Lexmark 13P0150 - C 750dtn Color Laser Printer User manual

Lexmark™ C750
5060-00x
Lexmark Repair Catalog
The following information is from Lexmark's Service Mnaual.
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U.S.A. P/N 12G9174

Repair information 4-1
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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 pins. 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.

4-2 Service Manual
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Screw identification table
The following table contains screw types, locations, and quantities necessary to service the printer. Pay careful
attention to each screw type location when doing removals. You must install the correct screw type in each
location during reassembly.
Reference
number Screw type Location Purpose Qty
002 4-40 machine Parallel connector to shield Attach 2
102 M3.5x8mm
thread cutting Cartridge guides to upper frame Attach 8
Upper front cover to cartridge guides Attach 4
Front cover pivot to front upper cover Attach 2
Front left light shield to upper front cover Attach 1
121 M3.5x6mm
machine LVPS to lower frame Mounting 7
Right rear cover to LVPS Attach 1
HVPS standoffs to upper frame Attach 4
232 M3x6mm
Taptite metal
thread forming
Ground cable to right front cover support and
upper frame. Attach 2
Ground cable to bottom support plate and engine
card shield Attach 2
Back lamp brackets to fuser frame Attach 2
Front lamp brackets to fuser frame Attach 2
Blank INA covers to RIP shield Mounting 2
RIP card ground shield to RIP shield Mounting 5
RIP shield to engine shield Mounting 4
RIP card to RIP shield Mounting 12
Engine card to engine shield Mounting 6
RIP shield cover to RIP shield Mounting 8
V-block plates to upper frame Mounting 2
Ground cable strap to RIP ground shield Attach 1

Repair information 4-3
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312 M2.9x6mm
Plastite Front access door assembly Mounting 3
Door handle to cover Mounting 2
Detent housing to cover Mounting 1
ITU switch housing to light shield Attach 1
Duplex baffle to lower right door Attach 4
Front and rear latches to lower right door Mounting 2
Bias latch cover to door Attach 1
MPF asm to MPF door Attach 6
Support bracket to MPF door Attach 4
MPF cable cover to door asm Mounting 1
MPF latch support brackets to upper frame Attach 2
Voltage cable to terminal (BOR/ITU) black Attach 1
Voltage cable to terminal (BOR/ITU) cyan Attach 1
Voltage cable to terminal (BOR/ITU) magenta Attach 1
Voltage cable to terminal (BOR/ITU) yellow Attach 1
323 M3.5x1.35mm
Plastite 8 long Frame support back plate to lower frame Attach 2
Door latch catch to frame Attach 2
Transfer HVPS to lower frame Mounting 1
Fuser top duct to lower frame Attach 1
Right front cover support to lower frame Attach 1
Front lower left cover to lower frame Attach 1
Front left handle cover asm to lower frame Attach 4
Front lower right cover to lower frame Attach 1
Front right handle cover asm to lower frame Attach 4
Right front cover to lower frame Attach 2
Left lower cover to lower frame Attach 2
Left upper cover asm to lower frame Attach 2
Left upper cover asm to upper frame Attach 1
Left lower pivot to lower frame Attach 2
Left upper pivot to left lower cover Attach 1
Rear cover to lower frame, left cover Attach 6
Rear fan cover to lower frame and top cover Attach 4
Top cover asm to upper front cover Attach 3
Top cover asm to RIP shield Attach 1
ITU light shield asm to upper front guide ITU Attach 1
Ribs to upper redrive door Mounting 5
Upper door hinges to upper frame (redrive) Mounting 2
Inner redrive asm to upper frame (redrive) Mounting 2
Developer HVPS to cartridge contact asm Mounting 4
Engine card shield to frame Mounting 5
BOR drive asm to upper frame Mounting 1
Reference
number Screw type Location Purpose Qty

4-4 Service Manual
5060-00x
323
(continued) M3.5 x 1.35mm Plastite 8 long
(continued)
ITU drive asm to lower frame Mounting 3
Fuser drive asm to lower frame Mounting 4
Vacuum top duct to lower frame Mounting 2
Toner shield to lower frame Attach 4
Upper deflector to lower frame (PF XPORT) Mounting 2
VTB asm to lower frame
(PF XPORT) Mounting 2
Inner deflector to VTB assembly (PF XPORT) Attach 1
Jam access spring to VTB asm (PF XPORT) Attach 1
500 pick assembly to lower frame Mounting 3
Paper size sensing assembly to lower frame Mounting 1
Paper level sensing assembly to lower frame Mounting 3
324 M3.5x10mm
Plastite thread
forming
Transfer HVPS/RIP fan asm to RIP shield Attach 1
Front left light shield to left upper cover asm and
top cover Attach 1
Front right light shield to right front cover support
and top cover Attach 1
Cartridge drive assemblies to upper frame Mounting 12
Upper door hinges to upper frame (redrive) Attach 2
Inner redrive assembly to upper frame Mounting 2
412 2.9x5.2mm
Plastite Hinge restraint to door (MPF) SEMS Attach 1
423 M3.5x9 Plastite Tray bias bellcrank to tray Mounting 1
484 M3.5x14
Machine
Panhead
Printhead to upper frame Mounting 12
Reference
number Screw type Location Purpose Qty

Repair information 4-5
5060-00x
Removal procedures
CAUTION: Remove the power cord from the printer or 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. The printer weighs 47.7 kg (105 lb) and requires at least
two people to lift it safely. Make sure your fingers are not under the printer when you lift or set the printer down.
Note: 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.
Top cover assembly removal
1. Remove the redrive cap.
2. Remove the right light shield screw type “324” (A) and “323” (B) and release tab (C) from the frame slot.
3. Remove the right light shield.

