Lexmark C 746 Service Manual

							Diagnostic aids3-19
 5026
Go Back Previous
Next
6.Use   or   to select the margin setting you need to change, and press  . For C748x, use   or   to 
select the margin setting you need to change, and touch  .
•Each increment shifts the duplex left margin by 4 pixels at 600 dpi (0.00666 inches or 0.1693 mm). 
•The Left Margin range is -50 to +50, and the default value is 0.
•An increase moves the margin to the right, and a decrease moves the margin to the left.
Sensor Test
There are two groups of sensors tests, static sensors and dynamic sensors. 
To run the Sensor Test:
1.Select Sensor Tests from the Diagnostics Menu.
2.Select Static Sensors or Dynamic Sensors.
•For static sensors—view the current status. Exit menus and re-enter to change state.
•For dynamic sensors—view the current status and toggle the state to test the sensor.
3.Select the particular sensor you need to test. 
Touch Back or press   to exit the test.
Sensor type Sensor name Possible values Sensor activation
Static sensorsWaste Toner Empty, Full, or 
MissingN/A
Belt Waste Empty or 
percentage fullN/A
Fuser Temp Degrees (C) N/A
Fuser BUR Temp Degrees (C) N/A
Power Voltage Open and close the front access door. 
						

							3-20Service Manual 5026 
Go Back Previous
Next
Printhead Tests
Mirror Motor Test
1.
Select PRINTHEAD TESTS from the Diagnostics Menu.
2.Select Mirror Motor Test.
The panel displays Motor Running. 
After the test completes, the panel displays either Pass or Fail.
To stop the test, Touch Back or press  .
Servo Laser Test
1.
Select PRINTHEAD TESTS from the Diagnostics Menu. 
2.Select Servo Laser Test.
The panel displays Motor Running. After the test completes, the panel displays either Pass or Fail.
To stop the test, Touch Back or press  .
Device Tests
Note:  These tests only appear if the flash or disk option is installed. Dynamic 
sensorsFuser Exit  Open/Closed Open the top access cover. Activate the fuser 
exit flag. The sensor should change state.
Input Open/Closed Remove the paper tray 1. Activate the input 
sensor flag. The sensor should change state.
Door Open/Closed Open the front door. The sensor should 
change state.
Narrow  Media Open/Closed Test the MP feeder tray by inserting a sheet of 
paper, and pushing up to sensor. The sensor 
should change state. 
K Toner Open/Closed Remove the black toner cartridge. Shine a 
flashlight on the toner level sensor. The 
sensor should change state.
M Toner Open/Closed Remove the magenta toner cartridge. Shine a 
flashlight on the toner level sensor. The 
sensor should change state.
C Toner Open/Closed Remove the cyan toner cartridge. Shine a 
flashlight on the toner level sensor. The 
sensor should change state.
Y Toner Open/Closed Remove the yellow toner cartridge. Shine a 
flashlight on the toner level sensor. The 
sensor should change state.
TPS (toner patch 
sensor)Open/Closed Open the front access door. Slip a piece of 
paper between the TPS and the transfer 
module. The sensor should change state.
Bubble Open/Closed Open the front door. Activate the fuser entry 
flag. The sensor should change state.
Dynamic MPF Open/Closed Test by removing the MPF pick arm and 
activating the paper present sensor or remove 
the tray and shine a flashlight on the paper 
present sensor.
Other SensorsBin Full Test Open/Closed Move the bin full sensor flag (located on the 
fuser) up and down to toggle the sensor state. Sensor type Sensor name Possible values Sensor activation 
						

							Diagnostic aids3-21
 5026
Go Back Previous
Next
Quick Disk Test
This test performs a non-destructive read/write on one block per track on the disk. The test reads one block on 
each track, saves the data, and proceeds to write and read four test patterns to the bytes in the block. If the 
block is good, the saved data is written back to the disk.
To run the Quick Disk Test:
1.Select DEVICE TESTS from the Diagnostics Menu.
2.Select Quick Disk Test.
•The power indicator blinks while the test is in progress.
•Quick Disk Test/Test Passed is displayed if the test passes and the power indicator turns on solid.
•Quick Disk Test/Test Failed is displayed if the test failed and the power indicator turns on solid.
You cannot stop the test while it is running, but when it is complete, press   to return to DEVICE TESTS. 
						

