Lexmark C 746 Service Manual

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7.Touch Quick Test in the Cyan menu.
Two pages print. You may have to print these pages several times until you get T (Top Margin) and 
Z (Skew) aligned. Do not go to step 2 until T and Z are aligned. The first page is similar to the following: 
						

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8.Determine the line under Fine Adjustment that is closest. If the value is beyond the Fine Adjustment scale, 
use either of the Coarse Adjustment scales.
9.Enter the number determined from the Fine Adjustment scale or the Coarse Adjustment scales on the part 
of the page for the “T” value. The current value is automatically entered on the sheet. At this point, it should 
be zero.
10.Enter the “New Cyan T value” on the operator panel and touch   to save the value. 
11.Reprint the Quick Test, and evaluate whether you are at zero changes. 
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12.Repeat this process for skew (Z). Dont forget to subtract the T value and add the current cyan Z value to 
obtain the new skew (Z) value.
An example is shown below:
13.Continue to follow the directions on the bottom of the first page to find the Cyan Top Margin (T), the 
Skew (Z), and on the second page of the Quick Test page, the Left Margin (L), Right Margin (R), and 
Bow (P).
14.Repeat steps 1 through 13 for yellow and magenta.
Note:  Start each color group by setting the Top Margin, Left Margin, Right Margin, Bottom Margin, Skew, and 
Bow to zero.
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Printer removal procedures
Precautions to take before maintenance work
Do not implement any operation, removal, or modification and so on, which is not presented in this manual. 
1.Turn the printer power off and unplug the power cable from the outlet prior to starting 
removals or checks.
2.Prior to starting any repairs, read and understand the warnings in this manual. 
•High temperature
•High voltage 
•Laser radiation
3.Confirm the direction of all parts and screw lengths during removal/replacement. 
4.Utilize the proper cleaning procedures/solvents during maintenance.
5.Confirm that all parts and covers are properly installed and assembled prior to starting the print test. 
						

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Cover removals
Front access cover assembly removal
See Front access door cover assembly for the part number for the models you need on page 7-3.
1.Remove the paper tray.
2.Disconnect the transfer module cable (A). 
3.Press the two tabs (B) to release the front access door cover assembly.
4.Press the two tabs (C) on either side of the transfer module, and lift out the transfer module.
Note:  Leave the photoconductor units on the transport belt when removing. 
Warning:  To avoid damaging the photoconductor drum, hold the photoconductor units by their handle and 
place the photoconductor units on a clean surface. Never expose the photoconductor units to light for a 
prolonged period of time. See “Handing the photoconductor unit” on page 4-2 for additional 
information.
BC
A 
						

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5.Looking down at the keyed end of the restraint (D), twist the end clockwise, slide the restraint upward 
through the slit (E), and slip the end of the restraint through the keyed hole (F). Repeat for the other side.
DF E 
						

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6.Close the front access door assembly.
7.Remove the two screws (G) that attach the pivot pin to the front access door cover assembly.
8.Remove the bracket (H).
9.Remove the front access cover assembly.
Left cover removal
See “Left cover” on page 7-3 for the part number.
1.Remove the paper tray.
2.Remove the waste toner assembly. See “Waste toner assembly removal” on page 4-176. 
3.Open the front access door.
4.Open the top access door.
5.Remove the two screws (A) on the bottom and one screw higher up (B).
6.Press the locking tab (C).
GH
AB
C 
						

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7.Remove the screws (D) from the rear left cover.
8.Unsnap the right cover from the top cover, then lift and remove the left cover and rear left cover together.
Note:  Because the paper tray dust cover is loose at this point, set it aside.
Note:  If you are removing the left cover to access another part, leave the left cover and the rear left cover 
attached, and you are done. If you need to replace the left cover FRU, continue with the next step to remove the 
separate rear left cover FRU. 
						

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9.Separate the left cover and rear left cover by sliding the left rear cover as shown to disengage the latch (E). 
						

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Operator panel assembly removal (C746)
See operator panel assembly with card on page 7-3 for the part number. 
Warning:  This part might contain customer confidential information. See “Data Security Notice” on page 4-1 
for more details. After removing this part, return it to your next level of support so any data can be 
removed. If the customer requests to keep the part, they must sign a confirmation of memory device 
retention form.
Warning:  When replacing any one of the following components:
•Operator panel assembly
•System board
•Top access cover assembly
Only replace one component at a time. Replace the required component, and perform a POR before 
replacing a second component listed above. If this procedure is not followed, the printer will be 
rendered inoperable. 
1.Remove the top access cover assembly. See “Top access cover assembly removal” on page 4-54.
2.Turn the top access cover assembly over.
3.Remove the eight screws (A) securing the position guide cover.
A