Lexmark X 850 Owners Manual

Diagnostic information2-223
7500-XXX
Spots
Step Check Yes No
1 Check the media condition.
Load new, dry, recommended media.
Re-print the defective image.
Does the error continue?Go to step 2. Problem solved.
2 Check the media transfer route.
Is the media route free of contamination or debris?Go to step 3. Remove debris 
or 
contamination.
3 Check the toner cartridge.
Install a new toner cartridge.
Re-print the defective image.
Is the image density normal?Problem solved. Go to step 4.
4 Check the transfer...

2-224MFP Service Manual 7500-XXX
After image
The ghost appears on the media which, may be the image from the previous page or part of the page 
currently printing.
Step Check Yes No
1 Check the media condition.
Load new, dry, recommended media.
Re-print the defective image.
Does the error continue?Go to step 2. Problem solved.
2 Check the toner cartridge.
Install a new toner cartridge.
Re-print the defective image.
Is the image density normal?Problem solved. Go to step 3.
3 Check the heat roll and the...

Diagnostic information2-225
7500-XXX
Background (fog)
Step Check Yes No
1 Check the media condition.
Load new, dry, recommended media.
Re-print the defective image.
Does the error continue?Go to step 2. Problem solved.
2 Check the media transfer route.
Is the media path free of contamination or debris.Go to step 3. Remove debris 
or 
contamination.
3 Check the toner cartridge.
Install a new toner cartridge.
Re-print the defective image.
Is the image density normal?Problem solved. Go to step 4.
4 Check...

2-226MFP Service Manual 7500-XXX
8 Check the printer engine card assembly.
Replace the printer engine card assembly.
Perform a print test.
Does the error continue?Problem solved. Replace the RIP 
card assembly.
Go to “RIP card 
assembly 
removal” on 
page 4-128. Step Check Yes No 

Diagnostic information2-227
7500-XXX
Skew
The printed image is not paralleled with both sides of the media.
Step Check Yes No
1 Check printer installation placement.
Check the installation surface for irregularities. 
Check for missing printer foot. 
Is the setup surface normal?Go to step 2. Correct the 
installation 
placement.
2 Properly load media into the media tray assembly. 
Properly install the media tray assembly into the printer.
Re-print the defective image. 
Does the error continue?Go to step...

2-228MFP Service Manual 7500-XXX
Media damage
Step Check Yes No
1 Check printer installation placement.
Check the installation surface for irregularities. 
Check for missing printer foot. 
Is the setup surface normal?Go to step 2. Correct the 
installation 
placement.
2 Check the media feed.
Remove the media tray assembly. 
Properly load media in the media tray assembly. 
Properly install the media tray assembly in the printer.
Re-print the defective image. 
Does the error continue?Go to step 3. Problem...

Diagnostic information2-229
7500-XXX
No fuse
Step Check Yes No
1 Check the fuser unit assembly installation.
Check that the levers, on both sides of the fuser unit 
assembly, are pushed down. 
Re-print the defective image. 
Does the error continue?Go to step 2. Problem solved.
2 Check the media condition.
Load new, dry, recommended media.
Re-print the defective image.
Does the error continue?Go to step 3. Problem solved.
3 Check the heat roll and the pressure roll.
Remove the fuser unit assembly....

2-230MFP Service Manual 7500-XXX
7 Check the printer engine card assembly.
Replace the printer engine card assembly.
Perform a print test.
Does the error continue?Problem solved. Replace the RIP 
card assembly.
Go to “RIP card 
assembly 
removal” on 
page 4-128. Step Check Yes No 

Diagnostic aids3-1
7500-XXX
3.  Diagnostic aids
This chapter explains the tests and procedures to identify printer failures and to verify that repairs have 
corrected the problem.
Accessing service menus
Access the following menus to identify problems with the printer and run diagnostic tests.
Diagnostics Menu 1. Turn off the printer.
2. Press and hold the 3 and 6 
buttons simultaneously.
3. Turn on the printer.
4. Release the buttons after 10 
seconds.The Diagnostics Menu group consists of menus,...

3-2MFP Service Manual 7500-XXX
Diagnostics Menus
Entering Diagnostics Menus
1.Turn off the printer.
2.Press and hold the 3 and 6 buttons simultaneously.
3.Turn on the printer.
4.Release the buttons after 10 seconds.
Available tests
Tests appear on the LCD in the order shown:
MOTOR TESTSSee “MOTOR TESTS” on page 3-5.
Finisher Motor Tests
Sub paddle solenoid
Media eject clutch
Stapler unit mtr
Bridge unit drv mtr
Motor (entrance/paddle)
Motor (buffer/transport)
Motor (exit)
Media eject clamp mtr
Media...