Lexmark 5056 User Manual

©

Lexmark™ C920

5056-xxx

Lexmark Repair Catalog

The following information is from Lexmark's Service Mnaual.

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The

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5056-XXX

Repair information

Handling ESD-s e ns it i ve p ar ts

Many electronic products use parts that are known to be sensitive to electrostatic discharge (ESD). To prevent
damage to ESD-sensit ive parts, use the following instructions in addi tion to all the usual precautions, such as
turning off power before removing log ic boards:

• Keep the ESD-sensitive part in its original shi pping container (a special “ESD bag”) until you are ready to

install the part into the machine.

• Make the least-po ssibl e movement s with your body to pr event an in crease of static electr icit y from cl othing

fibers, carpets, and furniture.

• Put the ESD wrist str ap 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-sen siti ve part by it s edge con nect or shr oud ( cover) ; do not touch i ts pi ns. I f you ar e r emoving

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 t he

ESD-sensitive part for any reason, firs t put it into its special bag.

• Machine covers and m etal tables are electrical grounds. They i ncrease 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. Ins tal l machine covers

when you are not working on the machine, and do not put unprotected ESD-sensitive parts on a tab le.

• If possible, keep all ESD-sensitive par ts in a grounded metal cabinet (case).

• Be extra careful in working with ESD-sensitive parts when cold-weather heati ng is used because low

humidity inc reases static electricity.

Service precautio ns

Observe the following precautions whenev er you service the printer :

• Be sure to unplug the print er from the outlet before at tempting to service the pri nter.

• To reassembl e the printer, reverse the order of disassembly unless otherwise speci fi ed.

• Do not operate the print er anytime during disas sembly. If it is absolutely necessary to run the print er wi th

its cover s rem oved, d o not a llow y our clot hing t o be caught i n revol ving par ts such as the gea rs, r olle rs, an d
fan motor.

• Never touch the terminals of electrical parts or high-voltage parts such as the HVPS (high voltage power

supply) board.

• Be sure to handle the fuser carefully, as it remains hot for a while after the printer stops running. Always

unplug connector s by holding the connector housing.

• Be sure to use the fuse list ed in the parts catalog.

• Do not forget to install the ground wire or ground plate to ensure positive conduction. Install the screw with

a toothed washer in the correct position at reassembly.

Repair informatio n 4-1

5056-XXX

RIP board/operator panel replacement

Warning: If the operator panel and the RIP board are being replaced at the sam e time, replace the parts in

this order to avoid dama ge to the machine.

1. Replace the RIP card first.

Note: Do not replace the new operator panel and RIP card in the machine at the same time.

2. After installing the new RIP card, and before inst alling the new operator panel , start the printer.

3. After the printe r has completed startup, tur n off the printer and repl ace the operator panel.

Note: If the operator panel display has failed, the printer s’ startup cycle is complete when the driver motor

and fans shut down, and the machine is quiet.

4. After installing the new operator panel , start the printer, and allow the pri nter to go through a complete

startup cycle and the display to go to Ready.

5. If the problems persist, leave the new operator panel in the machine, place the old RIP card back in the

machine, and star t it up. After the machine startup, shut down the machine, and inst all the new RIP card.

After installing the new RIP card, restart the machine, and let it go through the startup cycle.
After this procedure is completed successfully, there is no need to adjust any settings.
If the above proced ure fails, you must cont act the technical suppo rt center for further instructions.

Handling printed circuit boards

The following precautions must be observed when handling circuit boards with metal oxide semiconductor
integrated circuits.

CAUTION: If you are removing the motor driver board or the low voltage power supply boards,
ensure they are prope rl y discharged before handling.

Transportation/storage

•

During transpo rt ation or when in storage, new cir cuit boards must not be indiscriminately removed from

their protecti ve conductive bags .

• Do not store or place circuit boards in a location exposed to direct sunlight.

• When it becom es absolutely necessary to remove a boar d from its conductive bag o r case, always place it

on its conductive mat in an area as free as possible from static electricity.

• Do not touch pins of the integrated circuits with your bare hands.

Replacement:

•

Before you unplug con nectors from the circuit boards, be sure the power cord has been unplugged from

the power outlet.

• When you remove a board f rom its conductive bag or case, do not touch the pins of the integrated circuits

or the printed patt ern. Place it in position by holding only the edges of the board.

• Before you plug connectors into the board, be sure the power cord has been unplugged from the power

outlet.

Inspection:

Avoid checking the integrated circuits directly with a multimeter; use connectors on the board.

•

• Never create a closed circuit across integrated circuit pins with a metal tool.

• When it is absolutely necessary to touch the integrated circuits and other electrical components on the

board, be sure to ground your body.

