Printer removals. Lexmark C746dn, C748e, C748de, C748dte, C746DTN, C746N

Remove the EP drive assembly. See

“Electrophotographic (EP) drive assembly removal” on page 4-90

Disconnect the connector at JINT1 (A) on the system board.

5026

Go Back

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Open the front access door cover, and remove the screw (B).

Go Back

Remove the cable from the two cable retainers (C).

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Service Manual

Remove the 5 V interlock switch and bracket from the printer.

Remove the screw (D), and remove the 5 V interlock switch cable from the bracket.

5026

Go Back

24 V interlock switch removal

See

“24 V interlock switch” on page 7-9

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the connector at JCVR1 (A) at system board.

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Remove the screw (B), and the bracket separates from the 24 V interlock switch.

Go Back

Installation notes:

Observe the routing of the 24 V interlock switch cable (C).

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Service Manual

5026

Bin full sensor flag removal

Remove the top access cover assembly. See

“Top access cover assembly removal” on page 4-54

Turn the top access cover over, and use a flatblade screwdriver to carefully remove the flag (A).

Go Back

Bin full sensor removal

See

“Bin full sensor with cable” on page 7-3

for the part number.

Remove the top access cover assembly. See

“Top access cover assembly removal” on page 4-54

Turn the top access cover over, and press the side of the bin full sensor (A) to snap it loose from the cover.

Remove the bin full sensor and cable.

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Cartridge cooling fan removal

Remove the top cover. See

Turn the top cover over, and remove the two screws (A).

Remove the cartridge cooling fan.

Go Back

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Service Manual

Cartridge motor 1/fuser cable removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the connectors in JCARTP1 (A) and JCARTS1 (B) on the system board.

5026

Go Back

Disconnect the connectors from the cartridge motor 1 (C) and the fuser motor (D).

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Disconnect the camshaft cable connector (E) from the motor card, and unwind the two cables.

Go Back

Remove the cable from the six retainers (F).

Installation notes:

•

Make sure you wrap the camshaft cable around the cartridge motor 1/fuser cable, as shown, to prevent the cables from interfering with the motors and damaging the cables.

•

Note the routing of the cables and the cable retainers.

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Service Manual

Cartridge motor 2/3 cable removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the connectors in JCARTP2 (A) and JCARTS2 (B) on the system board.

5026

Go Back

Disconnect the connectors from the cartridge motor 2 (C) and cartridge motor 3 (D).

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Remove the cable from the six retainers (E).

Installation note:

Pay attention to the routing of the cables and the cable retainers.

Color on demand assembly removal

Remove the fuser. See

“Fuser removal” on page 4-110

Remove the print cartridges.

Remove the top cover assembly. See

Disconnect the connector at JBOR1 (A) on the system board.

Go Back

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Service Manual

Remove the five screws (B).

Remove the COD assembly.

5026

Go Back

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Installation notes:

Push the actuators (A) all the way down.

Turn the printer around, and verify the actuators are in the correct location by looking inside the front of the printer. The actuators (B) should be visible in the triangular holes in the frame, as shown.

Go Back

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Rotate the large COD gear until the stop (C) on the gear is against the housing.

5026

Go Back

Engage the gears on the left side of the COD.

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Engage the gears (D) on the right side of the COD.

Replace the five screws (E).

Verify the actuators can be seen by looking inside the printer at the triangular holes, as in step 2.

Check to make sure you can rotate the large COD gear from stop to stop.

Go Back

Reconnect the cable connector to JBOR1 connector on the system board.

10.

Reinstall the top cover assembly, the fuser, and the covers.

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5026

Contact springs kit removal

See

page 7-13

Toner cartridge contacts removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Remove the printhead. See

“Printhead removal, installation, and adjustment” on page 4-145

Remove contact spring cables from the cable restraints (A).

Note:

Pay attention to the routing of the cartridge contact cables, and the appropriate slots where each cartridge contact is installed.

Go Back

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Remove the three screws (B) securing the top three bell crank links.

Go Back

Remove the bell crank link (C) together with its bell crank spring (D).

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C D

5026

Installation notes: a.

When installing the bell crank link and spring back to the machine, guide the mounting hole on the bell crank link to the mounting pin on the cartridge guide (E), and guide one end of the spring onto the boss rest on the bell crank link and the other end onto the boss rest on the bell crank (F).

Make sure the locator pin on the bell crank rests on the locator hole of the bell crank link (G).

Go Back

F E F G

Use a prying tool to remove the bell crank.

Note:

The bell crank must be replaced due to the damage that can occur to the retention features of this bell crank.

Perform steps 5 and 6 to the other bell crank links and bell cranks, except for the one found at the lowermost portion of the cartridge guide.

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Remove the lower-most bell crank spring (H) and bell crank (I).

Go Back

H I

Using a spring compression tool (J), align its opening to the rib on the cartridge guide as shown, then push and hold the spring compression tool into the cartridge contact spring.

Note:

Make sure to properly align the opening on the spring compression tool to the rib on the cartridge guide.

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10.

Remove the cartridge contacts from the right side of the machine, then release the spring compression tool.

Note:

Pay attention to the color coding of the cartridge contact cables, and the appropriate slots where each cartridge contact is installed.

Go Back

Installation notes: a.

