Lexmark X543 Service Manual

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with the ADF scan sensor ensure that the media is travelling at the correct speed through the scan area. The 
speed the document travels through the ADF scan area is dependent on the image DPI specified by the user.
7. After a predetermined number of counts, the media reaches the scan area and the image acquisition process 
is initiated. While the image acquisition process is executing, the ADF scan sensor is being polled to determine if 
the trailing edge of the media has reached the sensor. 
8. Once the trailing edge of the scan media has reached the ADF scan sensor, that sensor goes to the off 
position. After the ADF scan sensor is switched off, the image acquisition process continues for a predetermined 
length of time. 
9. When the image acquisition process is completed, the trailing edge of the media continues to the reverse 
point. If the scan job is simplex, only the media continues to the exit roller and exits the ADF.
10. If the scan job is a duplex scan job, a solenoid on the ADF is actuated when the trailing edge of the media 
reaches the reverse point. This solenoid moves a diverter gate to the down position and engages a reversing 
gear on the exit roll. 
11. The reversed exit roll pulls the paper back into the ADF. The transport roll then moves the media to the 
duplex sensor. When the duplex sensor is actuated, the exit roll stops. Also, the duplex sensor indicates that this 
is the second side of the media to be scanned. 
12. After actuating the duplex sensor, the transport roll moves the media to the take away roll and the ADF scan 
sensor. Like the first pass of the media, the image acquisition process is repeated for the second side of the 
media. 
13. When the trailing edge of the media reaches the reverse point the second time, the solenoid again moves the 
diverter gate to the down position and reverses the exit roll. The paper goes back into the ADF unit for a third 
time. The paper passes through the paper path, but no imaging occurs. This pass is to turn the paper over to the 
original side up. On the third pass of the media trailing edge over the reverse point, the solenoid is not actuated 
and the paper passes out of the ADF.  
						

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Color theory
What is RGB color?
Red, green, and blue light can be added together in various amounts to produce a large range of colors 
observed in nature. For example, red and green can be combined to create yellow. Televisions and computer 
monitors create colors in this manner. RGB color is a method of describing colors by indicating the amount of 
red, green, or blue needed to produce a certain color. 
What is CMYK color?
Cyan, magenta, yellow, and black inks or toners can be printed in various amounts to produce a large range of 
colors observed in nature. For example, cyan and yellow can be combined to create green. Printing presses, 
inkjet printers, and color laser printers create colors in this manner. CMYK color is a method of describing colors 
by indicating the amount of cyan, magenta, yellow, and black needed to reproduce a particular color.
How is color specified in a document to be printed?
Software programs typically specify document color using RGB or CMYK color combinations. Additionally, they 
allow users to modify the color of each object in a document. For more information, see the software program 
Help topics. 
How does the printer know what color to print?
When a user prints a document, information describing the type and color of each object is sent to the printer. 
The color information is passed through color conversion tables that translate the color into the appropriate 
amounts of cyan, magenta, yellow, and black toner needed to produce the desired color. The object information 
determines the application of color conversion tables. For example, it is possible to apply one type of color 
conversion table to text while applying a different color conversion table to photographic images. 
Should I use PostScript or PCL emulation? What settings produce the best color?
The PostScript driver is strongly recommended for best color quality. The default settings in the PostScript driver 
provide the preferred color quality for the majority of printouts.
Why doesnt the printed color match the color I see on the computer screen?
The color conversion tables used in Auto Color Correction mode generally approximate the colors of a standard 
computer monitor. However, because of technology differences that exist between printers and monitors, there 
are many colors that can also be affected by monitor variations and lighting conditions. For recommendations on 
how the printer color sample pages may be useful in solving certain color-matching problems, see “How can I 
match a particular color (such as a corporate logo)?” on page 3-62.
The printed page appears tinted. Can I adjust the color?
Sometimes a printed page may appear tinted (for example, everything printed seems to be too red). This can be 
caused by environmental conditions, paper type, lighting conditions, or user preference. In these instances, 
adjust the Color Balance setting to create a more preferable color. Color Balance provides the user with the 
ability to make subtle adjustments to the amount of toner being used in each color plane. Selecting positive or 
negative values for cyan, magenta, yellow, and black (from the Color Balance menu) will slightly increase or 
decrease the amount of toner used for the chosen color. For example, if a printed page has a red tint, then 
decreasing both magenta and yellow could potentially improve the color balance.  
						