4-2 Service Manual

5056-XXX

Check finisher alignment when moving or servicing the finisher

After moving or servicing the finisher, print some test pages to the finisher to ensure the vertical and hori zontal
alignment is correct. If the finish er is not properly aligned, refer to “Aligning the finisher and printer” on

page 3-59 for alignment instructions.

Repair informatio n 4-3

5056-XXX

Adjustments

High-capacity paper feed timing belt adjustment

1. Secure the bracket with the screw, as shown.

2. Attach the spring and washer to the bracket with the screw.

3. Adjust the screw to 6mm ±1mm.

4. Tighten the screw completely.

5. Adjust the timing bel t on the rear in the same manner.

Adjustments and procedures following parts replacement

Note: When troubleshooting, or pr ior to making any adjustment to pr int quality, always be sure:

• The printer is installed on a level, rigid surface.

• The photodevelopers are never exchanged. Do not exchange a black photodeveloper for a color

photodeveloper, as they have different surface phase counts.

• The Alignment Page is used when adjusting print registration.

Whenever you replace any of the following parts, be sure to perform the required adjustments or procedures.
The adjustments are in the Repair information and Diagnostic aids chapters.

Printer controller board/printer control EPROM (U7)

If you replace the pri nter controller board, remove EPROM (U7), and install it on the new board. Also check the
printhead alignment.

Printhead controller board

If you replace the pri nthead controller board, replace all the eeproms from the old printhead controller board .

RIP controller board

If you replace the RIP cont roller board, move the memor y, and option cards from the old card to the new one.

4-4 Service Manual

5056-XXX

Transfer belt

If you replace the transfer belt, check the printer alignme nt (X, Y, and Theta), adj usted in diagnostic mode .

LED printhead controller board or LED printhead

If you replace the LED printhead controller board or LED printhead, check and adjust the following items in
diagnostic mode:

Printer Alignment (X, Y, and Theta)
Print the alignment pages. Make sure that you install ed the EEPROMS supplied with the printhead on the

printhead cont roller board.

Repair informatio n 4-5

5056-XXX

Removals

Cover, top removal

1. Open the top unit, and remove the photodevelopers and toner cartridges. Cover the photodevelopers to

avoid damage from exposure to the light.

2. Remove the two silver screws, and remove the spacer.

3. Remove five black scr ews from the bottom and the four si lver screws from the back si de.

4. Remove the top cover.

Note: When replacing the top cover, avoid pinching or cutting wires that connect the printhead controller

board to the face down unit.

4-6 Service Manual

5056-XXX

Front door / operator panel removal

Warni ng: If the operat or panel and the RIP board are being replaced at the same time, replace the parts
in the order described in steps a through d below to avoid damage to the machine.

a. Replace the RIP card (this m ust be the first part replaced).
b. Restart the print er. Let the machine finish the startup cycle, which takes sever al minutes. The

machine is silent when startup is complete.

c. Install the new operator panel.
d. Restart the printer and let the startup cycle complete.

If the above proced ure fails, contact the technical support center for further inst ructions.

1. Open the front door of the printer.

2. Remove the screws (A) fr om the st iffener bracket.

3. Remove the stif fener bracket.

4. Clip the wire tie that holds the USB and operator panel cables to the door.

Note: Refasten and properly route the cabl es using a wire tie to avoid pinc hing them with the stiffener.

5. Unplug the two cable s fr om the operator panel.

Note: T o continue removing only the operator panel, skip steps 6 and 7

6. Unscrew the four screws (B) that hold the front door moun ti ng brackets to the printer.

7. Remove the front door from the printer.

Repair informatio n 4-7

5056-XXX

8. Remove six screws (C) that hol d the operator panel to the front door.

9. Remove the operator pan el from the door.

Note: If the USB cable or the operator panel cable is being replaced, use the tor oids from the old cables with

the new cables.

Cover, front left removal

1. Open the front cover and remove the cassette.

2. Remove the left front cover by removing the three silver screws.

4-8 Service Manual

5056-XXX

Cover, rear removal

1. Open the top unit.

2. Remove the three silver screws from the rear cover, and then remove the cover.

Cover, solenoid removal

1. Remove the screw from the solenoid cover.

2. Remove the solenoid cover .

Cover, left side removal

1. Remove the upper cassette, front cover, paper exit tray, and duplex unit.

2. Remove the five screws from the left side cover, and remove the cover .

Repair informatio n 4-9

5056-XXX

Cover, right side removal

1. Open the top unit, and remove the front cover and upper cassette.

2. Remove the operator panel cable and the USB cable from the operator panel.

(See “Front door / operator panel removal”.)

