Lexmark C736 Service Manual

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2.Loosely attach the three printhead mounting screws (B).
Warning:  Do not fully tighten the printhead mounting screws until skew has been adjusted. 
3.Lightly tighten the alignment screw (C). 
4.Feed the ground cable through the hole in bottom leftside frame. 
						

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5.Replace the system board support shield screws (E): 
a.Loosely attach the two mounting screws (E2)
b.Set the system board support shield in place.
Check that the ribbon mirror motor cable (white) and the printhead cable (bottom) do not rub against 
the edges of the frame.
c.Replace the remaining system board support shield screws in the following order:
•Replace the four screws (E1) from the inner right side of the support shield.
•Tighten the two mounting screws (E2) to the top of the support shield.
•Replace the three screws (E3) from the bottom of the support shield, and two screws from the 
top.
•Replace the five mounting screws (E4, E5) to the outer left side of the printer. 
•Reattach the printhead ground cable (E6) to the fourth screw from the top. 
						

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6.Replace the system board. 
a.Place the system board in position.
Check that the mirror motor cable and the printhead cable do not rub against the edges of the frame.
b.Replace the nine screws (F) in the system board in the following order:
•Loosely attach the four corners (F1) in a clockwise order, beginning with the left top corner.
•Replace the USB connector screw (F2).
•Loosely attach the left center side, top center, and right center side (F3).
•Tighten the top left corner and top right corner.
•Replace the two screws on the center bottom (F4).
•Tighten the bottom left and bottom right corners (F1).
c.Route the cables through the access holes on the right side of the printer. 
						

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d.Replace all the screws (G) from the left side of the printer, including:
•Ethernet port connector (1 screws)
•Modem shield (1 screws)
•Hard disk shield (2 screws)
•Ground screw (1 screw)
Note:  Be sure to attach the ground wire (H) to the ground screw.
e.Reconnect all the cables to the system board. Use the diagram below for a guideline.
Warning:  Be careful reconnecting the printhead ribbon cable (J). It can be damaged and should be 
handled carefully. A flat ribbon cable can easily be damaged and should be connected gently by hand.
f.Install the hard disk if appropriate. 
						

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7.Replace the LVPS.
a.Install the LVPS, and make sure the cable is in the cable guides, and not behind the LVPS.
b.Reconnect the cable to the LVPS.
c.Replace the five LVPS mounting screws.
d.Reconnect the cable in connector JLVPS1 on the system board.
8.Replace the right cover.
a.Slide the right cover up until it locks into position.
Be sure the tab in the top access cover engages the slot in the right cover. 
b.Replace the screw at the bottom of the rear frame cover.
c.Replace the two screws securing the right cover at the bottom.
d.Replace the metal screw at the bottom on the inside front cover
e.Replace the plastic screw at the top on the inside of the front cover.
9.Replace the left cover, the rear left cover, and the paper tray dust cover.
a.Place the paper tray dust cover into position.
b.Slide the cover down until it locks into place. 
Be sure the post in the top access cover engages the hole in the left cover, and that the post in the 
paper tray dust cover engages the hole in the left cover properly.
c.Replace the taptite screw on the rear frame cover.
d.Replace the three screws on the left cover.
10.Replace the rear frame cover.
a.Replace the rear frame cover.
b.Tighten the eight screws. 
11.Replace the rear upper cover (two screws).
12.Reinstall the transfer module with the photoconductor units still attached.
13.Reconnect the transfer module cable. 
14.Replace the toner cartridges. 
15.Reinstall the fuser.
16.Close the top access door. 
17.Close the front access door.
18.Replace the paper tray.
Printhead alignment
Note:  The printhead mounting screws should be initially tightened just enough to hold the printhead in the 
printer. 
There is one printhead that houses the four color planes. The black plane is aligned to the printer, and the color 
planes are internally aligned to black. Electrical alignment is done to fine tune the alignment of the color planes 
to the black plane after the printhead is installed, and black skew is adjusted using the alignment screw.
Skew (black)
1.Plug the electrical cord into the printer.
2.Plug the electrical cord into the outlet. 
3.The first step in aligning the printhead is to set the skew for black. 
a.Enter the Diagnostic menu (turn off the printer, press and hold   and  , turn on the printer, and 
release the buttons when the clock graphic displays).
b.Select REGISTRATION from the DIAGNOSTICS menu, and press Select ().
c.Select Skew, and press Select ().
d.Use   or   to set the Skew to zero, and press Select ().
e.Press Back (). 
						