Insert the cartridge contact spring into the slot on the cartridge guide.

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Position the spring compression tool (K) as shown below and align its opening to the rib on the cartridge guide, then push and hold the spring compression tool into the cartridge contact spring.

Note:

Make sure to properly align the opening on the spring compression tool to the rib on the cartridge guide.

Go Back

Insert the cartridge contact on the right side of the machine.

11.

Perform steps 9 and10 to remove all the cartridge contacts.

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5026

Charge roll contact spring removal

Remove the HVPS. See

“High-voltage power supply (HVPS) removal” on page 4-115

Remove the charge roll contact springs (A). Be sure to push the springs under the retainers that hold them in place.

Installation note:

Make sure the springs are behind the retainers when installing the new springs.

Retainer

Go Back

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HVPS contact springs removal

Remove the HVPS. See

“High-voltage power supply (HVPS) removal” on page 4-115

Pull out the spring that will be replaced:

•

HVPS DB contact spring (A)

•

HVPS DR contact spring (B)

•

HVPS TAR contact spring (C)

Go Back

Installation note:

Refer below for the location of the HVPS DR Contact spring and HVPS DB contact spring.

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Service Manual

27S1997 HVPS DR Contact

27S1998 HVPS DB Contact

Torsion spring removal

Open the front access door and remove all the toner cartridges.

Remove the screw (A) and the spring cap (B) of the appropriate contact spring.

5026

Go Back

A B

Press the lower half (C, D) of the springs, and remove the springs.

C D

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Installation notes:

When installing, make sure the top half (E) of the spring is under the straight spring (F). This is typical for both types of springs. Also make sure the bottom half (D,G) of both springs are compressed and locked by the appropriate locking tabs (H, I).

F E

Go Back

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Service Manual

Cooling fan removal

Remove the rear upper cover. See

Remove the rear frame cover. See

Disconnect JFAN1 (A).

5026

Go Back

Remove the two screws (B).

Remove the cooling fan.

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5026

Cooling fan filter removal

Remove the rear upper cover. See

Turn the cover over.

Squeeze the right side of the filter, and remove it from the tabs (A).

Go Back

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Service Manual

5026

Duplex reference edge guide assembly removal

Remove the paper tray.

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access door cover assembly.

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

for additional

information.

Go Back

B C

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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.

Go Back

D F E

Close the front access door assembly.

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5026

Remove the two screws on the duplex aligner (G), and then remove the screw (H) securing the duplex reference edge guide assembly.

Go Back

H G

Remove the duplex reference edge guide assembly.

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5026

Electrophotographic (EP) drive assembly removal

See

“EP drive assembly” on page 7-9

“Transfer module removal” on page 4-171

Remove the paper tray.

Remove the transport belt module and the developer units. See

Remove the cartridges.

Remove the low-voltage power supply (LVPS). See

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the cartridge 1/fuser motor cable (two connectors) (A), and remove the cables from the cable retainers (B).

Go Back

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5026

Disconnect the camshaft/transport cable connector (C), and remove the cable from the cable clamps (D).

Go Back

Unwind the camshaft/transport cable and the cartridge 1/fuser cables (E).

Note:

Be sure to rewind the camshaft/transport cable around the other cables with about four twists to keep them from interfering with or being damaged by the motors.

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Disconnect the cartridge 2/cartridge 3 motor cable (two connectors) (F), and remove the cable from the cable clamps (G).

Go Back

Disconnect the motor drive cable connector (H), and remove the cable from the cable clamps (J).

10.

Remove the two screws (K) to remove the motor driver card assembly.

H J

11.

Remove the two screws (L) on the inside

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Service Manual

12.

Remove the three screws (M) on the front.

5026

Go Back

L M

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13.

Remove the seven screws (N) securing the EP drive.

Go Back

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Service Manual

N (First)

14.

Remove the 5 V interlock switch cable from the restraint (N) on the backside of the EP drive.

5026

Go Back

15.

Remove the EP drive.

Installation notes:

Push the actuator rack all the way to the right (A).

Pull the link all the way up (B).

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5026

Fasten the 5 V interlock cable into the cable retainer (C) on the bottom of the EP drive.

Go Back

Align the gear so the first gear tooth (D) of the top cover camshaft meshes with the first two gear teeth (E) after the flat area in the EP drive actuator rack, and then seat the right side of the top cover camshaft into the boss (F) on the EP drive.

Flat area

(gap)

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5026

Hold the drive in place while replacing the first of the seven screws, then continue replacing the rest of the screws (G).

Go Back

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Replace the two screws (H) from the inside.

Replace the three screws (J) on front.

Wind the camshaft cable (K) around the cartridge 1/fuser cables about four times to make sure they do not interfere with or are damaged by the fuser motor.

Connect the cartridge 1/fuser motor cable (two connectors) (L), and place the cables in the cable retainers (M).

Go Back

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5026

10.

Connect the cartridge 2/cartridge 3 motor cable (two connectors) (N), and make sure the cable is in the cable clamps (O).

Go Back

O N

11.

Hold the motor driver card in place and reinstall the two screws (P) to secure the motor driver card.

12.

Connect the three connectors (Q), and secure the cables in the cable clamps (R).

P R

13.

Reinstall the low-voltage power supply (LVPS).

14.

Replace the right and rear covers.

15.

