Lexmark X 850 Owners Manual

							Diagnostic information2-203
7500-XXX
Tray 4 media size failure
StepCheckYe sNo
1Check the media. 
Pull out tray 4, and visually check it.
Is the media loaded in tray 4 properly?Go to step 2.Load media 
properly.
2Check the media.
Pull out tray 4, and visually check it.
Are the front media guide and rear media guide on tray 
4 set correctly?Go to step 3.Set the parts 
properly.
3Check the switch (TTM media size) for proper 
installation.
Pull out tray 4, and visually check it. 
Is the switch (TTM media size) for tray 4 installed 
properly?Go to step 4.Install the switch 
(TTM media size) 
correctly.
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.
4Check the switch (TTM media size) for proper 
connection.
Is the above switch connected correctly?Replace the switch 
(TTM media size).
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.Replace the 
connection.
5Check the 2TM/TTM controller card assembly and the 
printer engine card assembly for proper connection.
Are connectors P541 and P413 on the above cards 
connected properly?Go to step 6.Replace the 
connection.
6Perform a print test.
Does the error still occur?Replace the 2TM/
TTM controller card 
assembly. 
Go to “2000-sheet 
dual input (TTM)–
2TM/TTM controller 
card assembly 
removal” on 
page 4-274.
Go to step 7.Problem solved.
7Perform a print test.
Does the error still occur?Replace the printer 
engine card 
assembly.
Go to “Printer 
engine card 
assembly removal” 
on page 4-117.Problem solved. 
						

							2-204MFP Service Manual 7500-XXX
Tr a y 3 media size mismatch in length
StepCheckYe sNo
1Check the media. 
Pull out tray 3, and visually check it.
Is the media loaded in tray 3 properly?Go to step 2.Load media 
properly.
2Check the media. 
Pull out tray 3, and visually check it.
Are the front media guide and rear media guide on 
tray 3 set correctly?Go to step 3.Set the parts 
properly.
3Check the switch (TTM media size) for proper operation.
Pull out tray 3, and visually check it.
Is the switch (TTM media size) for tray 3 installed 
properly?Go to step 4.Install the switch 
(TTM media size) 
correctly.
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.
4Check the switch (TTM media size) for proper 
connection.
Is the above switch connected properly?Replace the switch 
(TTM media size).
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.Replace the 
connection.
5Check the 2TM/TTM controller card assembly and the 
printer engine card assembly for proper connection. 
Are connectors P541 and P413 on the above cards 
connected properly?Go to step 6.Replace the 
connection.
6Check the tray 3 rolls.
Pull out tray 3, and check it.
Are the feed roll, separation roll, and pick roll for 
transport free of excess wear and contamination?Go to step 7.Clean or replace the 
feed roll, separation 
roll, and pick roll.
Go to “2000-sheet 
dual input (TTM)–
feed roll removal” 
on page 4-259, 
“2000-sheet dual 
input (TTM)–
separation roll 
removal” on 
page 4-263, and 
“2000-sheet dual 
input (TTM)–pick 
roll removal” on 
page 4-266.
7Check the media position.
Open the printer left door assembly, and visually check 
it. 
Does the media touch the sensor (registration)?Remove the media.Go to step 8.
8Check the roll. 
Open the printer left door assembly, and visually check 
it.
Is the transport roll assembly for transport free of excess 
wear and contamination?Go to step 9.Clean or replace the 
transport roll 
assembly. 
						

							Diagnostic information2-205
7500-XXX
9Check the roll. 
Open the printer left door assembly, and visually check 
it.
Is the registration roll assembly for transport free of 
excess wear and contamination?Go to step 10.Clean or replace the 
registration roll 
assembly.
Go to “Registration 
roll assembly 
removal” on 
page 4-79.
10Check the sensor (registration) for proper operation.
1. Enter the Diagnostics Menu.
2. Touch BASE SENSOR TEST.
3. Touch Media Path.
4. Touch Registration.
Open the printer left door assembly, and visually check 
it.
Does the display on the operator panel change every 
time the actuator on the above sensor operates?Go to step 12.Go to step 11.
11Check the sensor (registration) for proper connection.
Is the above sensor connected properly?Replace the sensor 
(registration).
Go to “Sensor 
(registration) 
removal” on 
page 4-81. Replace the 
connection.
12Check the registration clutch for proper operation.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Registrat clutch.
Does the above component make an audible clicking 
sound every time it operates?Go to step 14.Go to step 13.
13Check the registration clutch for proper connection.
Is the above component connected properly?Replace the 
registration clutch.
Go to “Registration 
clutch assembly 
removal” on 
page 4-80.Replace the 
connection.
14Perform a print test.
Does the error still occur?Replace the 2TM/
TTM controller card 
assembly. 
Go to “2000-sheet 
dual input (TTM)–
2TM/TTM controller 
card assembly 
removal” on 
page 4-274.
Go to step 15.Problem solved.
15Perform a print test.
Does the error still occur?Replace the printer 
engine card 
assembly.
Go to “Printer 
engine card 
assembly removal” 
on page 4-117.Problem solved.
StepCheckYe sNo 
						

