OKI PAGE 20 Service manual

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OKIPAGE20 / OKIPAGE20n

LED Page Printer

Maintenance Manual

ODA/ OEL/ INT

All specifications are subject to change without notice.

PostScript, Adobe and the PostScript logo are trademarks of Adobe Systems Incorporated, registered in the U.S.A. *Times, Helvetica and Palatino are trademarks of Linotype AG and/or its subsidiaries. ITC Avant Garde Gothic, ITC Zapf Chancery, ITC Zapf Dingbats and ITC Bookman are registered trademarks of International Typeface Corporation. HP and LaserJet are registered trademarks of Hewlett-Packard Company. Diablo 630 is a registered trademark of Xerox corporation. AppleTalk is a registered trademark of Apple Computer, Inc. LocalTalk is a trademark of Apple Computer, Inc.

PREFACE

This maintenance manual describes the field maintenance methods for OKIPAGE20 / OKIPAGE20n. This manual is written for use by maintenance personnel. Note, however, that the user should refer to

the USER’S MANUAL for methods of handling and operating the equipment.

1. CONFIGURATION....................................................................................... 1 - 1

1.1 System Configuration................................................................................................. 1 - 1

1.2 Printer Configuration .................................................................................................. 1 - 2

1.3 Optional Configuration ............................................................................................... 1 - 3

1.4 Specification............................................................................................................... 1 - 5

1.5 Safety Standards ....................................................................................................... 1 - 7

1.5.1 Certification label .......................................................................................... 1 - 7

1.5.2 Warning label................................................................................................ 1 - 7

2. OPERATION DESCRIPTION ...................................................................... 2 - 1

2.1 Main Control Board (BOARD-AAA) ........................................................................... 2 - 3

2.2 Power Supply Unit ..................................................................................................... 2 - 7

2.3 Electro-photographic Process.................................................................................... 2 - 9

2.3.1 Electro-photographic process mechanism ................................................... 2 - 9

2.3.2 Electro-photographic process ....................................................................... 2 - 11

2.3.3 Process operation descriptions .................................................................... 2 - 15

2.3.4 Revision of LED Head Illumination ............................................................... 2 - 25

2.4 Paper Jam Detection ................................................................................................. 2 - 33

2.5 Cover Open................................................................................................................ 2 - 34

2.6 Toner Low Detection.................................................................................................. 2 - 35

2.7 Stacker-full Detection................................................................................................. 2 - 37

2.8 Page Size Detection .................................................................................................. 2 - 37

2.9 PostScript ROM module (BOARD-MSM or BOARD-FSL)......................................... 2 - 37

3. PARTS REPLACEMENT............................................................................. 3 - 1

3.1 Precautions for Parts Replacement ........................................................................... 3 - 1

3.2 Parts Layout...............................................................................................................3 - 3

3.3 How to Change Parts................................................................................................. 3 - 6

3.3.1 Face -up Stacker Assy ................................................................................. 3 - 7

3.3.2 Contact Assy ................................................................................................ 3 - 8

3.3.3 DC Fan Motor ............................................................................................... 3 - 9

3.3.4 OP Panel Assy ............................................................................................. 3 - 10

3.3.5 Board-AAA....................................................................................................3 - 11

3.3.6 Stacker Assy, Damper Arm, Cover Rear..................................................... 3 - 12

3.3.7 Sensor Stacker Full ...................................................................................... 3 - 13

3.3.8 Cable cover (guide film)................................................................................ 3 - 14

3.3.9 Damper......................................................................................................... 3 - 15

3.3.10 Feeder Unit-Front ......................................................................................... 3 - 16

3.3.11 Roller Assy-Regist ........................................................................................ 3 - 17

3.3.12 Motor -Main .................................................................................................. 3 - 18

3.3.13 Guide Assy-Eject .......................................................................................... 3 - 20

3.3.14 Heat Assy ..................................................................................................... 3 - 21

3.3.15 Roller feed (C) .............................................................................................. 3 - 22

3.3.16 Roller Assy-BK ............................................................................................. 3 - 23

3.3.17 Roller Assy-Feed .......................................................................................... 3 - 24

3.3.18 LED Head ..................................................................................................... 3 - 25

3.3.19 Paper cassette, ROLLER Ass-Feed, ROLLER-Assy-Hoppibg..................... 3 - 26

3.3.20 Frame Assy-Separation................................................................................ 3 - 27

3.3.21 Transfer Roller/TR Gear/TR Bearing............................................................ 3 - 28

3.3.22 EP lock shaft................................................................................................. 3 - 29

3.3.23 LEVER Assy- Out Sensor............................................................................. 3 - 30

3.3.24 Toner sensor lever........................................................................................ 3 - 31

3.3.25 Paper sensor lever ....................................................................................... 3 - 32

3.3.26 Inlet sensor lever ..........................................................................................3 - 33

3.3.27 Power supply unit ......................................................................................... 3 - 34