Replace the transport belt module and developer units.

16.

Replace the cartridges and the fuser.

17.

Replace the paper tray.

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Front door assembly removal

See the part number for the Front door assembly for the specific model you need on

page 7-7

Remove the front access cover assembly. See

“Front access cover assembly removal” on page 4-29

Remove the rear frame cover. See

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the JTPS1 cable (A) from the system board.

Go Back

Release the left and right front door assembly cable springs (B) from the front door assembly.

B B

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Service Manual

Open the front door assembly.

Unwrap and remove the cable from the left and right pulleys (C).

5026

Go Back

Close the front door assembly, and remove the mounting screw (D) and the cap (E).

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Open the front door assembly, slide it to the right, and remove. You need to press firmly to slide the front door assembly to the right.

Go Back

Installation note:

See

“Front door assembly front cable (left) removal” on page 4-103

and

“The longer cable installs on the left side of the printer.” on page 4-106

for proper installation of the cable restraints.

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5026

Front door assembly front cable (left) removal

Remove the paper tray.

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access door cover assembly.

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:

for additional

information.

Go Back

B C

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Go Back

D F E

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Service Manual

Remove the fuser. See

“Fuser removal” on page 4-110

Push down on both of the front door locking mechanism simultaneously to close the camshaft.

5026

Go Back

Close the front access door assembly.

Release the cable spring (H) from the front door assembly.

Note:

In order to access the springs, make sure the top access cover is closed.

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10.

Remove the end of the cable (J) from the frame.

Installation notes:

•

The longer cable installs on the left side of the printer.

•

Push down on the lever to raise front door locking mechanism and open the camshaft.

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Service Manual

Go Back

5026

Front door assembly front cable (right) removal

Remove the paper tray.

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access door cover assembly.

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:

for additional

information.

Go Back

B C

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Go Back

D F E

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Service Manual

Remove the right cover. See

“Fuser assembly, 115 V” on page 7-7

Close the front access door assembly.

Release the spring (G) from the front door assembly.

Note:

In order to access the springs, make sure the top access cover is closed.

5026

Go Back

Remove the end of the cable (H) from the frame.

10.

Remove the right restraint cable.

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Installation note:

The shorter restraint cable installs on the right side of the printer.

Note:

The frame end needs to be wrapped to inside of post for two full turns

Go Back

Fuser removal

See

“Fuser assembly, 230 V” on page 7-7

, or

“Fuser assembly,

100 V” on page 7-7

for the part number.

CAUTION

The fuser can be extremely hot. Use care when handling to avoid burns.

Turn off the printer.

Open the front access door.

Open the top access door.

Rotate the fuser thumbscrews (A) counterclockwise until loosened.

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Service Manual

Grasp the handles (B), slide the fuser out from the printer.

5026

Go Back

Installation note:

If you install a new fuser, be sure to reset the fuser counter in the Configuration Menu, and run the Motor Calibration. To reset the counter and run the calibration:

Enter the Configuration Menu. (Turn off the printer, press and hold buttons 2 and 6, turn on the printer, and release the buttons when the progress bar displays.)

Press for the Reset value.

Resetting Fuser Count Value appears.

Select Motor Calibration from the CONFIG MENU.

Calibrating displays, and the printer prints several blank pages and then returns to the CONFIG MENU.

Select Exit Config Menu.

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Fuser AC cable removal

Note:

The LVPS to fuser AC cable is black.

Remove the top cover assembly. See

Turn the top cover assembly over.

Lift the locking latch (A) on the connector, slide the connector down, and remove the connector from the keyed hole.

Go Back

Remove the cable from the cable openings (B).

Note:

Observe the routing of the cable for reinstallation.

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Service Manual

Fuser DC cable removal

Note:

The fuser to system board autoconnect cable is red.

Remove the top cover assembly. See

“Data Security Notice” on page 4-1

Turn the top cover assembly over.

Remove the connector (A) from the top cover assembly.

Warning:

You will damage the old connector in the process. Be careful not to damage the top cover assembly.

Pull the cable through the hole (B) in the top cover assembly, and the notch (C).

5026

Go Back

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Hard drive assembly removal

Warning:

This part might contain customer confidential information. See

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.

Remove the rear frame cover. See

“High-voltage power supply” on page 7-13

Remove the two screws (A), and squeeze the connector to disconnect the hard disk from the system board (B).

Go Back

Pull the hard disk straight out to pop the hard drive standoffs free of the system board.

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High-voltage power supply (HVPS) removal

See

for the part number.

Remove the left cover. See

Remove the six mounting screws (A).

5026

Go Back

Release the locking tab (B) from the front, lower corner of the HVPS.

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Disconnect the five connectors (C) from the HVPS.

Installation notes:

•

Make sure to replace the spring when replacing the HVPS.

•

There are two types of spring forces on the cartridge contacts. Make sure to put the springs in their appropriate slots and are oriented properly.

Go Back

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Service Manual

High-voltage power supply (HVPS) cable removal

Remove the rear upper cover. See

“Left bellcrank assembly, with spring” on page 7-7

Disconnect the cable connector at JHVPS1 on the system board.

5026

Go Back

Disconnect the cable connector (B) from the HVPS.

Remove the cable from the hole through the frame (C), and from the two cable restraints (D).

