Lexmark X543 Service Manual

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Toner patch sensor (TPS)—left and right removal
The toner patch sensors are similar, but the left sensor includes an extra cable and sensing device. Remove 
them the same way. 
1.Remove the ITU. See “Image transfer unit (ITU)” on page 4-25.
2.Remove the rear shield. See “Rear shield removal” on page 4-7. 
3.Disconnect the toner density sensor cable from JTDS1 connector (A Right) or JTDS2 connector (A Left) on 
the controller board. If you are removing the left toner density sensor, also disconnect the thermistor from 
JFUSES1 connector (B) on the controller board.
Note:  Observe the routing of the cable for reinstallation. 
4.Remove the two screws (C) securing the sensors.
Note:  Observe the routing of the cable for reinstallation. 
Installation notes
Whether you replace the left or right toner density sensors, be sure to perform the TPS Setup. Enter the 32-digit 
TPS value set at the factory and printed on the barcode on the toner density sensor. 
1.Enter the Diagnostics Menu:
a.Turn off the printer.
b.press and hold   and  .
c.Turn on the printer.
d.Release the buttons when the installed memory and processor speed displays.
2.Select TPS SETUP from Diag Menu, and press Select ().
3.Select Right or Left, and press Select ().
TPS Right 1-16 or TPS Left 1-16 appears above a blinking 0 in the left position.
4.To enter a character or digit:
a.press   to decrease or   to increase the blinking value.
b.Pause for several seconds without pressing any buttons. The blinking value becomes solid. 
If the value is incorrect, use Back ( ) to go back and re-enter the number.
c.Continue until the last value is reached.
d.When the last of the 16 values is entered and becomes solid, TPS Right 17-32 or
TPS Left 17-32 appears. 
						

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e.Continue entering and pausing.
5.After the 32nd number is entered and becomes solid, the number is automatically entered.
If the number is incorrect, Checksum does not match appears, and the original screen appears to re-
enter the value. 
If the number is correct, Saving changes to NVRAM appears.
Tray present sensor removal
1.Turn the printer on the left side.
2.Unclip the tray present sensor (A) from the right lower frame.
3.Disconnect the cable from the controller board.
4.Extract the cable with the sensor attached.
Note:  Notice the routing of the cable for reinstallation. 
						

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USB connector removal
1.Remove the rear shield. See “Rear shield removal” on page 4-7. 
2.Disconnect the USB connector (A) from the controller board.
3.Remove the flatbed assembly. See “Flatbed removal” on page 4-53.
Note:  Do not remove the flatbed covers, or any of the hinges. The flatbed only needs to be removed from 
the print engine.
4.Remove the operator panel from the flatbed assembly.“Operator panel removal” on page 4-76.
5.Remove the CCD ribbon cable cover (A), and route the USB cable out through the cable channel on the 
flatbed unit.
Waste toner bottle
The waste toner bottle is a customer replaceable unit.
1.Open the front cover.
2.Lift the toner cover.
3.Remove the right cover assembly. See “Right cover removal” on page 4-7.
4.press the two tabs (A) to release the waste toner bottle, and remove it.
A 
						

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Wireless network antenna
1.Remove the rear shield. See “Rear shield removal” on page 4-7.
2.Lift to disconnect the wireless card (A) from the controller board.
3.Carefully disconnect the antenna cable (B) from the wireless card at the card.
4.Remove the screw (C) that secures the antenna cover (D) to the frame, and remove the antenna cover and 
antenna. 
						

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5.Straighten the antenna perpendicular to the cover, push against the cover with your fingers, and gently 
squeeze the fastener (E) with needlenose pliers. Slide the antenna cable and cable through the hole in the 
bracket.
6.If the fastener is damaged, remove the fastener by pressing the tabs on each side.
Note:  Take note of the orientation of the fastener. When reinstalling, place the cover upright, bend the 
antenna as it would be positioned, and make sure the antenna can move about 30° in each direction from 
the perpendicular. 
						

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Wireless network card
1.Remove the rear shield. See “Rear shield removal” on page 4-7.
2.Lift to remove the wireless card (A) from the controller board.
3.Carefully disconnect the antenna cable (B) from the wireless card at the card. 
						

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Scanner component removal procedures
Flatbed removal
1.Remove the AIO rear cable cover. See “AIO back cable cover removal” on page 4-8.
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 ADF unit. See “Duplex ADF removal” on page 4-63 or “Simplex ADF removal” on 
page 4-64.
5.Disconnect the CCD cable form JCCD1 on the controller board.
6.Remove the toroids (A) from the CCD cable. The toroids will be reused on the new flatbed unit.
A 
						

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7.Disconnect the ADF cable ground wire (B) from the frame.
8.Disconnect JADF1, and route the cable through the top of the card cage.
9.Disconnect the USB cable from JUSB1, op panel cable from JOPP1, flatbed home sensor cable from 
JHS1, and flatbed motor cable from JFBM1. Route the cables through the right side of the card cage.
10.Disconnect the ground wire (C) connecting the redrive unit to the print engine frame.
B
C 
						

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11.Disconnect the screw (D) connecting the flatbed to the AIO link on the rear of the MFP. 
12.Carefully disconnect the AIO link from the flatbed.
13.Remove the two screws (E) securing the flatbed hinge to the top cover.
14.Remove the two springs (F) between the flatbed and top cover. 
D
FE 
						

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15.Gently push the front flatbed hinge (G) towards the front of the top cover to disengage it from the top cover 
guide Pin.
16.Carefully pull the flatbed unit towards the front of the MFP while using your other hand to route the cables 
through the top cover.
17.Remove the CCD ribbon route cover and homing guide attachment.
18.Disconnect the op panel ground termination from the LVPS.
Note:  This completes the removal of the flatbed assembly from the print engine. The removals for the 
FRUs attached to the flatbed are covered under different removal procedures. In addition to the FRUs, the 
following steps illustrate the additional parts that need to be removed from the old flatbed and transferred to 
the new flatbed.
G