3.3.28 Lever-Paper end & Lever-Paper near end ................................................... 3 - 35

3.3.29 Guide Assy-Cassette (L) .............................................................................. 3 - 37

3.3.30 Guide Assy-Cassette (R)..............................................................................3 - 38

4. ADJUSTMENT............................................................................................. 4 - 1

4.1 Maintenance Modes And Functions........................................................................... 4 - 1

4.1.1 User maintenance mode .............................................................................. 4 - 3

4.1.2 System maintenance mode .......................................................................... 4 - 7

4.1.3 Engine maintenance mode...........................................................................4 - 10

4.1.4 EEPROM initialization .................................................................................. 4 - 14

4.2 Adjustment When Replacing A Part........................................................................... 4 - 15

4.2.1 Resetting the fuser counter .......................................................................... 4 - 16

4.2.2 Destination setting ........................................................................................ 4 - 17

4.2.3 Setting of LED head drive time.....................................................................4 - 18

5. PERIODIC MAINTENANCE ........................................................................ 5 - 1

5.1 Periodic Replacing Part ............................................................................................. 5 - 1

5.2 Cleaning..................................................................................................................... 5 - 1

5.2.1 Cleaning of LED lens array........................................................................... 5 - 1

5.2.2 Cleaning the Plastic Film .............................................................................. 5 - 2

6. TROUBLESHOOTING PROCEDURES ...................................................... 6 - 1

6.1 Troubleshooting Tips ................................................................................................. 6 - 1

6.2 Points to Check before Correcting Image Problems.................................................. 6 - 1

6.3 Tips for Correcting Image Problems .......................................................................... 6 1

6.4 Preparation for Troubleshooting ................................................................................ 6 - 2

6.5 Troubleshooting Flow................................................................................................. 6 - 2

6.5.1 LCD status message/trouble list...................................................................6 - 2

6.5.2 LCD message troubleshooting .....................................................................6 - 14

6.5.3 Image troubleshooting .................................................................................. 6 - 34

7. WIRING DIAGRAM...................................................................................... 7 - 1

7.1 Interconnect Signal Diagram...................................................................................... 7 - 1

7.2 PCB Layout................................................................................................................7 - 2

7.3 Resistance Check...................................................................................................... 7 - 5

7.4 Program/Font ROM Location ..................................................................................... 7 - 7

8. PARTS LIST ................................................................................................ 8 - 1

APPENDIX A CENTRONICS PARALLEL INTERFACE ................................ A - 1

APPENDIX B RS-232C SERIAL INTERFACE ............................................... B - 1

APPENDIX C DUPLEX UNIT.......................................................................... C - 1

APPENDIX D Second/ Third Paper Feeder.................................................. D - 1

APPENDIX E Multi Feeder ............................................................................ E - 1

1. CONFIGURATION

1.1 System Configuration

OKIPAGE20 / OKIPAGE20n consists of control and engine blocks as the standard configura-

tion (See Figure 1-1.)

In addition, the following options are also available.

PC etc.

Centronics

Parallel interface

(Bidirection)

RS-232C

Serial I/F

Printer

Operator

panel

Main control

Power supply

unit

DC Fan

Face down

stacker

Printer

Mechanism

I/D unit

LED head Motor-Main Hopping motor

AC IN

120V 230V

Face up

stacker

Toner Cartridge

Front Feeder

LAN etc.

OKI HSP

interface board

(Option)

Extension D-RAM

SIMM

(Option)

4MB/ 8MB

Flash ROM SIMM

(Option)

: Paper feeding : Singal flow

PostScript

SIMM

(Option)

Figure 1-1

1 - 1

Paper tray

Paper size

detection switch

High Capacity Second Paper

Feeder

(Option)

High Capacity

Third Paper

Feeder

(Option)

*: Consumables

: produced by third vender

Multi Feeder

(Option)

Duplex Unit

(Option)

1.2 Printer Configuration

The printer unit consists of the following hardware components:

• Electro-photographic processor

• Paper feeder

• Controller

• Operator panel

• Power supply unit Figure 1-2 shows the printer unit configuration.

Stacker Assy

Frame-OP panel Assy

Plate-Shield

Cover-Side(I/F)

Face-up stacker Assy

Cover-Rear

Cover-Side(L) Assy

Contact Assy

Cover-Frame

Heat Assy

Cover-Side(R)

Manual Feed Assy

Base Unit

Figure 1-2

I/D Unit

1 - 2

1.3 Optional Configuration

The options below are available for use with OKIPAGE20 / OKIPAGE20n. They are sold

separately from the printer unit.

(1) Multi Feeder

(2) Second/ Third Paper Feeder

(3) DUPLEX Unit

1 - 3

(3) D-RAM SIMM module (72 pin SIMM, 4 MB/8 MB/16 MB/32 MB)

(4) Flash ROM module (72 pin SIMM, 4MB/8MB)

See 7.2 (1) for where to install.

(5) PostScript ROM module (72pin SIMM)

1 - 4

See 7.2 (1) for where to install.