							2-206MFP Service Manual 7500-XXX
Tray 4 media size mismatch in length
StepCheckYe sNo
1Check the media. 
Pull out tray 4, and visually check it.
Is the media loaded in tray 4 properly?Go to step 2.Load media 
properly.
2Check the media. 
Pull out tray 4, and visually check it.
Are the front media guide and rear media guide on 
tray 4 set correctly?Go to step 3.Set the parts 
properly.
3Check the switch (TTM media size) for proper 
installation.
Pull out tray 4, and visually check it.
Is the switch (TTM media size) for tray 4 installed 
properly?Go to step 4.Install the switch 
(TTM media size) 
correctly.
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.
4Check the switch (TTM media size) for proper 
connection.
Is the above switch connected properly?Replace the switch 
(TTM media size).
Go to “2000-sheet 
dual input (TTM)–
switch (TTM media 
size) removal” on 
page 4-242.Replace the 
connection.
5Check the 2TM/TTM controller card assembly and the 
printer engine card assembly for proper connection.
Are connectors P541 and P413 on the above cards 
connected properly?Go to step 9.Replace the 
connection.
6Check the tray 4 rolls.
Pull out tray 4, and check it.
Are the feed roll, separation roll, and pick roll for 
transport free of excess wear and contamination?Go to step 7.Clean or replace the 
feed roll, separation 
roll, and pick roll.
Go to “2000-sheet 
dual input (TTM)–
feed roll removal” 
on page 4-259, 
“2000-sheet dual 
input (TTM)–
separation roll 
removal” on 
page 4-263, and 
“2000-sheet dual 
input (TTM)–pick 
roll removal” on 
page 4-266.
7Check the media position.
Open the printer left door assembly, and visually check 
it. 
Does the media touch the sensor (registration)?Remove the media.Go to step 8. 
						

							Diagnostic information2-207
7500-XXX
8Check the roll. 
Open the printer left door assembly, and visually check 
it.
Is the media transport roll assembly for transport free of 
excess wear and contamination?Go to step 9.Clean or replace the 
media transport roll 
assembly.
Go to “2000-sheet 
dual input (TTM)–
2TM/TTM media 
transport roll 
assembly removal” 
on page 4-246.
9Check the roll. 
Open the printer left door assembly, and visually check 
it.
Is the registration roll assembly for transport free of 
excess wear and contamination?Go to step 10.Clean or replace the 
registration roll 
assembly.
Go to “Registration 
roll assembly 
removal” on 
page 4-79.
10Check the sensor (registration) for proper operation.
1. Enter the Diagnostics Menu.
2. Touch BASE SENSOR TEST.
3. Touch Media Path.
4. Touch Registration.
Open the printer left door assembly, and visually check 
it.
Does the display on the operator panel change every 
time the actuator on the above sensor operates?Go to step 12.Go to step 11.
11Check the sensor (registration) for proper connection.
Is the above sensor connected properly?Replace the sensor 
(registration).
Go to “Sensor 
(registration) 
removal” on 
page 4-81.Replace the 
connection.
12Check the registration clutch for proper operation.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Registrat clutch.
Does the above component make an audible clicking 
sound every time it operates?Go to step 14.Go to step 13.
13Check the registration clutch for proper connection.
Is the above component connected properly?Replace the 
registration clutch.
Go to “Registration 
clutch assembly 
removal” on 
page 4-80.Replace the 
connection. 
14Perform a print test.
Does the error still occur?Replace the 2TM/
TTM controller card 
assembly. 
Go to “2000-sheet 
dual input (TTM)–
2TM/TTM controller 
card assembly 
removal” on 
page 4-274.
Go to step 15.Problem solved.
StepCheckYe sNo 
						

							2-208MFP Service Manual 7500-XXX
Image quality trouble
Troubleshooting
Note:  First, get a printout as a base, and follow the symptom table to identify the possible failing FRU’s. 
Image quality symptoms: 
•
Faint print (low contrast)– “Faint print (Low contrast)” on page 2-209.
•Blank print (no print)– “Blank print (no print)” on page 2-211.
•Solid black– “Solid black” on page 2-213.
•Vertical blank lines (White stripes in media transport direction)– “Vertical blank lines (white stripes in 
media transport direction)” on page 2-214.
•Horizontal band–“Horizontal bands” on page 2-216
•Printhead out– “913.00 Printhead assembly failure” on page 2-155 
•Vertical stripes– “Vertical stripes” on page 2-218.
•Horizontal stripes– “Horizontal stripes” on page 2-220.
•Partial lack– “Partial lack” on page 2-222.
•Spots– “Spots” on page 2-223.
•Afterimage– “After image” on page 2-224.
•Background (fog)– “Background (fog)” on page 2-225. 
•Skew–“Skew” on page 2-227.
•Media damage– “Media damage” on page 2-228.
•No fix–“No fuse” on page 2-229.
Note:  When horizontal lines and/or spots occur periodically, it is possibly caused by a particular roll. In this 
case, measure the interval on the print test, and check the relation to the roll in the printer. The interval does not 
necessarily match circumference of the roll. 
15Perform a print test.
Does the error still occur?Replace the printer 
engine card 
assembly.
Go to “Printer 
engine card 
assembly removal” 
on page 4-117.Problem solved.
StepCheckYe sNo 
						