							3-22Service Manual 5026 
Go Back Previous
Next
Disk Test/Clean
Warning:This test destroys all data on the disk and should not be attempted on a good disk. This test may run 
approximately 1½ hours depending on the disk size.
To run the Disk Test/Clean Test:
1.Select DEVICE TESTS from the Diagnostics Menu.
2.Select Disk Test/Clean.
Files will be lost/Go or Stop? is displayed to warn the user.
3.To exit the test immediately and return to DEVICE TESTS, touch Back or press  . To continue with the 
test, press   or touch  .
Disk Test/Clean/BAD:000000 00% is displayed. The screen updates periodically, indicating the percentage 
of test completed and the number of bad blocks found.
4.The power indicator blinks during the test. Touch Back or press   to cancel the test. 
•Once the test is complete, the power indicator turns on solid and a message displays. 
•xxxx Bad Blocks/yyyyyy Usable is displayed if fewer than 2000 bad blocks are detected. xxxx 
indicates the number of bad blocks, and yyyyyy indicates the number of usable blocks.
•xxxx Bad Blocks/Replace Disk is displayed if more than 2000 bad blocks are detected. The disk 
cannot be recovered because too many bad blocks exist on the disk.
5.Touch Back or press   to return to DEVICE TESTS.
Flash Test
This test causes the file system to write and read data on the flash to test the flash.
Warning:This test destroys all data on the flash because the flash is reformatted at the end of the test.
To run the Flash Test:
1.Select DEVICE TESTS from the Diagnostics Menu.
2.Select Flash Test,.
•The power indicator blinks while the test is running.
•Flash Test/Test Passed is displayed if the test passes and the power indicator turns on solid.
•Flash Test/Test Failed is displayed if the test fails and the power indicator turns on solid.
3.Touch Back or press   to return to DEVICE TESTS.
Printer Setup
Defaults
U.S./Non-U.S. defaults changes whether the printer uses the U.S. factory defaults or the non-U.S. factory 
defaults. The settings affected include paper size, envelope size, PCL symbol set, code pages, and units of 
measure.
Warning:Changing this setting resets the printer to factory defaults, and data may be lost. It cannot be undone. 
						

							Diagnostic aids3-23
 5026
Go Back Previous
Next
Page Counts
You can view, but not change any of the three counts displayed under PAGE COUNTS.
To view the Prt Color Pg Count, the Prt Mono Pg Count, or the Perm Page Count:
1.Select PRINTER SETUP from the Diagnostics Menu.
2.Select the page count you wish to view:
•Prt Color Pg Count
•Prt Mono Pg Count
•Perm Page Count
Touch Back or press   to return to PRINTER SETUP.
Serial Number
The serial number can only be viewed and cannot be changed.
To view the serial number:
1.Select PRINTER SETUP from the Diagnostics Menu.
2.Select Serial number.
Touch Back or press   to return to PRINTER SETUP.
Engine Setting 1 through 4
Warning:Do not change these settings unless requested to do so by your next level of support. 
Model Name
The model name can only be viewed and cannot be changed.
Configuration ID
The two configuration IDs are used to communicate information about certain areas of the printer that cannot be 
determined using hardware sensors. The configuration IDs are originally set at the factory when the printer is 
manufactured. However, the servicer may need to reset Configuration ID 1 or Configuration ID 2 whenever the 
system board is replaced. The IDs consist of eight digits. The first seven digits in each ID are hexadecimal 
numbers, while the last digit is a checksum of the preceding seven digits. Each ID can contain a combination of 
the digits 0 through 9, and A through F.
Note:  When the printer detects a Configuration ID that is not defined or invalid, the following occurs:
•The default standard model Configuration ID is used instead.
•Configuration ID is the only function available in DIAGNOSTICS.
•Unless the menu is in DIAGNOSTICS, Check Config ID displays. 
To set the configuration ID:
1.Select Printer Setup from the Diagnostic mode.
2.Select Configuration ID from the Printer Setup menu.
3.The value for Configuration ID 1 displays.
4.Enter the Configuration ID 1.
•Use the keypads on the operator panel to enter the configuration ID.
•Press   or touch Clear to delete the default configuration ID displayed.
•After the last digit is changed, press   or touch   to validate the Configuration ID 1.
If Invalid ID appears, the entry is discarded.
If the process is successful, Submitting Changes appears on the display. 
						