1.4 Specification

(1) Type Desk top (2) External dimensions Height 13.0” (331 mm)

(excludes protruding Width 14.4” (366 mm)

Portion) Depth 18.2” (462 mm) (3) Weight 19.0 kg (42 lbs) If Installed Duplex 21.3 kg (47 lbs) (4) Development method Dry electrophotography

Exposure method LED stationary head (5) Paper used <Type>

• Standard paper – Xerox 4200 (20 lbs)

• Application paper (manual face-up feed) – Label – Envelope – OHP paper (Transparency)

<Size>

• Standard sizes – Letter – Legal – Executive – Envelope (without Duplex printing) –A4 – A5 (without Duplex printing) – B5 (without Duplex printing) – A6 (without Duplex printing)

• Applicable sizes – Width: 3.4” to 8.5” (86 to 216 mm) – Length: 5.5” to 14” (140 to 355.6 mm)

– Automatic feed: 16 to 28 lbs (60 to 105 g/m2) – Manual feed: Label, OHP paper (transparency)

Envelope, 16~36 lb

(6) Printing speed First print: 8 sec.

Continuous print: 20 sheets/min.

[at duplex print :10 sheets/min]

Warm-up time: 90 sec. [at room temperature 77˚F

(25˚C) and rated voltage (120 VAC)] (7) Paper feed method Automatic feed or manual feed (8) Paper delivery method Face down/face up (9) Resolution 600 x 600 dots/inch (default)

600 x 1200 dots/inch

(10)Power input 120 VAC + 5.5%, –15% (ODA)

230 VAC + 10%

1 - 5

(11) Power consumption Peak: Approx. 820W

Typical Operation: Approx. 350W Idle: Approx. 95W Power save mode: Approx. 25W

(12) Temperature and humidity

In operation Power off mode During Storage Unit

Temperature 50 - 90 32 - 110 14 - 110 °F

(10 - 32) (0 - 43) (–10 - 43) (°C) Humidity Maximum wet

bulb temperature Minimum difference

of wet and dry bulb temperatures

20 - 80 10 - 90 10 - 90 %RH

77 80.4 °F

(25) (26.8) (°C)

35.6 35.6 °F (2) (2) (°C)

Notes:

1. Storage conditions specified above apply to printers in packed condition.

2. Temperature and humidity must be in the range where no condensation occurs.

Temperature

(°C)

Operation range

20 80

Humidity (%)

(13) Noise During operation: 50 dBA or less (without second tray)

55 dBA or less (with second tray) At standby: 45 dBA or less Power save mode: 43 dBA or less

(14) Consumables Toner cartridge kit 5,000 pages(5% duty)*

Image drum cartridge 30,000 pages(at continuous Simplex printing)*

19,000 pages(3 page/job)(Simplex printing)*

* Simplex printing without Power Save.

1 - 6

1.5 Safety Standards

1.5.1 Certification label The safety certification label is affixed to the printer in the position below.

ex. ODA 120V

1.5.2 Warning label The warning label is affixed to the portion which may cause an injury to human body.

Follow the instructions on warning labels during maintenance.

1 - 7

2. OPERATION DESCRIPTION

OKIPAGE20 / OKIPAGE20n consists of a main control board, a power supply unit (120V/230V), a power supply unit (high voltage), an operator panel and an electro-photographic process mechanism.

The control board receives data through a host I/F, decodes and edits the data, and stores the edited data in a memory. After completing edition of one page of data, it references the font memory and generates bit data on the same memory. At the same time, it transfers the bit image data to an LED head in units of one dot line.

The electro-photographic process mechanism prints data on paper. The operator panel is used for operations and status display. Fig. 2-1 shows an OKIPAGE20 / OKIPAGE20n block diagram.

2 - 1

FLASH ROM

Module

PS ROM

Module

MAIN BOARD (BOARD-AAA)

DUPLEX unit

MULTI feeder

Centronics

I/F

RS232C

I/F

LAN etc.

(Option)

ROM

Extension

DRAM

Module

DRAM

7407

75188

OKI

HSP I/F

Board

(Option)

3V 5V +8V -8V 38V

CPU

LSI

EEPROM

TRANSISTOR

DRIVER

2nd tray

Paper end sensor

Paper near end sensor

BOARD PXC

Clutch for

Regist Roller

Clutch for

Hopping Roller

Hopping Motor

Main Motor

Operator panel

LED HEAD

3rd tray

Tray size sensor board

POWER SUPPLY UNIT (AC120V/230V)

Outlet sensor

FILTER CIRCUIT

AC120V/230V

LOW VOLTAGE

GENERATION

CIRCUIT

Inlet sensor1 paper sensor

Inlet sensor2 Toner sensor

LSI

COVER

OPEN

DRIVER

POWER SUPPLY UNIT (high voltage)

HIGH

VOLTAGE

CIRCUIT

Sub-CH

Figure 2-1 OKIPAGE20 / OKIPAGE20n block diagram

THERMISTOR

SUB CHARGE ROLLER

CHARGE ROLLER

TRANFER ROLLER

DEVELOPPING ROLLER

TONER SUPPLY ROLLER

CLEANING ROLLER

FAN

HEATOR

2 - 2

2.1 Main Control Board (BOARD-AAA)

The control board consists of an one chip CPU,a LSI, program/font ROM's, DRAM's, an EEPROM, a host interface circuit, and a mechanism driving circuit.

(1) One-chip CPU

The one-chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 40-MHz clock) that incorporates an RISC CPU and its peripheral devices, and has the following functions.