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My color transparencies seem dark when they are projected. Is there anything I can 
do to improve the color?
This problem most commonly occurs when projecting transparencies with reflective overhead projectors. To 
obtain the highest projected color quality, transmissive overhead projectors are recommended. If a reflective 
projector must be used, then adjusting the Toner Darkness setting to 1, 2, or 3 will lighten the transparency. 
Make sure to print on the recommended type of color transparencies.
What is manual color correction?
When manual color correction is enabled, the printer employs user-selected color conversion tables to process 
objects. However, Color Correction must be set to Manual, or no user-defined color conversion will be 
implemented. Manual color correction settings are specific to the type of object being printed (text, graphics, or 
images), and how the color of the object is specified in the software program (RGB or CMYK combinations).
Notes:
Manual color correction is not useful if the software program does not specify colors with RGB or CMYK 
combinations. It is also not effective in situations in which the software program or the computer operating 
system controls the adjustment of colors.
The color conversion tables—applied to each object when Color Correction is set to Auto—generate 
preferred colors for the majority of documents. 
To manually apply a different color conversion table:
1.press Menu ( ) to open the Admin menus.
2.Select Settings, and press Select ().
3.Select Quality, and press Select ().
4.Select Color Correction, and press Select ().
5.Select Manual, and press Select ( ). 
The printer is in manual mode, and you need to select a color conversion table.
6.press Back ( ) to return to the Quality menu, select Manual Color, and press Select ().
7.Select the appropriate color conversion table for the affected object type.
Object type Color conversion tables
RGB Image
RGB Text
RGB GraphicsVivid—Produces brighter, more saturated colors and may be applied to 
all incoming color for mats.
sRGB Display—Produces an output that approximates the colors 
displayed on a computer monitor. Black toner usage is optimized for 
printing photographs.
Display—Tr u e  B l a c k—Produces an output that approximates the colors 
displayed on a computer monitor. Uses only black toner to create all 
levels of neutral gray.
sRGB Vivid—Provides an increased color saturation for the sRGB 
Display color correction. Black usage is optimized for printing business 
graphics.
Off—No color correction is implemented.
CMYK Image
CMYK Text
CMYK GraphicsUS CMYK—Applies color correction to approximate the SWOP 
(Specifications for Web Offset Publishing) color output.
Euro CMYK—Applies color correction to approximate EuroScale color 
output.
Vivid CMYK—Increases the color saturation of the US CMYK color 
correction setting.
Off—No color correction is implemented. 
						

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How can I match a particular color (such as a corporate logo)?
From the printer Quality menu, nine types of Color Samples sets are available. These are also available from the 
Color Samples page of the Embedded Web Server. Selecting any sample set generates a multiple-page printout 
consisting of hundreds of colored boxes. Either a CMYK or RGB combination is located on each box, depending 
on the table selected. The observed color of each box is obtained by passing the CMYK or RGB combination 
labelled on the box through the selected color conversion table. 
To print Color samples from the printer:
1.press Menu ( ) to open the Admin menus.
2.Select Settings, and press Select ().
3.Select Quality, and press Select ().
4.Select Color Samples, and press Select ().
5.Select the Color Conversion table to print, and press Select ( ). 
By examining Color Samples sets, a user can identify the box whose color is the closest to the desired color. The 
color combination labelled on the box can then be used for modifying the color of the object in a software 
program. For more information, see the software program Help topics. Manual color correction may be 
necessary to utilize the selected color conversion table for the particular object. 
Selecting which Color Samples set to use for a particular color-matching problem depends on the Color 
Correction setting being used (Auto, Off, or Manual), the type of object being printed (text, graphics, or images), 
and how the color of the object is specified in the software program (RGB or CMYK combinations). When the 
printer Color Correction setting is set to Off, the color is based on the print job information; and no color 
conversion is implemented. 
Note:  The Color Samples pages are not useful if the software program does not specify colors with RGB or 
CMYK combinations. Additionally, certain situations exist in which the software program or the computer 
operating system adjusts the RGB or CMYK combinations specified in the program through color management. 
The resulting printed color may not be an exact match of the Color Samples pages.
What are detailed Color Samples and how do I access them?
Detailed Color Samples sets are available only through the Embedded Web Server of a network printer. A 
detailed Color Samples set contains a range of shades (displayed as colored boxes) that are similar to a user-
defined RGBor CMYK value. The likeness of the colors in the set are dependent on the value entered in the 
RGB or CMYK Increment box. 
To access a detailed Color Samples set from the Embedded Web Server:
1.Open a Web browser.
2.In the address bar, type the network printer IP address.
3.Click Configuration.
4.Click Color Samples.
5.Click Detailed Options to narrow the set to one color range.
6.When the Detailed Options page appears, select a color conversion table.
7.Enter the RGB or CMYK color number.
8.Enter an Increment value from 1–255.
Note:  The closer the value is to 1, the narrower the color sample range will appear.
9.Click Print to print the detailed Color Samples set. 
						

