Lexmark X 850 Owners Manual

							Diagnostic information2-153
7500-XXX
910.00 Transport motor stop failure
2 Turn the printer off for 60 seconds.
Does the error occur when the power is turned off/on again?Replace the 
printer engine card 
assembly. 
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the dual drive motor assembly installation.
Is the dual drive motor assembly properly installed? 
Open the rear motor cover and check it.Go to step 2. Install the PC 
cartridge properly.
2 Check the dual drive motor assembly rotation operation.
Open the rear motor cover and check it.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Transport motor.
Does the motor rotate normally?Go to step 4 Go to step 3.
3 Check the dual drive motor assembly connection.
Is the dual drive motor assembly properly connected?Replace the dual 
drive motor 
assembly.
Go to “Dual drive 
motor assembly 
removal” on 
page 4-113.Replace the 
connection.
4 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved. Step Check Yes No 
						

							2-154MFP Service Manual 7500-XXX
911.00 Transport motor failure
912.00 PC cartridge unit motor failure
Step Check Yes No
1 Check the dual drive motor assembly for operation. 
Open the rear motor cover and check it.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Transport motor.
Does the motor rotate normally?Go to step 3 Go to step 2.
2 Check the dual drive motor assembly for proper installation.
Remove the rear motor cover and check it.
Is the dual drive motor assembly installed properly?Go to step 3. Install the dual 
drive motor 
assembly properly.
3 Check the rotation of the rotor in the dual drive motor 
assembly. 
Open the rear motor cover and check it.
Can the rotor be rotated by hand without excessive load?Go to step 4. Install the dual 
drive motor 
assembly properly.
4 Check the dual drive motor assembly connection.
Is the dual drive motor assembly properly connected? Replace the dual 
drive motor 
assembly.
Go to “Dual drive 
motor assembly 
removal” on 
page 4-113.Replace the 
connection.
5 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the PC cartridge for proper installation.
Is the PC cartridge installed properly?Go to step 2. Install the PC 
cartridge properly.
2 Check the dual drive motor assembly for operation.
Open the rear motor cover and check it.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Drum unit motor.
Does the motor rotate normally.Go to step 4 Go to step 3. 
						

							Diagnostic information2-155
7500-XXX
913.00 Printhead assembly failure
914.00 Toner add motor assembly failure
3 Check the dual drive motor assembly for proper installation.
Open the rear motor cover and check it.
Is the dual drive motor assembly installed properly?Go to step 4. Install the dual 
drive motor 
assembly properly.
4 Check the rotation of the rotor in the dual drive motor 
assembly.
Open the rear motor cover and check it.
Can the rotor be rotated by hand without excessive load?Go to step 5. Install the dual 
drive motor 
assembly properly.
5 Check the dual drive motor assembly connection.
Is the dual drive motor assembly properly connected? Replace the dual 
drive motor 
assembly. 
Go to “Dual drive 
motor assembly 
removal” on 
page 4-113.Replace the 
connection.
6 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the printhead assembly for proper installation.
Is the printhead assembly installed properly?Go to step 2. Install the 
printhead 
assembly properly.
2 Check the printhead assembly connection.
Is the printhead assembly properly connected? Replace the 
printhead. Replace the 
connection.
3 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the toner cartridge for proper installation.
Remove the toner cartridge and reinstall it. 
Does it operate properly?Problem solved. Go to step 2. Step Check Yes No 
						

							2-156MFP Service Manual 7500-XXX
915.00 Fuser cooling fan failure
2 Check the gear rotation for the toner cartridge guide 
assembly.
Remove the toner guide assembly.
Does the gear, located at the lower part of the toner 
cartridge guide assembly, rotate smoothly?Go to step 3. Replace the toner 
cartridge guide 
assembly.
3 Check the toner cartridge guide assembly for pipe clogging.
Is the pipe, located at the lower part of the toner cartridge 
guide assembly, clogged?Go to step 4. Clean the pipe.
4 Check the toner add motor assembly for operation.
Warning: Only perform this test in segments of three 
seconds or less, or toner spill will occur.
Remove the top cover assembly. Go to “Top cover 
assembly removal” on page 4-5.
Override the switch (printer front door interlock)
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Toner add motor.
Observe the toner add motor for rotation. 
Note: When performing this test, the drum unit motor will 
also operate.
Does the motor rotate normally?Go to step 6. Go to step 5.
5 Check the toner add motor assembly connection.
Is the toner add motor assembly properly connected? Replace the toner 
add motor.
“Toner cartridge 
guide assembly 
removal” on 
page 4-95Replace the 
connection.
6 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the fuser cooling fan for proper installation.
Is the fuser cooling fan installed properly?Go to step 2. Install the fuser 
cooling fan 
properly.
2 Visually check the fuser cooling fan for rotation.
Is the fuser cooling fan visually rotating?Go to step 5. Go to step 3. Step Check Yes No 
						