Built-in device Function

Chip select controller Control of peripheral LSI, ROM, DRAM and I/O device Bus controller DRAM controller

DMA controller Transfer of data from Host I/F to RAM Serial interface controller Control of RS232C serial interface Parallel interface controller Control of Centronics parallel interface Timer Generation of various control timing

Monitoring of paper running and paper size

Serial I/O port Control of serial interface between controller and operator panel, EEPROM

Control of a serial interface between controller and power supply board

I/O port Inputting of various sensor signals

Outputting of various control signals Motor driver controller Control of Main Motor Image processing circuit Executes the image data process for printing.

(2) Program/font ROM's

The program/font ROM's store the HP LJ5 emulation program and various types of font. MASK ROM is used as the program/font ROM's.

2 - 3

(3) DRAM's

4-Megabyte DRAM (16 Mbit DRAM x 2) is mounted as resident memory to be used for storing the program and providing various buffers. This DRAM is expandable up to 68 Mbytes by adding expansion memory (SIMMs). This DRAM provides the areas shown in the following table.

Memory area Use Memory capacity setting

MENU Expansion RAM

System area Fixed Fixed Raster buffer Enable Expandable Receive buffer Enable Expandable

Page buffer – Expandable

DLL/macro buffer – Expandable Font cache buffer Enable Expandable

Working area used for the program Stores converted bit image data Stores temporarily the data received

from the host interface Adds print information to the analyzed

receive data and stores the resulted data.

Stores soft fonts and macro data. Stores bit map fonts generated by the

font rasterizer based on scalable font information

(4) EEPROM

The EEPROM has a 1-kbit capacity and stores the following data.

• Menu data

• Various counter data (page counter, drum counter, fuser counter, etc.)

• Adjustment parameters (LED head drive time, print start position, etc.)

(5) LSI (LZ9FF22)

Built in device Function Serial I/O port Control of serial interface between controller and 2nd tray, 3rd tray, Multi purpose feeder

Control of serial interface between controller and Duplex unit Motor driver controller Control of Hopping motor I/O port Inputting of various sensor signals

Outputting of various control signals

(6) Host interface

This printer has the following interfaces to the host.

• Centronics bidirectional parallel interface

• RS232C interface

• OKI HSP interface (Option) The single effective interface or the automatic interface select mode can be selected using

the menu. If the busy state of the printer continues for a long time period, the buffer nearfull control releases the busy status at constant intervals even if the host side is busy so not to cause the interface time-out at the host side.

2 - 4

(a) Centronics bidirectional parallel interface

This is an interface conforming to IEEE-1284 and provides either of unidirectional and bidirectional communications according to each of the following communication modes.

• Compatibility mode Unidirectional communications from the host to the printer.

• Nibble mode This mode transmits 4-bit wide data from the printer to the host. In this mode, each 1-byte data is transferred in the form of two nibbles using ERROR, BUSY, FAULT, and SELECT signal leads. This mode can provide the bidirectional operation in combination with the compatibility mode.

• ECP mode This mode provides the asynchronous bidirectional interface and transmits and receives 1-byte data using eight data signal leads under the semi-duplex control by the host.

When the power is turned on, the compatibility mode is automatically selected. The change to another mode from the compatibility mode is made through negotiation. (When the BI DIRECTION is set to ENABLE in the menu, this change can be performed.) (For the electrical/physical characteristics of this interface, see APPENDIX B)

(b) RS232C serial interface

The following protocol is supported for the serial interface conforming to EIA RS232C.

• READY/BUSY (DTR HI or DTR LO)

• X-ON/X-OFF

• RBST X-ON

(For the electrical/ physical characteristics of the interface, see APPENDIX B)

This interface (slot) is an OKI unique universal interface that provides the platform to connect various of boards (including those supplied by third venders) such as the LAN connection expansion board and SCSI expansion board. Any expansion boards compatible with this interface can be mounted on the Control board in the piggyback board from without modifying the program at the printer side. The

conceptual diagram of the OKI HSP interface is shown in Fig. 2-2. (For the electrical/physical characteristics of the OKI HSP interface, see the OKI HSP interface technical manual.)

Printer

Network, etc.

Control board

LAN

expansion board

OKI HSP

interface

Fig. 2-2

2 - 5

(7) RAM module

• Pin layout

1363772

• Basic specificaton

- Type: 72 pins Standerd SIMM (32 bits buss width)

- Access time: 60ns, 70ns, 80ns, 100ns

- Capacity: 4, 8, 16 or 32MB

- Parity: None

(8) Flash ROM module

• Pin layout

Board-FSL or Board-FSL-2

(4MB)

[Note : EDO SIMMtype cannot be used.]

(8MB)

1363772

• Basic specificaton

- Type: 72 pins SIIM (32 bits buss width)

- Access time: 90ns

- Capacity: 4 or 8MB

(9) PS ROM module

PS ROM module is BOARD-MSM-2 or BOARD-FSL-2 BOARD MSM-2 consists of MASK ROM

BOARD FSL-2 consists of Flash ROM (8MB).

• Pin layout

BOARD-MSM-2

BOARD-FSL-2

1363772

• Basic specificaton

- Type:72 pins SIIM (32 bits buss width)

- Access time: 100ns (Board-MSM-2), 90n (Board-FSL-2)

- Capacity: 4MB (Board-MSM-2), 8MB (Board-FSL-2)

• Emulation : Pstscript Level 2

2 - 6

2.2 Power Supply Unit

The power supply unit consists of an AC filter circuit, a low voltage power supply circuit, a high voltage power supply circuit, heater drive circuit, and photosensors.