4-6 Service Manual
5060-00x
4. Remove the operator panel bezel.
5. Remove the top cover mounting screws (D) from the front of the printer.
6. Remove the three top cover screws (E) type “323” on page 4-3 from the rear and the screw (F) from the
left side of the printer.

Repair information 4-7
5060-00x
7. Remove the flag retainer (G) from the top cover.
8. Under the top cover, unclip the bin full sensor (H). Tilt the sensor and lower it through the top cover.
9. Remove the upper option autoconnect (I).
10. Remove the top cover.

4-8 Service Manual
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Rear fancoverremoval
See “Rear fan cover”on page 7-5for the partnumber.
1. Removethe rear cover.See “Rear cover removal”on page4-8.
2. Removethe rear fan cover screwtype “323” (A)and removethe rear fan cover.
Rearcover removal
See “Rear cover” on page 7-5for the partnumber.
1. Remove the rear cover screw type“323” (A).
2. Open the MPF,removethe rear coverscrewtype “323” (B),and remove the rear cover.
A(323) B(323)

Repair information 4-9
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Front right handle cover assembly removal
See “Front right handle cover assembly” on page 7-3 for the part number.
1. Open the front cover.
2. Remove the light shield screw type “324” (A) and screw type “323” (B) and release tab (C) from the frame
slot.
3. Remove the light shield.
4. Remove the front right handle cover assembly screw type “323” (C) and remove the assembly.
C(323)

4-10 Service Manual
5060-00x
Front left handle cover assembly removal
See “Front left handle cover assembly” on page 7-3 for the part number.
1. Open the front cover.
2. Remove the front left handle cover assembly screw type “323” (A) and remove the assembly.
Front cover assembly removal
See “Front cover assembly” on page 7-3 for the part number.
1. Open the front cover.
2. Remove the detent post tension spring (A).
AA(323)
A

Repair information 4-11
5060-00x
3. Remove the bezel (B).
4. Hold the front cover and remove the two screws type “102” (C) from the upper front pivot cover.
5. Remove the front cover assembly.
B
C(102)

4-12 Service Manual
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Lower right door assembly removal
See “Lower right door assembly” on page 7-3 for the part number.
1. Open the lower right door assembly.
2. Remove the front right handle cover assembly. See “Front right handle cover assembly removal” on
page 4-9.
3. Remove the screw (A) on the lower right front cover.
4. Close the paper path access door and tape front jam access door (B) if tape is available, to help hold the
door in place.
The spring loaded door is difficult to reassemble. Avoid disassembly of the door, unless you need to
replace the paper path access door.

Repair information 4-13
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5. Loosen the two screws (C).
6. Remove the lower right door assembly.
Left lower cover removal
1. Remove the lower jam access door assembly. See “Lower jam access door assembly removal” on
page 4-14.
2. Remove the left lower cover screw type “323” (A) and remove the cover.
A(323)

4-14 Service Manual
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Lower jam access door assembly removal
See “Cover, left lower” on page 7-5 for the part number.
1. Remove the front left handle cover assembly. See “Front left handle cover assembly removal” on
page 4-10.
2. Remove the lower jam access door assembly screw type “323” (A) and remove the door.
Redrive door removal
See “Redrive door” on page 7-16 for the part number.
1. Open the redrive door.
2. Loosen the redrive door upper hinge screw type “324” (A).
3. Lift the redrive door from the hinge (B) and remove the redrive door.
A(323)
A(324) B

Repair information 4-15
5060-00x
Paper path access door cover removal
See “Paper path access door” on page 7-3 for part number.
1. Remove the paper tray.
2. Remove the front left handle cover assembly. See “Front left handle cover assembly removal” on
page 4-10.
3. Open the paper path access door, carefully remove screw (A) type “323” on page 4-3,
and remove the door.
4. Remove the front lower left cover and door.
Do not lose the spring.

4-16 Service Manual
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Front lower left cover removal
See “Front lower left cover” on page 7-3 for part number.
1. Remove the paper tray.
2. Remove the front left handle cover assembly. See “Front left handle cover assembly removal” on
page 4-10.
3. Open the paper path access door, carefully remove screw (A) type “323” on page 4-3,
and close the door.
4. Close the paper path access door and tape front jam access door (B) if tape is available, to help hold the
door in place.
The spring loaded door is difficult to reassemble. Avoid disassembly of the door, unless you need to
replace the paper path access door.
5. Remove the front lower left cover with the paper path door attached.

Repair information 4-17
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Autocompensator pick assembly removal
1. Remove all cartridges.
2. Remove the ITU. See “ITU assembly removal” on page 4-37.
3. Remove tray 1.
4. Remove the second transfer roll. See “Second transfer roll removal” on page 4-79.
5. Remove the transfer plate. Lifting and rotating the right edge of the plate up to a 45° angle will release the
transfer plate. Remove the grounding strap (A) attached to the bottom of the transfer plate.
6. Remove the black mylar piece by removing the two screws (B) or cutting the cable tie.
B

4-18 Service Manual
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7. Remove the five screws “323” (C) and remove the lower left cover and the jam access door.
Warning: Be careful not to lose the access door spring.
8. Remove the pin (D) that holds in the MPF swing arm assembly.
C(323)
D

Repair information 4-19
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9. Remove the MPF swing arm assembly (E).
E