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f.Scroll down to Quick Test, and press Select  . A page similar to this one prints: 
						

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g.Adjust the printhead alignment screw (A) to change the skew and straighten the image on the 
printout.
If the top right alignment marks are lower than the top left alignment marks, rotate the alignment 
screw counterclockwise a full revolution, and print the Quick Test page. Repeat adjusting the screw 
and printing the Quick Test until the top alignment marks are the same distance from the top of the 
media.
Note:  One rotation of the printhead alignment screw equals approximately 0.5 millimeter movement 
of the top edge print alignment marks.
h.When the top right and top left alignment marks are both showing and are even on the page, the 
skew is aligned.
4.Tighten the printhead mounting screws.
a.Turn off the printer.
b.Disconnect the power cord from the electrical outlet.
c.Disconnect the transfer module cable. 
d.Press the two tabs on either side of the transfer module, and lift out the transfer module with the 
photoconductor units in place.
Straight Skewed 
						

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e.Remove all of the toner cartridges.
f.Tighten the printhead mounting screws in the following order: B1, B2, and B3.
5.Replace the printhead alignment screw cover (C).
Be sure to replace the screw cover so that the notch in the cover faces to the rear of the printer. This 
makes it much easier to remove the next time.
6.Replace the toner cartridges. 
7.Reinstall the transfer module and the photoconductor units.
8.Connect the transfer module cable.  
						

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Registration (black)
Top Margin
1.Reconnect the power cord to the electrical outlet, but do not turn on the printer yet.
2.Enter Diagnostic mode (press and hold   and  , turn on the printer, and release the buttons when the 
clock graphic displays).
3.Select REGISTRATION, and press Select .
4.Select Quick Test, and press Select   or use the last Quick Test you used to adjust skew.
5.Select Top Margin, and press Select .
6.Adjust the values until both top alignment marks are on the top edge of the print. 
•Increasing the value ( ) moves the top alignment marks down on the page. 
•Decreasing the value ( ) moves the top alignment marks up on the page. 
7.Press Select ( ) to save the value. 
8.Print the Quick Test page, and check the top alignment marks. Repeat adjustment of the top margin and 
printing of the Quick Test page until top margin is set.
Bottom Margin
1.Select Bottom Margin, and press Select . 
2.Adjust the bottom margin until the points of the bottom margin alignment marks are visible and touching 
the edge of the paper.
•Increasing the value ( ) moves the bottom alignment marks up on the page.
•Decreasing the value ( ) moves the bottom alignment marks down on the page.
3.Press Select ( ) to save the value. 
4.Print the Quick Test page, and repeat this process until the bottom margin is adjusted. 
						

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Left Margin
1.Adjust the left margin until the points of the left alignment marks touch the edge of the page.
•Increasing the value ( ) moves the bottom alignment marks up on the page.
•Decreasing the value ( ) moves the bottom alignment marks down on the page.
2.Press Select ( ) to save the value. 
3.Print the Quick Test page, and check the left alignment marks each time until you are satisfied.
Right Margin
1.Adjust the right margin until the points of the left alignment marks touch the edge of the page.
•Increasing the value ( ) moves the bottom alignment marks up on the page.
•Decreasing the value ( ) moves the bottom alignment marks down on the page.
2.Press Select ( ) to save the value. 
3.Print the Quick Test page, and check the results. Repeat if necessary.
4.When the registration is complete, proceed to the color alignment.
Alignment (cyan, yellow, and magenta)
1.
Select Back ( ) until you reach the top menu.
2.Select ALIGNMENT MENU, and press Select ().
3.Select Cyan, and press Select (). 
4.Select Top Margin, and press Select ().
5.Use  and  to set Top Margin to zero, and press Select ( ) to save the value.
6.Do the same for Left Margin, Right Margin, Bottom Margin, Skew, and Bow. 
It is important to set all the values to zero before starting.