(1) Low voltage power supply circuit

This circuit generates the following voltages.

Output voltage Use

+5 V Logic circuit supply voltage +30 V Motor and fan drive voltage and source voltage for high-voltage supply +8 V Reset circuit, RS232C Line voltage –8 V RS232C Line voltage +3.8V LED HEAD supply voltage

(2) High voltage power supply circuit

This circuit generates the following voltages necessary for electro-photographic processing from +30 V according to the control sequence from the control board. When cover open state is detected, +30 V supply is automatically interrupted to stop the supply of all the high-voltage outputs.

Output Voltage Use Remarks

Sub-CH -15 µA Voltage applied to Sub charging roller CH -1.30 KV Voltage applied to charging roller DB -220 V/+300 V Voltage applied to developing roller SB -450 V Voltage applied to toner supply roller TR +4 KV/-1.3 kV Voltage applied to transfer roller Variable + Only CB +450 V/-1350V Voltage applied to clearimng roller

(3) Photosensor

The photosensor mounted on this power supply unit supervises the paper running state during printing.

2 - 7

Figure 2-3 shows the sensor layout diagram.

Paper running direction

Roller-exit

Roller-feeder (c)

Outlet sensor

Roller-Heat

Roller-transfer

Sensor

Inlet sensor 1

Inlet sensor 2

Toner sensor

Inlet sensor 1

Inlet

sensor 2

Paper sensor

Roller-regist

Feed roller

Figure 2-3

Function

Detects the leading part of the paper and gives the supervision timing for switching from hopping operation to feeding operation.

Supervises the paper running state and the paper size according to the paper reach time and running time.

Detects the form width.

ON: Paper exists. OFF: No paper exists.

ON: A4 or larger OFF: Smaller than A4

Sensing state

Paper sensor

Outlet sensor

Toner low sensor

Detects the leading part of the paper.

Supervises the paper running state.

Supervises the paper feed and size according to the time of arrival to the sensor and the time of passage of paper.

Detects the lack of toner.

ON: Paper exists. OFF: No paper exists.

ON long: Toner low exists OFF short: No Toner low exists

2 - 8

2.3 Electro-photographic Process

2.3.1 Electro-photographic process mechanism This mechanism prints image data from the control board on the paper by electro-photographic

process. The Figure 2-4 shows the layout of the electro-photographic process mechanism.

Front Hopping Roller

Front Feeder

Roller Assy-Feed

Image Drum Unit

Hopping Motor

1st Hopping Roller

Sub Roller

LED HEAD

Motor-Main

Heat Assy

Face Up stacker

Figure 2-4

2 - 9

(1) Image drum unit

The image drum unit consists of a sensitive drum, a charger, and a developer. The unit forms a toner image on the sensitive drum, using a electrostatic latent image formed by the LED head.

(2) Hopping motor

This motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from the control board. It drives the hopping roller of the first tray and the front feed roller via two one-way clutches according to the direction of rotation.

(3) Motor-Main

This motor is a pulse motor of 72 steps/rotation that is two-phase excited by the signal from the control board and is the main motor of this mechanism.

(4) Clutch (for Regist)

Swithes the transfer of power to Roller Regist if necessary depending on the power from Motor-Main and instructions from the control PCB.

(5) Clutch (for Feed Roller)

Swithes the transfer of power to Feed Roller if necessary depending on the power from Motor-Main and instructions from the control PCB.

(6) LED head

Image data for each dot line from the control board is received by the shift register and latch register. The 4992 LEDs are driven to radiate the image data to the image drum.

(7) Fuser

The fuser consists of a heater, a heat roller, a thermistor and a thermostat. An AC voltage from the power supply board is applied to the heater under the control of the HEATON signal from the control board. This AC voltage heats the heater. The control board supervises the heat roller temperature via the thermistor, and regulates the heater roller at a predetermined temperature (185 °C : Normal paper, MEDIA TYPE = MEDIUM) by connecting or disconnecting the AC voltage supply to the heater. If the heater roller temperature rises abnormally, the thermostat of the heater voltage supply circuit is activated to cut the AC voltage supply forcibly.

2 - 10

2.3.2 Electro-photographic process The electro-photographic processing is outlined below. Figure 2-5 shows the electro-photo-

graphic printing process. 1 Charging

The surface of the image drum is uniformly charged with negative charges by applying a negative voltage to the charge roller.

2 Exposure

Light emitted from the LED head irradiates the negatively charged surface of the image drum. The surface potential of the irradiated part of the image drum surface is lowered, so that an electrostatic latent image associated with the print image is formed.

3 Developing and toner recovery

When the negatively charged toner is brought into contact with the image drum, it is attracted to the electrostatic latent image by static electricity, making the image visible. At the same time, the residual toner on the image drum is attracted to the developing roller by static electricity.

4 Transfer

When paper is placed over the image drum surface and a positive charge, opposite in polarity to the toner, is applied to the reverse side of the paper from the transfer roller, the toner is attracted by the positive charge and is transferred to the paper. As a result, the toner image formed on the image drum is transferred to the paper.

