Lexmark X 850 Owners Manual

Diagnostic information2-133
7500-XXX
843.00 Sensor (scanner HP) failure
Step Check Yes No
1 Check the scanner carriage rails.
Is there any foreign substance on the scanner rails?Clean and 
lubricate the 
scanner carriage 
rails.Go to step 2.
2 Check the sensor (scanner HP) for operation. 
Perform the sensor (scanner HP) test.
Remove the large platen glass. Go to “Large platen glass 
removal” on page 4-142.
1. Enter the Diagnostics Menu.
2. Touch SCANNER TESTS.
3. Touch Sensor Tests.
4. Touch Scanner HP....

2-134MFP Service Manual 7500-XXX
843.01 Scanner carriage over run failure
843.10 ADF RAM test failure
843.11 ADF EEPROM failure
Step Check Yes No
1 Check the connections of the scanner controller card 
assembly.
Are the connectors of the scanner controller card assembly 
connected properly?Go to step 2. Connect each 
connector of the 
scanner 
controller card 
assembly 
properly.
2 Perform a POR.
Does the error remain when the power is turned off/on?Replace the 
scanner 
controller card 
assembly. 
Go to...

Diagnostic information2-135
7500-XXX
843.12 ADF pick roll position lift up failure
2 Perform a POR.
Does the error remain when the power is turned off/on?Replace the 
ADF controller 
card assembly. 
Go to “ADF 
controller card 
assembly 
removal” on 
page 4-167.Problem solved.
Step Check Yes No
1 Check the feed/pick roll assembly.
Remove the left cover media guide. Does The feed/pick roll 
assembly moves smoothly up/down when the gears are 
manually rotated?Go to step 2. Replace the feed/
pick roll...

2-136MFP Service Manual 7500-XXX
843.20 Scanner unit assembly connection failure
843.21 Scanner unit assembly EEPROM failure 
5 Check the pick roll position motor assembly for connection.
Is the above motor connected properly?Replace the 
pick roll position 
motor 
assembly.
Go to “Pick roll 
position motor 
assembly 
removal” on 
page 4-182.Replace the 
connection.
6 Place an undamaged document in the ADF, and perform a 
ADF test.
Does the error remain?Replace the 
ADF controller 
card assembly. 
Go to...

Diagnostic information2-137
7500-XXX
843.22 Scanner unit assembly EEPROM sub system failure
843.23 Scanner cooling fan failure
2 Perform a POR.
Does the error remain when the power is turned off/on?Replace the 
ADF controller 
card assembly. 
Go to “ADF 
controller card 
assembly 
removal” on 
page 4-167.Problem solved.
Step Check Yes No
1 Check the connection of each scanner controller card 
assembly connector.
Are the connectors of the scanner controller card 
assembly connected properly?Go to step 2....

2-138MFP Service Manual 7500-XXX
843.24 Image processing failure
843.25 Scanner controller card assembly failure 1
3 Perform a POR.
Does the error remain when the power is turned off/on?Replace the 
scanner 
controller card 
assembly. 
Go to “Scanner 
controller card 
assembly 
removal” on 
page 4-143.Problem solved.
Step Check Yes No
1 Check the connections of the scanner controller card 
assembly.
Are the connectors of the scanner controller card assembly 
connected properly?Go to step 2. Connect each...

Diagnostic information2-139
7500-XXX
843.26 Scanner controller card assembly failure 2
844.00 Exposure lamp failure
3 Perform a POR.
Does the error remain when the power is turned off/on again?Replace the 
scanner PS card 
assembly. 
Go to “Scanner 
PS card 
assembly 
removal” on 
page 4-154.Problem solved.
Step Check Yes No
1 Check the connection of each scanner controller card 
assembly connector.
Is each connector of scanner controller card assembly 
connected properly?Go to step 2. Connect each...

2-140MFP Service Manual 7500-XXX
844.01 White reference/exposure lamp illumination failure
2 Check the exposure lamp for connection.
Is the above component connected properly?Replace the 
exposure lamp.
Go to “Exposure 
lamp removal” 
on page 4-158.Replace the 
connection.
3 Check the exposure lamp PS card assembly.
Is the above card properly connected to the scanner 
controller card assembly?Replace the 
exposure lamp 
PS card 
assembly.
Go to “Exposure 
lamp PS card 
assembly 
removal” on 
page...

Diagnostic information2-141
7500-XXX
2Remove the large platen glass. Check the bottom of the large 
platen glass in the vicinity the white reference strip for 
contamination.
Is the vicinity of white reference strip contaminated?Clean the bottom 
of the large 
platen glass in 
the vicinity of the 
white reference 
strip.
Reinstall the 
large platen 
glass properly.
Go to step 3.Go to step 4.
3Perform a POR.
Does the error remain?Go to step 4. Problem solved.
4Check the exposure lamp for operation....

2-142MFP Service Manual 7500-XXX
845.00 CCD failure
845.01 CCD initialization (lamp on) failure
Step Check Yes No
1 Check the CCD/lens assembly connection.
Is the CCD/lens assembly connected properly?Go to step 2. Replace the 
connection.
2 Check all the connections on the scanner controller card 
assembly.
Are all the connections connected properly?Replace the 
CCD/lens 
assembly.Replace the 
connection.
3 Perform a POR.
Does the error remain?Replace the 
scanner 
controller card 
assembly.
Go to...