							3-24Service Manual 5026 
Go Back Previous
Next
5.Repeat the steps for entering the Configuration ID 2, and press .
Note:  The printer will NOT perform an automatic POR after the Configuration IDs are accepted.
Reset color calibration (Reset Color Cal)
The Reset Color Cal enables the alignment of the color planes using pre-programmed values. Automatic Color 
Adjust Calibration may be more effective.
1.Select PRINTER SETUP from the Diagnostics Menu.
2.Select Reset Color Cal.
Resetting displays on the screen.
3.The printer returns to the previous screen when calibration is complete.
Parallel 1 strobe adjustment (Par 1 Strobe Adj)
Note:  This setting appears only if the printer has a parallel port available in the PCI slot 1. 
This setting enables the servicer to adjust the amount of time the strobe is sampled in order to determine if valid 
data is available on the parallel port. The range of values is -4 to 6. Each time this value is incremented by 1, the 
strobe is sampled 50 ns (nanoseconds) longer. Each time this value is decreased by 1, the strobe is sampled 50 
ns less often. When the value of this setting is 0, the factory default is used to determine the length of time the 
strobe is sampled. If the servicer, for example, decreased the value from 0 to 3, the strobe will be sampled for 
150 ns longer than the factory setting.
Motor Calibration
This test is run to calibrate the leading edge of the paper to each transfer station.
1.Select MOTOR TESTS from the Diagnostics Menu. 
2.Select Motor Calibration.
The printer generates eight pages as part of this test.
To stop the test, press  .
EP Setup
EP Defaults
This setting is used to restore each printer setting listed in EP SETUP to its factory default value. Sometimes this 
is used to help correct print quality problems.
To restore EP Defaults:
1.Select EP SETUP from the Diagnostics Menu.
2.Select EP Defaults.
3.Select Restore to reset the values to the factory settings, and select Do Not Restore to exit without 
changing the settings.
Fuser temperature (Fuser Temp)
This adjustment can be used to help solve some customer problems with paper curl on low grade papers and 
problems with letterheads on some types of media. 
The fuser temperature can be adjusted to: Low, Normal, High. The default is Normal. 
						

							Diagnostic aids3-25
 5026
Go Back Previous
Next
DC Charge Adjust, Dev Bias Adj, Transfer Adjust
Each of these three settings enables you to adjust the high voltage levels controlling the electrophotographic 
process. You will use these settings to compensate for unusual operating circumstances such as high humidity. 
The printer uses the value of these settings together with other settings to calculate printing speed and media 
selection.
Reports
Menu Settings Page
The Menu Settings Page is a list of DIAGNOSTICS settings with the current value.
Event Log
Display Log
The event log provides a history of printer errors. It contains the 12 most recent errors that have occurred on the 
printer. The most recent error displays in position 1, and the oldest error displays in position 12 (if 12 errors have 
occurred). If an error occurs after the log is full, the oldest error is discarded. Identical errors in consecutive 
positions in the log are entered, so there may be repetitions. All 2xx and 9xx error messages are stored in the 
event log.
To view the event log:
1.Select EVENT LOG from the Diagnostics Menu.
2.Select Display Log. 
Touch Back ore press   to return to the EVENT LOG menu. 
						

							3-26Service Manual 5026 
Go Back Previous
Next
Print Log
Additional diagnostic information is available when you print the event log from DIAGNOSTICS rather than 
CONFIG MENU. 
The Event Log printed from DIAGNOSTICS includes:
•Detailed printer information, including code versions
•Time and date stamps
•Page counts for most errors
•Additional debug information in some cases
The printed event log can be faxed to Lexmark or your next level of support for verification or diagnosis.
To print the event log:
1.Select EVENT LOG from the Diagnostics Menu.
2.Select Print Log.
Touch Back or press   to return to EVENT LOG. 
Clear Log
Use Clear Log to remove the current information in the Event Log. This affects both the viewed log and the 
printed log information.
1.Select EVENT LOG from the Diagnostics Menu.
2.Select Clear Log.
3.Select YES to clear the Event Log or NO to exit the Clear Log menu.
If YES is selected, Deleting EVENT LOG displays on the screen.
Touch Back or press   to return to EVENT LOG.
EXIT DIAGNOSTICS
The printer performs a power-on reset and returns to normal mode. 
						