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4.  Repair information
Warning:  Read the following before handling electronic parts.
Handling ESD-sensitive parts 
Many electronic products use parts that are known to be sensitive to electrostatic discharge (ESD). To prevent 
damage to ESD-sensitive parts, use the following instructions in addition to all the usual precautions, such as 
turning off power before removing logic boards:
Keep the ESD-sensitive part in its original shipping container (a special “ESD bag”) until you are ready to 
install the part into the machine.
Make the least-possible movements with your body to prevent an increase of static electricity from clothing 
fibers, carpets, and furniture.
Put the ESD wrist strap on your wrist. Connect the wrist band to the system ground point. This discharges 
any static electricity in your body to the machine.
Hold the ESD-sensitive part by its edge connector shroud (cover); do not touch its Pin. If you are removing 
a pluggable module, use the correct tool.
Do not place the ESD-sensitive part on the machine cover or on a metal table; if you need to put down the 
ESD-sensitive part for any reason, first put it into its special bag.
Machine covers and metal tables are electrical grounds. They increase the risk of damage because they 
make a discharge path from your body through the ESD-sensitive part. (Large metal objects can be 
discharge paths without being grounded.)
Prevent ESD-sensitive parts from being accidentally touched by other personnel. Install machine covers 
when you are not working on the machine, and do not put unprotected ESD-sensitive parts on a table.
If possible, keep all ESD-sensitive parts in a grounded metal cabinet (case).
Be extra careful in working with ESD-sensitive parts when cold-weather heating is used, because low 
humidity increases static electricity. 
						

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Removal procedures
Notes:
Some removal procedures require removing cable ties. You must replace cable ties during reassembly to 
avoid pinching wires, obstructing the paper path, or restricting mechanical movement.
Remove the waste toner bottle, color toner cartridges, imaging unit, and media tray before removing other 
printer parts. The imaging unit should be carefully set on a clean, smooth, and flat surface. It should also 
be protected from light while out of the printer. 
Unless otherwise stated, reinstall the parts in reverse order of removal. 
When reinstalling a part held with several screws, start all screws before final tightening. 
Print engine removal procedures
Notes: 
Remove the waste toner container, color toner cartridges, imaging unit, and media tray before removing 
other printer parts. The imaging unit should be carefully set on a clean, smooth, and flat surface. It should 
also be protected from light while out of the printer. 
We recommend disconnecting all external cables from the printer to prevent damage during service. 
Unless otherwise stated, reinstall the parts in reverse order of removal. 
When reinstalling a part held with several screws, start all screws before final tightening. 
Front cover assembly removal
1.Remove the media tray.
2.Open the front cover.
3.Remove the front middle cover (optional). See “Front middle cover removal” on page 4-4.
CAUTION
Remove the power cord from the electrical outlet before you connect or disconnect any cable 
or electronic board or assembly for personal safety and to prevent damage to the printer. 
Disconnect any connections between the printer and PCs/peripherals.  
						

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4.Remove the five screws (A) from the cable cover.
5.Remove the cable cover.
6.Remove the screw (B) securing the right restraining strap to the front cover.
Note:  Support the door with one hand after removing the screw holding the restraining strap. This is the 
longest screw of the eight. The two flat head Phillips screws are used in the door hinge.
7.Remove the two screws (C) securing the interlock and cable.
8.Route the cable through the right hinge.
Note:  Make a note of the interlock sensor cable routing through the right hinge and front door.
9.Remove screw (D) securing the restraining strap to the left side of the front door.
10.Lower the front cover to align the flats on the hinges, and remove the front cover. 
ABC
D 
						

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Front middle cover removal
1.Open the front cover.
2.Remove the five screws (A) attaching the front middle cover to the lower front cover.
3.Pull the front middle cover away from the front cover.
Left cover removal
1.Remove the media tray.
2.Open the front cover.
3.Position the printer with the left side hanging over the edge of the table.
A 
						

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4.Remove the three screws (A) on the rear side of the left cover.
A 
						

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5.Remove the screw (B) on the bottom of the cover. 
6.With a hand on the bottom of the cover, ease the cover over the off/on switch, and rotate the cover away 
from the printer.
Warning:  Be careful not to damage the rear tab at the upper rear side of cover.
Installation note: When replacing the left cover, flex the cover slightly to engage the tab near the power 
swi tc h .
B