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Left bell crank assembly removal

See

Remove the left cover. See

“Low-voltage power supply” on page 7-9

Remove the C-clip (A).

Go Back

Remove the left bell crank assembly.

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Service Manual

Low-voltage power supply (LVPS) removal

See

Remove the right cover. See

Remove the rear frame cover. See

Disconnect the connector at JLVPS1 connector (A) on the system board.

5026

Go Back

Remove the five LVPS mounting screws (B).

Disconnect the AC fuser cable (C) from the LVPS.

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Installation note:

•

When installing the new LVPS, make sure the voltage switch (A) is set for the proper value (115 V or

230 V), depending on the country.

Note:

Not all LVPS FRUs have a switch. Others are switched automatically.

Go Back

•

Install the LVPS, and make sure the AC fuser cable is in the cable guides, and not behind the LVPS.

•

Reconnect the AC fuser cable to the LVPS.

•

Replace the five LVPS mounting screws.

•

Reconnect the cable in connector JLVPS1 on the system board.

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Motor driver card removal

Remove the right cover. See

Disconnect the three cables (A).

Remove the two screws (B), and remove the motor driver card.

5026

Go Back

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Motor driver cable removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the connector in JDVR1 (A) on the system board.

Go Back

Disconnect the connector on the motor driver card (B).

Remove the cable from the cable from the four cable retainers (C).

Installation note:

Pay attention to the routing of the cable and the cable retainers.

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Multipurpose feeder (MPF)/duplex gear and housing removal

See the multipurpose feeder/duplex gear and housing kit for the part number.

Remove the paper pick mechanism assembly. See

“Paper pick mechanism assembly removal” on page 4-137

Remove the two E-clips (A) from the gears.

Go Back

Remove the three screws (B).

Slide the front gear (C) off.

B C

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Slide a flathead screwdriver up and under the front cover.

Slide the remaining two gears and housings off.

Go Back

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5026

Multipurpose feeder (MPF)/duplex motor assembly removal

See

“MP feeder/duplex drive parts packet” on page 7-7

for the part number.

Remove the low-voltage power supply (LVPS). See

“Low-voltage power supply (LVPS) removal” on page 4-119

Remove the multipurpose feeder/duplex gear and housing. See

“Multipurpose feeder (MPF)/duplex gear and housing removal” on page 4-123

Remove the two multipurpose feeder/duplex motor mounting screws (A).

Go Back

Remove the multipurpose/duplex motor from the printer.

Push in the prongs (B) of the housing to remove the cable tie (C).

Slide the motor out of the housing.

Disconnect the connector (D) from the motor.

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Installation notes:

Connect the cable (A) at the motor.

Slide the cable tie (B) onto the motor.

Go Back

Insert the motor into the frame.

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Service Manual

Replace the screws (C).

Slide the housing onto the motor, making sure the four tabs of the housing slide under the cable tie.

5026

Go Back

Replace the multipurpose feeder/duplex gear and housing assembly.

Repair information

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Multipurpose feeder (MPF)/duplex motor cable removal

Remove the multipurpose feeder/duplex motor. See

“Multipurpose feeder (MPF)/duplex motor assembly removal” on page 4-125

Disconnect the connector from JDX1 (A) on the system board.

Go Back

Remove the cable from the cable retainers (B).

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Multipurpose feeder (MPF) paper present sensor

Remove the right cover. See

Remove the standard 550-sheet input tray.

Remove the rear frame cover. See

“Low-voltage power supply (LVPS) removal” on page 4-119

Remove the Low-voltage power supply (LVPS). See

Remove the three screws (A) securing the tray rail that contains the paper present sensor.

Go Back

Remove the JMPFPP1 connector (B) from the system board, then remove the cable.

Installation note:

Pay attention to the routing of the cable.

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Remove the MPF paper sensor bracket from the machine.

Go Back

Pry the sensor off the bracket, then disconnect the sensor (C) from the cable (D).

Remove the cable from the bracket.

Installation note:

Pay attention to the routing of the cable.

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MPF pick removal

Open the MPF door.

Press the latch on the MPF pick then pull to the left to remove.

Repair information

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5026

Go Back

5026

Operator panel cable removal

Remove the top access cover assembly. See

“Top access cover assembly removal” on page 4-54

Turn the top access cover assembly over.

Remove the eight screws (A), and remove the position guide cover.

Go Back

Pull open the operator panel connector (B) and disconnect the operator panel cable from the operator panel card.

Remove the operator panel cable from the toroid (C) and the two cable retainers (D).

D C B

Installation note:

Make sure the contact pins on the cable are facing up when reconnecting the operator panel cable to the connector.

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Operator panel ground cable removal

Remove the top access cover assembly. See

“Top access cover assembly removal” on page 4-54

Turn the top access cover assembly over.

Remove the eight screws (A) securing the position guide cover.

Go Back

Disconnect the operator panel ground cable from the operator panel ground pin (B).

Remove the screw (C) securing the operator panel ground cable to the operator panel card.

B C

Remove the operator panel ground cable from its retainers.

Installation note:

Pay attention to the routing of the ground cable.

Repair information

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Operator panel USB connector cable removal

Remove the top access cover assembly. See

“Top access cover assembly removal” on page 4-54

Turn the top access cover assembly over.

Remove the eight screws (A) securing the position guide cover.