3. Remove the seven screws fr om the ri ght side cover together with the turn guide, and remove the cover.

4. When installing the right side cover, insert the turn guide shaft into the bearing.

4-10 Service Manual

5056-XXX

Cover, RIP board removal

Warning: If the operator panel and the RIP board are being replaced at the sam e time, replace the parts in

this order to avoid dama ge to the machine.

1. Replace the RIP card first (this must be the first part replaced).

2. Restart the p rinter. Let the machine finish th e start up c ycle. This ta kes a few mi nutes. The mach ine is si lent

when sta rt up is com p le te .

3. Install the new operator panel.

4. Restart the print er, and let the startup cycle complete.

If the above proced ure fails, you must cont act the technical suppo rt center for further instructions.

1. Loosen the eight scr ews, and remove the RIP cover by sliding upward.

2. Disconnect all harnesses except for the processor fan (J25) from the RIP board connector.

3. Remove the two screws from the parallel port connecto r and the screw from the USB connector.

4. Remove the eight screws fr om the RIP board together with the parallel connector, and remove the RIP

board.

Note: After replacing any bo ard on the pr inte r , ensure al l the con nect ions ar e properl y connect ed be fore cl osing
the covers.

Repair informatio n 4-11

5056-XXX

Tray, paper exit removal

1. Unlatch the hinge at the back side, then unlatch the hinge on the front side.

2. Remove the paper exit tray.

Belt up/down clutch removal

1. Remove the RIP cover, electronic box, printer controller card, and HVPS board.

2. Unplug the belt up/down cl utch cable from CN1 in the CK1 daughte r card board.

3. Remove the C-clip from the bel t up/down clutch, and remov e the cl utch.

4-12 Service Manual

5056-XXX

Cassette guide removal

1. Remove the paper feed fram e.

2. Remove the front cover, cassette, turn guide, right side cover , and paper feed frame.

3. Remove the screws from the cassette guide, and rem ove the guide.

CK1 daughter board removal

1. Remove the front, rig ht, left rear, and rear covers.

2. Remove printer controller board and HVPS board.

3. Disconnect all cables from the daughter board.

4. While pinchin g the nyl on standoffs that attach the card to the printer frame, gently pull t he CK1 daughter

board away from the print er frame.

Note: After replacing any bo ard on the pr inte r , ensure al l the con nect ions ar e properl y connect ed be fore cl osing
the covers.

CK2 daughter board removal

1. Remove the front, rig ht, left rear, and rear covers.

2. Remove pow er su pp ly 1.

3. Unplug all cables from the daughter board.

4. Remove four screws from the daughter board, and remove the board.

Note: After replacing any bo ard on the pr inte r , ensure al l the con nect ions ar e properl y connect ed be fore cl osing

the covers.

Repair in fo rmation 4-13

5056-XXX

Connector, duplex unit removal

1. Open the top unit and remov e the upper cassette, left f ront cover , paper feed cover, left side cover, RIP

cover, RIP board, RIP box, and the electroni c box. Remove the turn guide, open the paper feed cov er, and

remove the duplex uni t. Remove the left side cover and power supply A.

2. Disconnect the connector, and remove the two screws from the mounting plate.

3. Remove the two screws of the drawer connector from the mounting plate drawer bracket.

Paper tray lift motor removal

1. Remove the front, rig ht, left rear, and rear covers.

2. Remove the cassette.

3. Disconnect the cable from the paper tray lift motor.

4. Remove the three black screws from the paper tray lift motor.

5. Remove the paper tray lif t motor.

4-14 Service Manual

5056-XXX

Density sensor removal/Separation fingers removal/Sensor cleaner removal

1. Open the top unit and remov e the bel t unit.

2. Remove the three screws from the sensor bracket.

3. Remove the harness band and remove the two screws from the density sensor from the sensor bracket.

4. Remove the three set scr ews from the sensor cleaner assembly from the sensor br acket.

5. Remove the four separating finger screws fr om the fuser entrance guide .

Drive gear unit sensor assembly removal

1. Open the top unit, and remove the gear cover, RIP cover, RIP board, RIP box, electronic box, printer

controller, and high voltage power supply board.