							Diagnostic information2-209
7500-XXX
Image Quality 
Faint print (Low contrast)
Before starting, check the media route for foreign objects, such as staples, clips, and scraps, in the media path. 
Step Check Yes No
1 Check the media condition.
Load new, dry, recommended media, and perform a print 
test.
Is the image density normal?Problem solved. Go to step 2.
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 transfer roll assembly.
Remove the transfer roll assembly. 
Check the transfer roll assembly for contamination and 
wear.
Is the transfer roll assembly free of excess wear and 
contamination?Go to step 4. Replace the 
transfer roll 
assembly.
4 Check the PC cartridge installation.
Remove the PC cartridge.
Check the PC cartridge connections.
Are the PC cartridge connections free of excess wear 
and contamination?Go to step 5. Correct and 
clean 
contaminated 
pins, or replace 
the PC cartridge 
or connector.
5 Check the drum grounding plate.
Remove the PC cartridge.
Check the drum grounding plate, located behind the rear 
motor cover. This plate can be found behind the flywheel.
Is the drum grounding plate free of excess wear and 
contamination?Go to step 6. Correct and 
clean the drum 
grounding plate, 
or replace the 
PC cartridge.
Leading edge
Trailing edge 
						

							2-210MFP Service Manual 7500-XXX
6 Check the image development process.
Perform a print test. Turn off the printer power while 
printing.
Carefully remove the PC cartridge, and check the 
developed image formed on the drum right before the 
transfer roll assembly. 
Is the image completely formed on the drum, and the 
area clear, black, and easy to read?Go to step 7. Go to step 9.
7 Check the image transfer process.
Check the toner image formed on the drum after the 
transfer roll assembly.
Is the toner image completely transferred on the media?Go to step 9. Go to step 8.
8 Check the HVPS card assembly. 
Replace the HVPS card assembly.
Perform a print test.
Is the trouble rectified?Problem solved. Go to step 9.
9 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 information2-211
7500-XXX
Blank print (no print)
Check the media path for foreign objects such as staples, clips, scraps of media.
Step Check Yes No
1 Check the toner cartridge.
Install a new toner cartridge.
Re-print the defective image.
Is the image density normal?Problem solved. Go to step 2.
2 Check the transfer roll assembly.
Remove the transfer roll assembly.
Check the transfer roll assembly rotation. 
Is the transfer roll assembly free of excess wear and 
contamination?Go to step 3. Replace the 
transfer roll 
assembly.
3 Check the PC cartridge installation condition.
Remove the PC cartridge.
Check the PC cartridge connections.
Are the PC cartridge connections free of excess wear 
and contamination?Go to step 4. Correct and 
clean 
contaminated 
pins, or replace 
the PC cartridge 
or connector.
4 Check the PC cartridge ground.
Remove the PC cartridge.
Check the drum grounding plate, located behind the 
rear motor cover. This plate can be found behind the 
flywheel.
Is the drum grounding plate free of excess wear and 
contamination?Go to step 5. Correct and 
clean the drum 
grounding plate, 
or replace the 
PC cartridge.
5 Check the laser beam route.
Check for debris between the printhead assembly and 
the PC drum.
Check the printhead assembly window for 
contamination.
Is the laser beam route free of debris and the glass 
window, in the printhead assembly, free of 
contamination?Go to step 6.  Remove debris 
or clean the 
printhead 
assembly 
window. 
						

							2-212MFP Service Manual 7500-XXX
6 Check the printhead installation.
Is the printhead assembly installed properly with four 
screws?Go to step 8. Go to step 7.
7 Check the printhead assembly installation. 
Install the printhead assembly properly, and perform a 
print test.
Does the error continue?Problem solved. Go to step 8.
8 Check the printhead for proper connection.
Warning: If too much force is applied to the board when 
checking it, the printhead could become misaligned. Go to step 9. Replace the 
connection.
9 Check the image development process.
Perform a print test. Turn off the printer power while 
printing.
Carefully remove the PC cartridge. Check the toner 
image formed on the drum before the transfer roll 
assembly.
Is the image completely formed on the drum, and the 
area clear, black, and easy to read?Go to step 10. Go to step 11.
10 Check the image transfer process.
Check the toner image formed on the drum, after the 
transfer roll assembly.
Is the toner image completely transferred on the media?Go to step 12. Go to step 11.
11 Check the HVPS card assembly.
Replace the HVPS card assembly.
Perform a print test.
Does the error continue?Problem solved. Go to step 12.
12 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