Go Back

Disconnect the USB ground cable (B) and detach the USB cable connector (C) from the USB slot.

Remove the USB cable and ground cable from its retainers.

Installation note:

Make sure to observe the routing of the USB cable.

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Option cable removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Disconnect the cable connector at JOPT1 (A) on the system board.

5026

Go Back

Replace the rear frame cover to protect the system board.

Position the printer on its back.

Remove the two screws (B).

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Press the tabs together to remove the option cable connector.

Note:

Be sure to note the cable routing for reinstallation.

Go Back

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Service Manual

Paper pick mechanism assembly removal

See

“Paper pick assembly” on page 7-7

“Waste toner assembly removal” on page 4-176

Remove the paper tray.

Remove the waste toner assembly. See

Remove the rear frame cover. See

“Waste toner assembly removal” on page 4-176

Disconnect the connector in JFDPCK1 (A) and JTRAY1 (B) on the system board.

Push the cables through the hole in the frame (C).

5026

Go Back

Open the front access cover.

Repair information

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5026

Remove the transfer module with the photoconductor units attached.

Disconnect the transfer module cable (D).

Press the two tabs (E) to release the front access cover assembly, and lower the front access door cover.

Press the two tabs (F) 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, place the transfer module with the photoconductor units on a clean surface. Never expose the photoconductor units to light for a prolonged period of time. Place a clean, dry cloth over the transfer module and photoconductor units until they are required.

Go Back

E F

Remove the toner cartridges.

Warning:

Do not touch the developer rolls.

Remove the four screws (G) from the bottom pan.

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Service Manual

10.

With one hand, disengage the gear (H), then grasp the paper pick assembly, and pull forward and downward to disengage the assembly until the front (J) and rear locking tabs release (not visible).

5026

Go Back

11.

Lower the paper pick mechanism, and remove through the front of the printer.

Note:

Make sure the JTRAY1 and JTRAY2 connectors do not bind when passing through the frame access hole.

Installation notes:

Remove the waste toner assembly. See

Replace the rear frame cover to protect the system board.

Turn the printer on its back.

Slide the paper pick assembly toward the back of the printer, and down to engage the tabs (A).

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Engage the gear (B).

Go Back

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Reach into the printer, and replace the front right screw (C) to secure the paper pick assembly.

Set the printer upright.

Secure the remaining three screws (D).

5026

Go Back

Remove the rear frame cover.

10.

Route the cables through the hole in the frame, and connect them to JFDPCK1 (E) and JTRAY1 (F).

11.

Replace the rear frame cover.

12.

Replace the waste toner assembly.

13.

Replace the toner cartridges.

14.

Replace the transfer module with the photoconductor units.

15.

Close the front access cover.

16.

Replace the paper tray.

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Photoconductor unit removal

Not a FRU

Warning:

To avoid damaging the photoconductor drum, hold the photoconductor units by their handle and place the photoconductor units on a clean surface. See

for additional information.

Open the front access door.

Lift the right end handle (A) of the photoconductor unit, releasing from the mount.

Lift the unit up and away from the left side of printer, ensuring the left end of the photoconductor is released from the holding pin (B).

Go Back

Installation note:

If a new photoconductor unit is installed, reset the life count value in the printer memory.

•

If a message appears on the operator panel:

When

84 <color> PC Unit Life Warning or 84 Replace <color> PC Unit appears, select Supply

Replaced

, and then press .

Replace Supply displays.

Select Cyan PC Unit, Magenta PC Unit, Yellow PC Unit, or Black PC Unit based on the photoconductor unit that was just replaced, and then press .

<color> PC Unit Replaced displays.

Select Yes, and then press to clear the message.

•

If no message appears:

Press Menu ( ).

Select Supplies Menu, and press .

Press select .

Select Cyan PC Unit, Magenta PC Unit, Yellow PC Unit, or Black PC Unit based on the photoconductor unit that was just replaced, and then press .

<color> PC Unit Replaced displays.

Press

Yes

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Pick arm roll removal and replacement

See

“Pick arm roll” on page 7-7

“Printhead assembly” on page 7-11

The auto compensator pick roll tires are located in the base printer. There are also tires in all input options. If you have additional input options, and you are having problems with media picking, replace these tires also. Always replace the pick arm rolls in pairs. The rolls come in a package of two.

Warning:

Remove only the rubber tires and not the pick tire assembly to avoid losing small parts.

Remove the paper tray.

Pull the paper pick arm (A) down.

Go Back

Remove the pick arm roll (B) from the pick arm roll assembly (C). Repeat for the other pick arm roll (D).

B C D

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Installation notes:

Install the new rubber tires with the surface texture turning in the direction as shown.

Note:

Feel the rubber surface to verify it turns properly in the direction shown.

Go Back

Printer pad removal

Slide the corner of the printer containing the damaged pad over the corner of the table.

Remove the side cover that corresponds to the damaged pad so you can see if the pad fully seats in the installation holes.

Pull the pad tabs (A) from the bottom of the printer.

Installation note:

Verify that the pad fully seats in the installation holes.

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Printhead removal, installation, and adjustment

See

“Printhead verification” on page 3-39

Service tip—Testing the new printhead

See

for quick way to verify that the existing printhead is failing

before installing the new printhead. If the new printhead also fails, the existing printhead is probably working properly, so the system board is probably the failing component.