5 Temporary cleaning

Residual toner that remains on the image drum without being transferred is made uniform by the cleaning roller and is temporarily attracted to the cleaning roller by static electricity.

6 Fusing

The toner image transferred to the paper is fused under heat and pressure. Figure 2-6 shows an electro-photographc process timing chart.

2 - 11

Toner

cartridge

Toner

supply roller

Front

feeder

Path of paper

feeding

Direction of

rotation of the

image drum

Image data

LED head

Power

supply

(Bias voltage)

Exposure

Doctor

Developing

Charging

blade

Inlet sensor

roller

Paper sensor

Developing

Cleaning

Paper

supply

Paper

registration

Transfer

roller

Hopping

roller

Registration

Image

production

roller

Transfer

Power

supply

developing Paper feed Paper hopping

eject

Paper

roller

eject

Paper

Power

supply

(Face down)

roller

Charger

Power

supply

eject

roller

Paper

Figure 2-5

2 - 12

Cleaning

path

Paper

roller

selector

eject

Paper

Fusing

Outlet sensor

(Face up)

Fusing pressure

Heater roller

Paper eject Fusing Cleaning Transfer

DMON-N (DRUM MOTOR)

OFF ON

2 - 13

Figure 2-6

HMON-N (HOPPING MOTOR)

PWM1-P (CLUCH for hopping)

PWM2-P (CLUCH for REGISTRATION)

PSIN1-N (INLETSENSOR1)

WRSENSE-N (PAPER SENSOR)

PSOUT-N (OUTLET SENSOR)

STB-N (LED HEAD)

OFF ON

ON OFF

OFF ON

PAPER TRAYPAPER PRINTER

SIMPLEX PRINTING TIMING CHART

STACKER

DMON-N (DRUM MOTOR)

OFF ON

2 - 14

HMON-N (HOPPING MOTOR)

PWM1-P CLUCH for hopping)

PWM2-P (CLUCH for REGISTRATION)

PSIN1-N (INLETSENSOR1)

WRSENSE-N (PAPER SENSOR)

PSOUT-N (OUTLET SENSOR)

Figure 2-7

STB-N (LED HEAD)

DUPMON-N (MAIN MOTOR in DUPLEX UNIT)

CLON-P (CLUCH in DUPLEX UNIT)

SLON-P (SOLENOID in DUPLEX UNIT)

DUPINSNS-N (INLET SENSOR in DUPLEX UNIT)

DUPRSNS-N (REAR SENSOR inDUPLEX UNIT)

DUPFSNS-N (FRONT SENSOR in DUPLEX UNIT)

PAPER PRINTER PRINTER STACKERDUPLEX UNIT

OFF ON

ON OFF

OFF ON

ON OFF

OFF ON

PAPER

TRAY

PRINTER/

DUPLEX UNIT

DUPLEX UNIT/

PRINTER

DUPLEX PRINTING TIMING CHART

2.4.3 Process operation descriptions (1) Hopping

Hoppings from the first tray and the front feeder are effected by a single hopping motor in the mechanism shown below.

Hopping Motor

Front Feeder

1st Tray

Turning the Hopping motor in direction a (CW) drives the 1st Hopping Roller. Turning the Hopping motor in direction b (CCW) drives the Front Hopping Roller. Gear C and Hopping roller bult in one-way bearing, so that turning each of these gears in reverse direction will not be transmitted to the corresponding roller.

(One-way Clutch build-in )

Front Hopping Roller

(One-way clutch build-in)

Gear C

(CW)

Hopping Motor

(CCW)

Inlet Sensor

Roller-Regist

Planet Gear

1st Hopping Roller

(One-way clutch build-in)

2 - 15

Gear A

Gear B

Sub Roller

Paper

(a) Hopping from the 1st Tray

1 Hopping

Rotating the Hopping Motor in direction a (CW) drives the 1st Hopping Roller and the Sub Roller then pick up a sheet of paper in the 1st tray. The Main Motor is always driven in direction c (CCW) on printing. After the paper fed approx. 30mm from the tray, the Clutch (Feed) drives the Align Roller to advance the paper until the Inlet Sensor turns on.

2 Aligning

After turning on the Inlet Sensor, the paper fed by a predetermined length and choked up to the wedge space formed by the Regist Roller and the Pressure Roller so that to align the skew of paper.

3 During the paper fed from the 1st tray, the build in clutch of Gear C is idled and not

to drive the Front Hopping Roller.

4 Feeding

After aligned the paper, the Hopping Motor turned off and stop hopping. Also the Clutch (Feed) turned off and the Align Roller idled freely. Then Clutch (Regist) turned on and the Regist Roller start to feed the paper. After the paper fed, the 1st Hopping Roller is freely idled by releasing build in one way clutch, also the Sub Roller is freely idled by escaping the Planet Gear.