							Diagnostic information2-157
7500-XXX
916.00 PC cartridge cooling fan failure
3 Check the fuser cooling fan for operation.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Fuser cooling fan.
Does the fuser cooling fan RPM increase?Go to step 5. Go to step 4.
4 Check the fuser cooling fan for connection.
Is CN102 on the dual drive motor assembly connected 
properly?Replace the fuser 
cooling fan. Replace the 
connection.
5 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Visually check the PC cartridge cooling fan rotation.
Is the PC cartridge cooling fan visually rotating?Go to step 3. Go to step 2.
2 Check the PC cartridge cooling fan.
Is there an object blocking the PC cartridge cooling fan 
rotation?Remove the object 
blocking the 
rotation.Go to step 3.
3 Check the PC cartridge cooling fan for operation.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch PC unit cooling fan.
Does the fan rotate normally?Go to step 5. Go to step 4.
4 Check the PC cartridge cooling fan connection.
Is the PC cartridge cooling fan properly connected?Replace the PC 
cartridge cooling 
fan. 
Go to “PC 
cartridge cooling 
fan removal” on 
page 4-102.Replace the 
connection.
5 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved. Step Check Yes No 
						

							2-158MFP Service Manual 7500-XXX
917.00 LVPS cooling fan failure
918.00 Sensor (exit 1 media shift HP) failure
Step Check Yes No
1 Check the LVPS cooling fan for proper installation.
Is the LVPS cooling fan installed properly?Go to step 2. Install the LVPS 
cooling fan 
properly.
2 Visually check the LVPS cooling fan for rotation.
Is the LVPS cooling fan visually rotating?Go to step 3. Go to step 4.
3 Check the LVPS cooling fan connection.
Is the LVPS cooling fan connected properly?Replace the LVPS 
cooling fan. 
Go to “LVPS 
cooling fan 
removal” on 
page 4-121.Replace the 
connection.
4 Perform a print test.
Does the error remains?Replace the LVPS 
card assembly.
Go to “LVPS card 
assembly 
removal” on 
page 4-119.Problem solved.
Step Check Yes No
1 Check the sensor (exit 1 media shift HP) for operation.
1. Enter the Diagnostics Menu.
2. Touch BASE SENSOR TEST.
3. Touch Media Path.
4. Touch Exit1 shift HP.
Move the shift assembly, with your finger, in a side to side 
motion. 
Does the display, on the operator panel, change every time 
the sensing area is blocked?Go to step 3. Go to step 2.
2 Check the sensor (exit 1 media shift HP) for connection.
Is the sensor (exit 1 media shift HP) connected?Replace the 
sensor (exit 1 
media shift HP).
Go to “Exit 1 
media shift 
assembly 
removal” on 
page 4-105.Replace the 
connection.
3 Check the media shift motor for operation.
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Exit1 shift motor.
Note: A continuous operation check is allowed up to twice 
for each direction.
Does the motor operate normally?Go to step 5. Go to step 4. 
						

							Diagnostic information2-159
7500-XXX
919.00 Sensor (exit 2 media shift HP) failure
4 Check the media shift motor for connection.
Is the above motor connected properly?Replace the media 
exit shift motor. 
Go to “Media 
shift motor 
removal” on 
page 4-107.Replace the 
connection.
5 Check the printer engine card assembly for connection 
P421 and the exit interface card assembly connector P431.
Are the above cards connected properly?Replace the exit 
interface card 
assembly.
Go to “Exit 
interface card 
assembly 
removal” on 
page 4-116.Replace the 
connection.
6 Perform 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
1Check the sensor (exit 2 media shift HP) for proper 
operation. 
1. Enter the Diagnostics Menu.
2. Touch BASE SENSOR TEST.
3. Touch Media Path.
4. Touch Exit2 shift HP.
Move the shift assembly with your finger in a side to 
side motion.
Does the display on the operator panel change every 
time the sensing area of the above sensor is blocked?Go to step 3.Go to step 2.
2Check the sensor (exit 2 media shift HP) for proper 
connection.
Is the above sensor connected properly?Replace the sensor 
(exit 2 media shift 
HP).
Go to “Exit 2 
sensor (exit 2 
media shift HP) 
removal” on 
page 4-329.Replace the 
connection.
3Check the media shift motor for proper operation. 
1. Enter the Diagnostics Menu.
2. Touch MOTOR TESTS.
3. Touch Printer Motor Test.
4. Touch Exit2 shift mtr.
Does the above motor rotate properly?Go to step 5.Go to step 4. Step Check Yes No 
						