2. Remove the screw from the drive gear unit sensor assembly.

3. Remove the two screws of the drive gear unit sensor from the drum drive gear sensor assembly.

Repair in fo rmation 4-15

5056-XXX

Electronic box removal

1. Open the top unit, and remove the back cover.

2. Remove the RIP board cover.

3. Remove the RIP board.

4. Remove the screws from the electronic box.

5. Disconnect all cables from the rear of the electronic box, and remove the box.

4-16 Service Manual

5056-XXX

Face up paper exit assembly removal

1. Open the top unit, and remove the upper cassette. Open the duplex cover, and remove the duplex unit.

2. Remove the left front cover, left side cover, and rear cover.

3. Remove the three screws from the face up delivery assembly, and remove the assembly.

Front cover open switch actuator removal

1. Open the front cover.

2. Remove the two screws from the front cover open switch actuator.

Repair in fo rmation 4-17

5056-XXX

Fuser removal

1. Open the top unit.

2. Pushing the front and back lock, hold the handle, and then raise and remove the fus er.

4-18 Service Manual

5056-XXX

Gear cover removal/Multipurpose feeder frame assembly

1. Open the top unit, and remove the upper cassette, front cover, multipurpose feeder, right side cover, and

turn guide.

2. Remove the two screws fro m the gear cover, and remove the cover.

3. Remove the four screws from the multipurpose feed er frame and the ground screw.

4. Disconnect the connector of the multipurpose feeder paper feed sensor.

5. Pull out the multipurpose feeder frame slightly.

6. Remove the screw from the OHP dete ction sensor (upper) .

7. Turn the bearing stopper of the multipurpose feeder roll forward

1/4 turn, and remove upward.

8. Remove the multipurpose feeder frame assembly.

Repair in fo rmation 4-19

5056-XXX

High voltage power supply boar d (HVPS) removal

Note: When removing the high voltage power supply , be careful to avoid dama ging the secondary daughter
card (Q906). If the daughter card gets damaged, a 925 service error will result.

1. Open the top unit, and remove the RIP cover, RIP board, RIP box, electronic box, and printer controller

board.

2. Remove the five scre ws from the printer controller board bracket.

3. Remove the connectors, and then remove the 12 screws.

4. Remove the HVPS board.

Note: After replacing any bo ard on the pr inte r , ensure al l the con nect ions ar e properl y connect ed be fore closi ng

the covers.

LED printhead removal

1. Open the top unit, remove the top cover , toner cartridges, and photodeveloper drum units.

Note: Remove the transfer belt, or spread a cloth or paper over the transfer belt to p rotect it from dam age.

2. Remove the short black screw from the printhead holder, and remove the holder.

3. Remove the front and rea r printhead springs.

4. Remove the two screws (front and rear) from the right slide rail, and remove the rail.

Note: When replacing the rail, be sure to use the short black screw. A longer screw can interfere with the LED

head causing the image to be out of focus.

4-20 Service Manual

5056-XXX

5. Disconnect t he affected LED p ri nthead connector s from the printhea d controller board. Remove the screw

from the ground wire located on the LED printhead.

6. Remove the LED printhead and the cables from the printer.

When replacing the LED prin thead, replace the corresponding EEPROM, shipped with the printhead, on
the printhead contr oller board.
Note: The LED printhead light intensi ty values do not have to be entered for the printer.

Eraser removal

1. Remove the appropriate printheads (see “LED printhead removal” on page 4-20). Spread a cloth over

the transfer belt to pr otect it from damage.

2. Remove the two screws from HSP holder, and remove the holder.

3. Remove the top cover.

4. Disconnect the eraser cable from the printhead controller boar d.

C–CN06
M–CN05
Y–CN07
K–CN08

5. Carefully thread the eraser cable through the upper unit and remove the eraser.

Repair in fo rmation 4-21

5056-XXX

Lock handle assembly removal

1. Open the top unit.

2. Turn the pl astic latch on the front and re ar si des 90°.

3. Remove the spring.

4. Remove the lock handle assembly.

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Main drive unit removal

1. Open the top unit , and remov e th e gear cover, upper cassette, left front cove r, paper feed cover, RIP cover,

RIP board, RIP box, electronic box, and rear cover.

2. Open the turn guide and pape r feed cover , and remove the duplex unit.

3. Remove the left side cover, power unit 1, and power unit 2.

4. Remove the printer controller board.

5. Remove the bracket, HVPS board, and sub frame R.

6. Remove the fuser unit, f ace up paper delivery unit, bel t up/down clutch, and DC drive motor.

7. Remove the multipurpose feeder roll, registration roll, and paper carrying frame.

8. Remove the eight screws from the power supply 2 bracket.

9. Remove the two screws from the belt power supply 2.

10. Remove the two screws from the fan bracket.

11. Remove the three screws from the fuser connector plate.

12. Remove the two screws of the fuser connector cable assembly from the fus er connector plate.

Note: Note the direction, when installing.

13. After removing the two screws on the bracket that attaches the rear side and paper exit side of the

machine, remove the nine screws from the brack et.

Repair in fo rmation 4-23