spring 
and belt. 
Warning:  After performing any repair that involves detaching the belt from the re-drive pulley on the fuser, run 
approximately 30 test pages, both simplex and duplex, to ensure the belt is performing properly. 
While the pages are running, listen for any noises, buzzing, clicking or rattling, that might indicate 
improper routing of the re-drive belt. 
E 
						

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Autocompensator mechanism (ACM)—standard tray removal
1.Remove the toner bottles, the waste toner container, and the imaging unit (IU). See “Imaging unit (IU) 
removal” on page 4-28 and see “Waste toner bottle” on page 4-49. 
2.Remove the rear shield. See “Rear shield removal” on page 4-7. 
3.Remove the left cover. See “Left cover removal” on page 4-4.
4.Remove the right cover. See “Right cover removal” on page 4-7.
5.Disconnect the autocompensator mechanism (ACM) cable connector (A) from the controller board. 
6.Unclip the cable (B) from the retainers (C) on the left side.
7.Reinstall the rear shield to protect the controller board. Turn the printer so the bottom is facing you.
Warning:  For models with a wireless antenna, use supports to prevent the antenna from taking the weight 
of the printer.
8.Carefully tilt the printer so the rear shield rests on the table. 
						

							Repair information4-13
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9.Remove the two springs (D).
10.Remove the two screws (E) on the bottom.  
						

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11.On the right side, loosen the screw (F) with a screwdriver, and hold the ACM in place as you use your 
fingers to remove the screw.
12.Move the right side of the ACM out to free the shaft from the hole in the frame.
Note:  Observe the location of the shaft and hole for reinstallation.
13.Remove the ACM.
Installation notes:
1.Place the left side of the ACM in the printer. Make sure the shaft on the left side aligns with the hole in the 
frame.
2.Turn the printer to the proper upright position.
3.Route the cable through the frame and through the cable channel, making sure to clamp the cables into the 
two retainers on the left side.
4.Remove the rear shield, and connect the cable.
5.Replace the rear shield. 
						

							Repair information4-15
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Bin full sensor
1.Remove the flatbed unit. See “Flatbed removal” on page 4-53.
2.Using a small flatblade screwdriver, gently depress the tabs (A) which secure the sensor to the top cover 
assembly.
3.Pull the sensor away from the top cover assembly.
4.Disconnect the sensor from the cable.
A 
						

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Controller board removal
Warning:  Observe all ESD precautions while handling electrostatic-discharge sensitive parts. See “Handling 
ESD-sensitive parts” on page 4-1.
Warning:  When replacing any one of the following components:
Operator panel assembly
Controller board
Replace only one component at a time. Replace the required component, and perform a POR before replacing a 
second component listed above. If this procedure is not followed, the printer will be rendered inoperable. Never 
replace both of the components listed above without a POR after installing each one, or the printer will be 
rendered inoperable.
Warning:Never install and remove components listed above as a method of troubleshooting components. 
Once a component has been installed in a printer, it cannot be used in another printer. It 
must be returned to the manufacturer.
CAUTION - POTENTIAL INJURY: There is danger of explosion if a lithium battery is incorrectly 
replaced. Replace it only with the same or an equivalent type of lithium battery. Do not recharge, disassemble, or 
incinerate a lithium battery. Discard used batteries according to the manufacturers instructions and local 
regulations.
1.Remove the rear shield See “Rear shield removal” on page 4-7.
2.Remove the fax card. See “Fax card removal” on page 4-80.
3.Remove the fax card standoff from the controller board.
4.Disconnect all the cables from the controller board.
5.Remove the six screws (A) that are securing the controller board to the controller board cage.
6.Remove the board.
Installation notes: 
When replacing the rear shield, make sure to route all of the cables through the correct shield opening. 
Make sure that the ground wire that is being held by the front, upper screw is in the correct location before 
installing.
Print a few pages to verify the installation. If the pages are blank, confirm that the high-voltage power 
supply cable is properly seated. The connector may have been loosened at the HVPS.
A