Printhead removal

Turn the printer off.

Disconnect the power cord from the electrical outlet and from the printer.

Remove the paper tray.

Open the front access door.

Open the top access door.

Remove the fuser.

Go Back

Remove the transfer module and photoconductor units.

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access cover assembly.

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.

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Warning:

To avoid damaging the photoconductor drum, place the transfer module with the photoconductor units on a clean surface. Never expose the photoconductor units to light for a prolonged period of time. Place a clean, dry cloth over the transfer module and photoconductor units until they are required.

Go Back

B C

Remove all of the toner cartridges.

Remove the right cover and the right side cover (attached). See

10.

“Low-voltage power supply (LVPS) removal” on page 4-119

11.

Remove the system board support shield. See

“System board support shield removal” on page 4-160

12.

Push the top access cover down until it clicks into place.

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13.

Remove the three printhead mounting screws (D).

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Go Back

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14.

Remove the printhead alignment screw cover (E).

15.

While still holding the printhead in place, loosen the printhead alignment screw (F) until the printhead comes out.

Warning:

Secure the printhead when loosening the printhead alignment screw. Failure to do this allows the printhead to fall out of the printer, potentially damaging the printhead.

Go Back

Install the printhead and replace parts

Warning:

•

When reinstalling the printhead, it is important to keep in mind that the printhead mounting screws should be initially tightened just enough to hold the printhead in the printer. The printer parts are installed with the printhead mounting screws loose so you can print the pages that will be used to align the black plane to the printer frame. This also allows the black skew adjustment to be adjusted with the printhead alignment screw.

•

Once the black skew is aligned, the mounting screws will be fully tightened, and the next steps of alignment can be completed.

When installing the printhead, visually center the printhead and center the hole in the frame (A).

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Loosely attach the three printhead mounting screws (B).

Warning:

Do not fully tighten the printhead mounting screws until skew has been adjusted.

5026

Go Back

Lightly tighten the alignment screw (C).

Feed the ground cable through the hole in bottom leftside frame.

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Replace the system board support shield screws (E):

Loosely attach the two mounting screws (E2)

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.

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.

Go Back

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Replace the system board.

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.

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).

Go Back

F3 F1

F3 F1 F3 F4 F1

Route the cables through the access holes on the right side of the printer.

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5026 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.

Go Back

Reconnect all the cables to the system board. Use the diagram below as a guideline.

Warning:

Be careful in 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.

Install the hard disk if appropriate.

Replace the LVPS.

Install the LVPS, and make sure the cable is in the cable guides, and not behind the LVPS.

Reconnect the cable to the LVPS.

Replace the five LVPS mounting screws.

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5026 d.

Reconnect the cable in connector JLVPS1 on the system board.

Replace the right cover.

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.

Replace the screw at the bottom of the rear frame cover.

Replace the two screws securing the right cover at the bottom.

Replace the metal screw at the bottom on the inside front cover

Replace the plastic screw at the top on the inside of the front cover.

Replace the left cover, the rear left cover, and the paper tray dust cover.

Place the paper tray dust cover into position.

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.

Replace the taptite screw on the rear frame cover.

Replace the three screws on the left cover.

10.

Replace the rear frame cover.

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.

Align the printhead

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.

Plug the electrical cord into the printer.

Plug the electrical cord into the outlet.

Align the printhead skew for black. Go through steps 13 to 18 on

page 4-10

for printhead alignment skew

for black on the C746 model, or go through steps 13 to 18 on

page 4-19

for printhead alignment skew for

black on the C748 model

Perform top margin alignment for black. Go to

page 4-13

for top margin alignment for black on the C746

model, or go to

page 4-23

for top margin alignment for black on the C748 model.

Perform bottom margin alignment for black. Go to

page 4-13

for bottom margin alignment for black on the

C746 model, or go to

page 4-23

for bottom margin alignment for black on the C748 model.

Perform left margin alignment for black. Go to

page 4-14

for left margin alignment for black on the C746 model, or go to

page 4-24

for left margin alignment for black on the C748 model.

Perform right margin alignment for black. Go to

page 4-14

for right margin alignment for black on the C746 model, or go to

page 4-24

for right margin alignment for black on the C748 model.

Perform alignment for cyan, yellow, and magenta. Go to

page 4-14

for cyan, yellow, and magenta

alignment on the C746 model, or go to

page 4-24

for cyan, yellow, and magenta alignment on the C748 model.

Go Back

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Right bell crank assembly removal

See

“Right bellcrank assembly, with spring” on page 7-7

Remove the right cover. See

Remove the C-clip (A).

Go Back

Remove the right bell crank assembly.

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Speaker removal

See

“Speaker” on page 7-5

for the part number.

Remove the rear upper cover. See

Remove the right cover. See

customer confidential information. See

Disconnect the speaker connector (A).

Loosen the three screws (B), then remove the speaker.

5026

Go Back

B A

System board removal

Warning:

See the system board part number for the model you need on

page 7-11

. This part might contain

CAUTION

This product contains a lithium battery. THERE IS A RISK OF EXPLOSION IF THE BATTERY

IS REPLACED BY AN INCORRECT TYPE. Discard used batteries according to the battery manufacturer’s instructions and local regulations.

