Lexmark X 850 Owners Manual

Repair information4-93
7500-XXX
18.Slide the PC cartridge guide (D) toward the left side, and disconnect the connector from the PC cartridge 
sensor connector (E). 
19.Remove the two hooks securing the transfer roll power contact (F). 
20.While pressing the PC cartridge drive coupler (G), lift the front side of the PC cartridge guide (C) upward.
21.Disconnect the connector from the sensor (humidity and temperature) (H). 
22.Remove the screw securing the sensor (humidity and temperature) (H) to the PC...

4-94MFP Service Manual 7500-XXX
Sensor (RFID PC cartridge) and sensor (RFID toner cartridge) removal
Note:  This removal applies to the sensor (RFID PC cartridge) (A) and the sensor (RFID toner 
cartridge) (B). 
1.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5.
2.Remove the toner cartridge guide assembly. See “Toner cartridge guide assembly removal” on 
page 4-95.
3.Disconnect the connector from the sensor (RFID PC cartridge) (A) or the sensor (RFID toner cartridge) (B)....

Repair information4-95
7500-XXX
Toner cartridge guide assembly removal
1.Remove the printer front left cover. See “Printer front left cover removal” on page 4-3.
2.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5.
3.Remove the PC cartridge. 
4.Remove the toner cartridge. 
5.Remove the printer front door assembly. See “Printer front door assembly removal” on page 4-6.
6.Remove the front inner cover. See “Front inner cover removal” on page 4-8.
7.Disconnect the two harnesses from...

4-96MFP Service Manual 7500-XXX
13.While moving the toner cartridge guide assembly (A) to the left, release the toner add chute (B) from the 
frame. Remove the toner cartridge guide assembly (C) from the printer.
Note:  Remove all spilled toner from the printer.
Note:  Before reinstalling, ensure the shaft on the toner cartridge guide assembly is inserted into the toner add 
motor assembly (C).
Note:  Before reinstalling, ensure the shaft (C) on the toner cartridge guide assembly (A) is inserted into the...

Repair information4-97
7500-XXX
Toner add motor assembly removal
1.Remove the printer front left cover. See “Printer front left cover removal” on page 4-3.
2.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5.
3.Remove the PC cartridge. 
4.Remove the toner cartridge. 
5.Remove the printer front door assembly. See “Printer front door assembly removal” on page 4-6.
6.Remove the front inner cover. See “Front inner cover removal” on page 4-8.
7.Remove the toner cartridge guide...

4-98MFP Service Manual 7500-XXX
Fuser cooling fan removal
1.Remove the rear RIP card cover. See “Rear RIP card cover removal” on page 4-13.
2.Remove the rear motor cover. See “Rear motor cover removal” on page 4-11.
3.Disconnect the connector from the fuser cooling fan (A) from the dual drive motor assembly (B). 
4.Release the two hooks securing the fuser cooling fan (A) to the fan duct (C). 
5.Remove the fuser cooling fan (A). 
Note:  Before reinstalling, the fuser cooling fan (A) must be installed with...

Repair information4-99
7500-XXX
Printhead assembly removal
1.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5.
2.Open the printer front door assembly. See “Printer front door assembly removal” on page 4-6.
3.Remove the PC cartridge. 
4.Remove the toner cartridge. 
5.Remove the printer front door assembly. See “Printer front door assembly removal” on page 4-6.
6.Remove the front inner cover. See “Front inner cover removal” on page 4-8.
7.Remove the toner cartridge guide...

4-100MFP Service Manual 7500-XXX
PC cartridge cooling fan duct removal
1.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5.
2.Disconnect the harness from the duct connector. 
3.Release the connector harness from the clamp on the PC cartridge cooling fan duct (A). 
4.Release the hook securing the PC cartridge cooling fan duct (A) to the toner cartridge guide assembly (B). 
Hook
B
A
Front
AB
Front viewHook 

Repair information4-101
7500-XXX
5.Move the PC cartridge cooling fan duct (A) in the direction of the arrow while lifting the left side, to release 
the hook securing it to the toner cartridge guide assembly (B).
6.Remove the PC cartridge cooling fan duct (A).
Connector
Hooks
Front A Connector
Holes
Clamps
ConnectorB 

4-102MFP Service Manual 7500-XXX
PC cartridge cooling fan removal
1.Remove the top cover assembly. See “Top cover assembly removal” on page 4-5. 
2.Remove the PC cartridge cooling fan duct. See “PC cartridge cooling fan duct removal” on 
page 4-100. 
3.Disconnect the harness of the PC cartridge cooling fan (A) to the PC cartridge cooling fan duct (B). 
4.Release two hooks securing the PC cartridge cooling fan (A) to the PC cartridge cooling fan duct (B).
Note:  Use care in handling the PC cartridge...