							2-160MFP Service Manual 7500-XXX
919.01 Exit 2 unit assembly connection failure
4Check the media shift motor for proper connection.
Is the above motor connected properly?Replace the media 
shift motor.
Go to “Exit 2 unit 
assembly removal” 
on page 4-315.Replace the 
connection.
5Perform a print test.
Does the error still occur?Replace the exit 
interface card 
assembly. 
Go to “Exit 
interface card 
assembly removal” 
on page 4-116.
Go to step 6.Problem solved.
6Perform 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
1Check the exit 2 unit assembly for proper installation.
Is the exit 2 unit assembly installed properly?Go to step 2.Reinstall the exit 2 
unit assembly, and 
POR.
Go to “Exit 2 unit 
assembly removal” 
on page 4-315.
2Check the exit 2 unit assembly connector.
Is the exit 2 unit assembly connector or the connector 
attached to the printer damaged?Replace the exit 2 
unit assembly or 
damaged connector.
Go to “Exit 2 unit 
assembly removal” 
on page 4-315.Go to step 3.
3Perform a print test.
Does the error still occur?Replace the exit 
interface card 
assembly.
Go to “Exit 
interface card 
assembly removal” 
on page 4-116.
Go to step 4.Problem solved.
4Perform 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 information2-161
7500-XXX
920.00 Fuser unit assembly on time failure
921.00 Over heat temperature failure
Step Check Yes No
1 Check the fuser unit assembly for a media jam. 
Open the printer left door assembly and check it.
Is there a media jam in the fuser unit assembly?Remove the 
media.Go to step 2.
2 Leave the printer powered on with the error code displayed 
for 10 minutes, then perform a POR.
Does the error still occur?Go to step 3. Problem solved.
3 Check the fuser unit assembly for proper installation. 
Open the printer left door assembly and check it.
Is the fuser unit assembly installed properly?Go to step 4. Install the fuser 
unit assembly 
properly.
4 Check the fuser unit assembly connection.
Is the fuser unit assembly properly connected?Go to step 5. Replace the 
connection.
5 Check between the LVPS card assembly P525 and the 
printer engine card assembly P401 for proper connection. 
Are the cards connected properly?Replace the fuser 
unit assembly. Replace the 
connection.
6 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the fuser unit assembly for proper installation.
Open the printer left door assembly and check it.
Is the fuser unit assembly installed properly?Go to step 2. Install the fuser 
unit assembly 
properly.
2 Check the fuser unit assembly for proper connection.  Go to step 3. Replace the 
connection.
3 Check the connection between the LVPS card assembly 
P525 and the printer engine card assembly P401.
Are the cards connected properly?Replace the fuser 
unit assembly. Replace the 
connection.
4 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved. 
						

							2-162MFP Service Manual 7500-XXX
922.00 Center thermistor failure
923.00 Rear thermistor failure
924.00 Pressure roll thermistor failure
Step Check Yes No
1 Check the fuser unit assembly for proper installation.
Open the printer left door assembly and check it.
Is the fuser unit assembly installed properly?Go to step 2. Install the fuser 
unit assembly 
properly.
2 Check the fuser unit assembly connection.
Is the fuser unit assembly properly connected?Replace the fuser 
unit assembly. Replace the 
connection.
3 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the fuser unit assembly for proper installation.
Open the printer left door assembly and check it.
Is the fuser unit assembly installed properly?Go to step 2. Install the fuser 
unit assembly 
properly.
2 Check the fuser unit assembly connection.
Is the fuser unit assembly properly connected?Replace the fuser 
unit assembly. Replace the 
connection.
3 Perform a print test.
Does the error continue?Replace the 
printer engine card 
assembly.
Go to “Printer 
engine card 
assembly 
removal” on 
page 4-117.Problem solved.
Step Check Yes No
1 Check the fuser unit assembly for proper installation.
Open the printer left door assembly and check it.
Is the fuser unit assembly installed properly?Go to step 2. Install the fuser 
unit assembly 
properly.
2 Check the fuser unit assembly connection.
Is the fuser unit assembly properly connected?Replace the fuser 
unit assembly. Replace the 
connection.