Lexmark X543 Service Manual

Repair information4-27
Lexmark confidential until announce7525xxx
8.Rotate the release lever (C) in a counter clockwise direction with a spring hook to decouple the ITU while 
pulling the ITU toward the front.
9.Hold the release lever while removing the ITU.
Installation note:
Write down the 16-digit numeric value of the new FRU before you begin to install it.
You may have to rotate the release lever again to install the new ITU.
When you have replaced the ITU, be sure to enter the 16-digit numeric value...

4-28Service Manual 7525xxxLexmark confidential until announce
Imaging unit (IU) removal
The Imaging unit is customer-replaceable unit and is not a FRU. 
1.Open the front cover.
2.Lift the toner cover by sliding the latch to the left.
3.Remove the waste toner bottle. See “Waste toner bottle” on page 4-49.
4.Remove the cartridge bottles.
5.Lift the two latches (A) to unlock the imaging uni. 

Repair information4-29
Lexmark confidential until announce7525xxx
6.Press and hold the release lever (B), and pull the imaging unit straight out. 

4-30Service Manual 7525xxxLexmark confidential until announce
Developer unit removal
The developer units are not FRUs.
1.Raise the scanner unit, and remove the toner cartridges.
2.Remove the imaging unit. See “Imaging unit (IU) removal”. 
Warning:  Do not touch the underside of the imaging unit. This could damage the developer units.
3.Remove the developer unit you need. 

Repair information4-31
Lexmark confidential until announce7525xxx
Low-voltage power supply (LVPS) assembly
1.Remove the left cover. See “Left cover removal” on page 4-4. 
2.Disconnect the three cables (A) from the LVPS.
3.Remove the six screws (B).
4.Remove the LVPS.  

4-32Service Manual 7525xxxLexmark confidential until announce
Warning:If you receive a new low-voltage power supply with a voltage selector switch (C), be sure to set the 
switch to the correct setting for your voltage requirements before installing the low-voltage power 
supply. The switch can be set for either 115 V or 230 V. Failure to do so will result in damage to the 
power supply.
Note:  Some LVPS FRUs are auto-sensing and do not have the switch, even though the opening may still be 
present in...

Repair information4-33
Lexmark confidential until announce7525xxx
Lower frame removal, right and left
The right and left lower frames are in the same FRU.
Left lower frame
1.
Open the front cover.
2.Remove the waste toner bottle. See “Waste toner bottle” on page 4-49.
3.Remove the imaging unit. See “Imaging unit (IU) removal” on page 4-28.
4.Remove the low-voltage power supply. See “Low-voltage power supply (LVPS) assembly” on 
page 4-31.
5.Place the printer on the right side.
6.Remove the tray 2...

4-34Service Manual 7525xxxLexmark confidential until announce
8.Remove the AC receptacle from the left lower frame.
9.Remove the three screws (D) securing the left lower frame.
10.Remove the screw (E) on top of the frame. 

Repair information4-35
Lexmark confidential until announce7525xxx
11.Swing the left lower frame away from the printer, and remove.
Right lower frame
1.
Open the front cover.
2.Remove the right cover assembly. See “Right cover removal” on page 4-7.
3.Remove the waste toner bottle. See “Waste toner bottle” on page 4-49.
4.Remove the imaging unit. See “Imaging unit (IU) removal” on page 4-28.
5.Remove the rear shield. See “Rear shield removal” on page 4-7.
6.Remove the rear screw (A) in the waste toner...

4-36Service Manual 7525xxxLexmark confidential until announce
8.Carefully place the printer on its left side.
9.Remove the screw (C) securing the wireless antenna (Wireless models only) to access the right frame. Do 
not remove the antenna.
10.Remove the three screws (D) securing the lower right frame to the printer.
11.Remove the screw from the rear of the printer (E).