							Diagnostic aids3-27
 5026
Go Back Previous
Next
Configuration menu (CONFIG MENU)
Available tests
The tests display on the operator panel in the order shown. 
Reset Fuser Cnt See “Reset Fuser Cnt” on page 3-28. 
Color Lock Out  See “Color Lock Out” on page 3-28.
Print Quality Pages See “Print Quality Pages” on page 3-28. 
Reports
Menu Settings Page See “Menu Settings Page” on page 3-29.
Event Log See “Event Log” on page 3-29.
Color Trapping See “Color Trapping” on page 3-29. 
Tray Insert Msg See “Tray Insert Msg” on page 3-29.
Panel Menus See “Panel Menus” on page 3-29. 
PPDS Emulation See “PPDS Emulation” on page 3-30. 
Download Emuls (if available) See “Download Emuls” on page 3-30. 
Demo Mode See “Demo Mode” on page 3-30. 
Factory Defaults See “Factory Defaults” on page 3-30. 
Energy Conserve See “Energy Conserve” on page 3-30. 
Automatic Color Adjust See “Automatic Color Adjust” on page 3-31. 
Auto Align Adj See “Auto Align Adj” on page 3-31. 
Color Adj State See “Color Adj State” on page 3-31.
Enforce Color Order See “Enforce Color Order” on page 3-31. 
Color Alignment See “Color Alignment” on page 3-31. 
Motor Calibration See “Motor Calibration” on page 3-32. 
Paper Prompts See “Paper Prompts” on page 3-32. 
Envelope Prompts See “Envelope Prompts” on page 3-32. 
Action for Prompts See “Action for Prompts” on page 3-32. 
Jobs on Disk (if hard disk is installed) See “Jobs on Disk” on page 3-32. 
Disk Encryption (if hard disk is 
installed)See “Disk Encryption” on page 3-33. 
Wipe Disk (if hard disk is installed) See “Wipe Disk” on page 3-33.
Wipe All Settings See “Wipe All Settings” on page 3-33.
Duplex Gloss See “Duplex Gloss” on page 3-34. 
Font Sharpening See “Font Sharpening” on page 3-34.
Require Standby See “Require Standby” on page 3-34.
UI Automation See “UI Automation” on page 3-34.
Key Repeat Initial Delay See “Key Repeat Initial Delay” on page 3-34.
Key Repeat Rate See “Key Repeat Rate” on page 3-34.
Clear Custom Status See 
“Clear Custom Status” on page 3-34.
USB Speed See “USB Speed” on page 3-34.
Automatically Display Error Screens See “Automatically Display Error Screens” on page 3-35. 
						

							3-28Service Manual 5026 
Go Back Previous
Next
Reset Fuser Cnt
Resets the fuser count value to zero. The Event Log records each time that a user executes the Reset Fuser 
Count operation. See “Event Log” on page 3-29 for more information. This setting only appears if the 
Maintenance Warning and Intervention function is enabled in the printer Configuration ID.
To reset the fuser count:
1.Select Reset Fuser Cnt from the Configuration Menu.
To cancel a reset, touch Back or press  . 
2.Select Reset Fuser Cnt. Once you select Reset Fuser Cnt, you cannot cancel.
Resetting Fuser Counter appears.
Color Lock Out
Select On when printing for extended periods with only black toner. This saves the color toner cartridges (cyan, 
magenta, and yellow) and photoconductor units from excessive wear. In addition to setting the values, the cyan, 
magenta, and, yellow toner cartridges and their matching photoconductor units must be removed from the 
printer. The default value is Off.
1.Select Color Lock Out from the Configuration Menu.
2.Select On. 
3.Remove all color supplies. Remove the color cartridges and the color photoconductor units. Leave only the 
black supplies.
4.Select Exit Config menu, or power off and on again.
Note:  
•If On is selected, and the color supplies are left installed when the printer is returned to normal mode, the 
printer displays Remove All Color Supplies. Remove all the color supplies, and press   or touch  . 
•If Off is selected, then at step 3, install all color supplies. If the supplies are not installed when the printer 
returns to normal mode, the printer displays 31 Missing or Defective {color} Cartridge. Replace the 
color cartridges and color photoconductors, and press   or touch  .
Print Quality Pages
To help isolate print quality problems, print the Print Quality Test Pages. The pages are formatted. The Printing 
Quality Test Pages message appears, then the pages print. The message remains on the operator panel until 
all the pages print. 
Press   or touch   to print the pages. The Print Quality Test Pages contain several pages. The first page 
which is printed in English text only contains a mixture of text and graphics. The information includes values of 
the Quality Menu settings in Settings and printer and toner cartridge configuration information. The remaining 
pages contain only graphics. For samples of the pages, see “Print quality test pages (Print Quality Pages)” 
on page 3-13.
Reports
Exit Config This selection exits Configuration Menu, and Resetting the Printer 
displays. The printer performs a POR and returns to normal mode.