Lexmark X543 Service Manual

Repair information4-7
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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...

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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...

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...

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,...