“Data Security Notice” on page 4-1

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.

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Warning:

Be careful not to damage the printhead cable when removing the system board.

Remove the left cover and the rear left cover. See

Remove the rear frame cover. See

“Hard drive assembly removal” on page 4-114

Remove the hard disk if one is installed. See

Remove all the screws (A) from the left side of the printer so you can remove the system board, including:

•

USB port connector (1 screw)

•

Ethernet port connector (1 screws)

•

Modem shield (1 screws)

•

Hard disk shield (2 screws)

•

Ground screw (1 screw)

Go Back

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Disconnect all the cables from the system board.

Warning:

Do not use tools to remove the printhead ribbon cable (B). A flat ribbon cable can be damaged and should be removed gently by hand.

Go Back

Remove the nine screws (C) from the system board.

Remove the system board.

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Installation notes:

Place the system board in position.

Note:

Check that the mirror motor cable and the printhead cable do not rub against the edges of the frame.

Replace the nine screws (A) in the system board in the following order:

•

Loosely attach the four corners (A1) in a clockwise order, beginning with the left top corner.

•

Replace the USB connector screw (A2).

•

Replace the top center, right center side, and left center side (A3).

•

Tighten the top left corner and top right corner.

•

Replace the two screws on the center bottom (A4).

•

Tighten the bottom right and bottom left corners (A1).

A3 A1

Go Back

A3 A1 A3 A4 A1

Route the cables through the access holes on the right side of the printer.

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Replace all the screws (B) 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 (C) to the ground screw.

5026

Go Back

Reconnect all the cables to the system board. Use the diagram below as a guideline.

Warning:

Be careful reconnecting the printhead ribbon cable (D). It can be damaged and should be handled carefully. A flat ribbon cable can easily be damaged and should be connected gently by hand.

Install the hard disk if appropriate.

Replace the rear frame cover and the left cover.

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System board support shield removal

See

“System board support shield” on page 7-11

“System board removal” on page 4-155

Remove the system board. See

Remove the right cover. See

“Toner level sensor” on page 7-13

Pull the cables through the access holes on the right side of the printer.

Remove the five mounting screws (A) from the outer left side of the printer.

Note:

Make a note of the attachment of the printhead ground cable (B) to the fourth screw from the top for later installation.

Remove the four screws (C) from the inner right side of the support shield.

Go Back

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Remove the five mounting screws (D) from the top and bottom of the support shield.

Note:

Only the ribbon and mirror motor cables come through the access holes in the system board support shield.

5026

Go Back

Lower and remove the support shield. Be careful not to damage the ribbon cable that routes through the bottom frame of the printer.

Installation notes:

Loosely attach the two mounting screws (A).

Set the system board support shield in place.

Note:

Check that the ribbon mirror motor cable (white) and the printhead cable (bottom) do not rub against the edges of the frame.

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Replace the remaining system board support shield screws in the following order:

•

Replace the four screws (B) from the inner right side of the support shield.

•

Tighten the two mounting screws (A) to the top of the support shield.

•

Replace the three screws (C) from the bottom of the support shield, and two screws from the top.

•

Replace the five mounting screws (D) to the outer left side of the printer.

Note:

Be sure to connect the printhead ground cable (E) to the fourth screw from the top.

Go Back

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Toner level sensor removal

See

for the part number.

Note the locations of the toner sensors.

5026

Go Back

Remove the HVPS. See

“High-voltage power supply (HVPS) removal” on page 4-115

For the upper two sensors:

These sensors are more difficult to reach because the toner is difficult to reach:

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It is difficult to press both locking tabs at the same time. Using a spring hook, press the locking tab (A), and disengage the sensor on that side. Press the other locking tab (B), and remove the sensor.

Note:

Use a slight pressure on the cable to keep the first locking tab from relatching, while you disconnect the second locking tab.

Go Back

For the lower two sensors:

Using a spring hook, press the locking tab (C), and disengage the sensor on that side. Press the other locking tab (D), and remove the sensor.

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Top cover camshaft assembly removal

See

“Top cover camshaft assembly” on page 7-14

Open the front cover access door cover.

Open the top access cover.

Remove the two screws (A) from the links on either side, and disengage the links.

5026

Go Back

Rotate the top access cover back, and place a screwdriver in the cable hole in the frame to hold the cover in place.

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Remove the fuser. See

“Fuser removal” on page 4-110

Remove the top screw (B), and loosen the other screw (C). This will allow you to flex the EP drive.

Go Back

Remove the two screws (D).

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Rotate the camshaft up using the camshaft actuator handles (E) so you can access the other two screws (F), and remove them.

5026

Go Back

Flex the EP drive assembly to remove the right side of the camshaft from the boss (G), and lift to remove the camshaft.

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Installation notes:

On the left side, align the mark on the idler gear (A) with the mark on the camshaft gear (B), and slide the camshaft into place, meshing the gears on the left side.

Go Back

A B

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Rotate the camshaft up using the camshaft actuator handle (C), and make sure the gears on the right side mesh so the first gear tooth of the camshaft aligns with the first two gear teeth of the EP drive actuator rack (D).

Note:

Make sure the actuator rack on the EP drive is all the way back.

Flex the EP drive on the right to seat the end of the shaft into the boss (E) on the EP drive.