5 Start printing. after the paper turns off the Write Sensor.

Align Roller

Clutch (Feed)

Gear D

Pressure Roller

Inlet Sensor

Regist Roller

Gear E

Clutch (Regist)

Write Sensor

Main Motor

2 - 16

(b) Hopping from the Front Feeder

1 Hopping

The Front Feeder Plate is normally locked at the lower position by the Release Lever and turn the Micro SW on. Top of the FF Cam which attached on end of the Front Hopping Shaft is normally located Upper position (0 to 30 degree : home position). Rotating the Hopping Motor in direction b (CCW) drives the Front Hopping Shaft and then attached the FF Cam and the Front Hopping Roller are driven. During the FF Cam rotated approx. 60 degree, the Release Lever was pushed and the Front Feeder Plate lifts up, then the Front Hopping Roller picks up a sheet of paper. At the FF Cam rotated approx. 180 degree, the Front Feeder Plate is pushed down and locked by the Release Lever again. At the FF Cam rotated approx. 275 degree the paper fed until the Inlet Sensor turns off.

2 Aligning

After turning on the Inlet Sensor, the paper fed by a predetermined length and choked up to the wedge space formed by the Regist Roller and the Pressure Roller so that to align the skew of paper.

3 During the paper fed from the Front Feeder Plate, the one way clutch of 1st Hopping

Roller is idled and not to drive the 1st Hopping Roller and the Sub Roller.

4 Feeding

After aligned the paper, the Hopping Motor turned off and stop hopping. Then Clutch (Regist) turned on and the Regist Roller start to feed the paper. After the paper fed, the Front Hopping Roller drives the Front Hopping Shaft and attached the FF Cam with small idle torque of build in one way clutch and when comes into the Release Lever, the one way clutch is slipped and the FF Cam is stopped at the upper position (home position). The Front Hopping Roller continuously idled up to the paper away.

5 Start printing. after the paper turns off the Write Sensor.

2 - 17

Hopping Roller

(Front Feeder)

Gear C

(one way clutch build in)

Hopping Motor

b (CCW)

Pressure Roller

Front Feeder Plate

Paper

Gear A

Hopping Roller

Inlet Sensor

1st Hopping Gear

(One way Gear build in)

Regist Roller

Paper

Sub Roller

0~30°

Release Lever

Front Feeder Plate

(home position)

Front Hopping Shaft

FF Cam

Micro SW

60°

180°

2 - 18

Align Roller

Clutch (Feed)

Gear D

Pressure Roller

Inlet Sensor

Regist Roller

Gear E

Clutch (Regist)

Write Sensor

Main Motor

(2) Feeding

After the end of hopping, the pulse motor dedicated for driving the registration roller rotates to drive the registration roller. The driven registration roller advances the paper until it comes out of the registration roller.

When leading edge of the paper causes the paper sensor to turn on, the printing is started synchronously.

Although Gear D is always rotating due to an all-time rotation of the main motor in direction c, the regist roller would not rotate because the clutch (regist) is turned off. After the completion of hopping, turn on the clutch (regist) to drive the regist roller. The regist roller would drive a paper until the paper has passed.

2 - 19

(3) Charging

Charging is effected by applying a DC minus voltage to the charge roller that is in contact with the image drum surface.

Power supply

Image drum

Charge roller

(4) Exposure

Power supply

Light emitted from the LED head irradiates the image drum surface with negative charges. The surface potential of the irradiated part of the image drum drops, thereby forming an electrostatic latent image associated with the image signal.

LED head

Charge roller

Image drum

LED head

Paper

Image drum

2 - 20

(5) Developing

Toner is attracted to the electrostatic latent image on the image drum surface to convert it into a visible toner image. Developing takes place at the contact between the image drum and the developing roller.

1 As the toner supply roller rotates while rubbing on the developing roller, a friction charge

is generated between the developing roller and the toner, allowing the toner to be attracted to the developing roller. (The developing roller surface is charged positive and the toner, negative.)

Doctor blade

Charge roller

Toner supply roller

Image drum

Developing roller

2 The toner attracted to the developing roller is scraped off by the doctor blade, forming

a thin coat of toner on the developing roller surface.

3 Toner is attracted to the exposed part (low-potential part) of the image drum at the

contact between the image drum and the developing roller, making the electrostatic latent image visible.

2 - 21

(6) Transfer

The transfer roller is composed of conductive sponge material and is designed to make the image drum surface and the paper closely into contact.

Paper is placed over the image drum surface, and a positive charge, opposite in polarity to the toner, is applied to the paper from its reverse side.

The application of a high positive voltage from the power supply to the transfer roller causes the positive charge induced to the transfer roller surface to be transferred to the paper at the contact between the transfer roller and the paper. As a results, toner charged negative that is attracted to the image drum surface is transferred to the upper side of the paper by the positive charge on the lower side of the paper.

Image drum

Transfer roller

Paper

Power

supply

2 - 22

(7) Fusing

After the end of the transfer, the unfused toner image is fused on the paper under heat and pressure as it passes between the heater roller and the back-up roller. The heater roller with a Teflon coating incorporates a 750W heater (Halogen lamp), which heats the heat roller.

A thermistor which is in contact with the heater roller regulates the heater roller at a predetermined temperature (about 180 ~ 200°C). A safety thermostat cuts off voltage supply to the heater by opening the thermostat in the event of abnormal temperature rises.

The back-up roller is held under a pressure of 5 kg from the pressure spring at each side.