Go Back

Make sure the left and right camshaft brackets are fully seated, and replace the two screws (F).

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Rotate the camshaft using the camshaft actuator handle, and replace the two screws (G).

Go Back

Replace the screw in the EP drive that allowed you to flex the EP drive, and tighten the other screw (see step 6 of the removal).

Replace the top access cover assembly.

Replace the fuser, the cartridges, and close the covers.

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Transfer module removal

See

“Transfer module” on page 7-7

for the part number.

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access cover assembly.

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.

Go Back

B C

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Note:

If you are removing the transfer module to access another part, leave the photoconductor units attached, and you are done. If you need to replace the transport belt, continue with the next step to remove the separate photoconductor units.

Remove the photoconductor units. Lift the right end handle (D) of the photoconductor unit, releasing from the mount.

Lift the unit up and away from the left side of printer, ensuring the left end of the photoconductor is released from the holding pin (E).

Go Back

Installation note:

•

Place the photoconductor units on the new transport belt, and reinstall.

•

Perform the Color Alignment in the Configuration Menu:

Enter Config Menu (turn off the printer, press and hold buttons 3 and 6, turn the printer on, and release the buttons when the clock graphic displays).

Select Color Alignment from the Configuration Menu.

Select Print Alignment Page.

Select Set A.

Consulting the printed page, follow the instructions on the operator panel to choose the best appearing line numbered 0 through 20 for line A.

Continue selecting the best lines for the sets through Set L.

Select Back ( ) to return to the Configuration main menu, and select Exit Config Menu.

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Transport cable removal

“Low-voltage power supply (LVPS) removal” on page 4-119

Remove the transport belt assembly. Leave the photoconductor units in place. See

“Transfer module removal” on page 4-171

Disconnect the transport cable from the system board at JTPS1 connector (A).

Note:

The cable connector on the system board end of the cable is smaller than the connector on the front access door, and it may be easier to get that end through the openings.

Go Back

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Extract the cable through the opening in the frame to the right side of the printer (B).

Remove the cable from the five cable restraints (C).

Remove the cable from the three openings in the cable channel (D) on the right side of the front access door.

Go Back

Remove the six screws (E) from the cable shield.

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Remove the cable through the cable channel (F).

5026

Go Back

Transport motor cable removal

Remove the right cover. See

Disconnect the cable from the transport motor drive (A).

Disconnect the cable from the transport motor (B).

Remove the cable.

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Waste toner assembly removal

Not a FRU.

Press the waste toner release latch (A).

Swing the front of the waste toner assembly away from the printer, and remove.

Go Back

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Waste toner HV contact assembly removal

Disconnect the transfer module cable (A).

Press the two tabs (B) to release the front access cover assembly.

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.

Go Back

B C

Remove the left cover. See

Remove the wireless network card. see

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Remove the six mounting screws (D) holding the HVPS in place.

Go Back

Release the locking tab (E) from the front, lower corner of the HVPS.

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Lay the board to the left.

Disconnect the three top toner level sensor cables (F) from the HVPS.

5026

Go Back

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5026

Remove the two screws (G).

Go Back

G (18B1236)

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10.

Remove the cleaner shutter actuator (H) from the waste toner HV contact assembly.

5026

Go Back

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11.

Remove the four screws (J), the two screws (K), and the screw (L). Tilt the Waste toner HV contact assembly forward and up to remove it.

Go Back

J (18B0832) K (88A0313)

L (27S2838)

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Installation note:

Do the following procedures when re-installing the waste tone HV contact assembly:

Remove the fuser.

Remove all four toner cartridges

Remove the four sets of torsion springs. Remove the screw (A) and the spring cap (B) of the appropriate contact spring.

Go Back

A B

Press the lower half (C,D) of the springs, and remove the springs.

C D

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Install the waste toner HV contact assembly into place. Route the toner level sensor cables (E) through the holes in the waste toner HV contact assembly while positioning the assembly. Make sure the aligner shaft worm gear is aligned as shown.

Ribs aligned Rib

Go Back

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Install the seven screws in the order shown below.

Install 3 rd

(

27S2838

)

5026

Go Back

Install 4 th

(18B0832)

Install 1 st

(18B0832)

Install 2 nd

(88A0313)

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5026

Use two screws (F) to attach the cleaner shutter actuator to the Waste toner HV contact assembly. Make sure the gear aligns as shown.

Ribs aligned Rib

Go Back

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F (27S2838)

5026

Attach the eight springs (G) to the Waste toner HV contact assembly as shown. Make sure the springs are behind the retainers.

Retainer

Go Back

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Install the contact springs. When installing each contact spring, make sure the top half (H) of the spring is under the straight spring (J). This is typical for both types of springs. Also make sure that the bottom half

(K,L) of both springs are compressed and locked by the appropriate locking tabs (M,N).

K J

Go Back

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10.

Connect the three top toner level sensor cables to the HVPS, making sure the cables (O) are attached properly to the retainers (P).

Go Back

11.

Reassemble the rest of the printer.

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Wireless network antenna removal

“Wireless network card removal” on page 4-191

Disconnect the wireless network antenna cable (A) from the wireless network card.

Go Back

With pliers, squeeze the inner tabs (B), and pull the antenna out.

Pull the cable through, and remove the antenna with the cable.

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Wireless network card removal

Remove the rear frame cover. See