Heater

Paper

Separation Claw

Thermistor

Heater Roller

Roller-BK

Pressure Spring

2 - 23

(8) Cleaning

After the end of the transfer, residual toner on the image drum is attracted to the cleaning roller temporarily by static electricity to clean the image drum surface.

Image Drum

Cleaning Roller

Power

Supply

Transfer Roller

(9) Cleaning of rollers

The charge roller, transfer roller and cleaning roller are cleaned in the following cases:

• In warming up at power-on time

• In warming up after the cover is opened and closed

• When the number of accumulated sheets is 10 or more and the printout operation ends Changes in bias voltage applied to each roller move adhesive toner from the roller to the

image drum and return it to the developer.

2 - 24

2.3.4 Revision of LED Head Illumination An LED correcting head, which is capable of correcting the illumination of the LED for each dot,

is being used in this printer. LED illumination correction function of 16 steps is carried out by using an EEPROM which is installed in the LSI that maintains the LED illumination correction values, and an LED correction drivers together as a pair.

The LED correcting head consists of the correction control LSI , LED drivers , and an LED array. The block diagram of the LED correcting head is shown below.

(1) Both sides wire-bonding head

Correction Control

LSI

EEPROM

STRB4-N STRB3-N

DATA 3 DATA 2

LED Driver LED Driver

From

CPU

LOAD

CLOCK

STRB2-N STRB1-N

DATA 1 DATA 0

LED LED LED LED LED LED LED

LED Driver LED Driver

LED Array

In OKIPAGE 20/ OKIPAGE 20n, the correction control of LED head is excuted direction by CPU. The procedure is as follows

(i) LED head is set to the correction control read mode and all correction data stored

in EEPROM within the correction control LSI are read by CPU, and stored temporarily in the memory.

(ii) Next, LED head is set to the correction control direct mode and the correction data

stored temporarily in the memory is transferred directly to the LED driver.

2 - 25

(i) Read of correction data

CLOCK

LOAD

DATA 3~0

STRB1-N

STRB2-N

STRB3-N

STRB4-N

Mode setting

RD Mode enabled

RD Mode set

250ns min

High-Z

data1 data3

correction data1

correction data2 correction data 4992

data2 data4

1000

dummy cycle

8 clocks

RD cycle

8 clocks

RD cycle

8 clocks

Head data read Correction data read

Total 19992 clocks

RD cycle

8 clocks

RD cycle

8 clocks

correction data 4991

2 - 26

01100

CLOCK

LOAD

DATA 3~0

STRB4~1

Mode setting

Total 2496 clocks

Correction data 1

Correction data 4991

Correction data 4992

Correction data 2

Correction data 4

Correction data 3

DIRECT Mode enabled

DIRECT Mode set

DIRECT

250ns min

(ii) Transfer of correction data to head driver correction data

2 - 27

(2) One side wire-bonding head

DATA 3 DATA 2 DATA 1 DATA 0

From

CPU

CLOCK

LOAD

STRB4-N STRB3-N STRB2-N STRB1-N

Correction Control

LSI

EEPROM

LED Array

LED LED LED LED LED LED LED

LED Driver LED Driver

(i) LED head is set to the correction control read mode and all correction data stored

in EEPROM within the correction control LSI are read by CPU, and stored temporarily in the memory.

(ii) Next, LED head is set to the correction control direct mode and the correction data

stored temporarily in the memory is transferred directly to the LED driver.

2 - 28

(i) Read of correction data

CLOCK

LOAD

DATA 3~0

STRB1-N

STRB2-N

STRB3-N

STRB4-N

Mode setting

RD Mode enabled

RD Mode set

250ns min

High-Z

data1 data3

correction data1

correction data2 correction data 5200

data2 data4

1000

dummy cycle

8 clocks

RD cycle

8 clocks

RD cycle

8 clocks

Head data read Correction data read

Total 20824 clocks

RD cycle

8 clocks

RD cycle

8 clocks

correction data 5199

2 - 29

01100

CLOCK

LOAD

DATA 3~0

STRB4~1

STRB1-N

STRB2-N

STRB3-N

STRB4-N

Mode setting

Total 5200 clocks

Correction data1 Correction data1300

Correction data1301

Correction data2

DIRECT Tp

Ditail figure A-D

A part of A A part of B A part of C A part of D

Tp Tp Tp

Tp > 2µs

Tp Tp Tp Tp

Correction data2600

Correction data2601

Correction data3900

Correction data3901

Correction data5200

more than 1µS

(ii) Transfer of correction data to head driver correction data

2 - 30

The LED driver corrects the LED illumination by controlling the LED current. The LED illumination can be set in 16 steps, with 7 steps in the direction of illumination increase in relation to the standard value, and 8 steps in the direction of decrease. For this reason, the LED correction data is a 4-bit data for each dot.

The relationship between the LED correction data and LED current correction steps with the LED driver used in an LED head is shown below.

LED Correction Data

msb b3

Corretion Data

Correction

lsb b0

Step

+16%

+14%

+12%

+10%

+8%

+6%

+4%

+2%

-2%

-4%

-6%

-8%

-10%

-12%

-14%

Correction

Mode

↑ ↑

Correction by

increasing

illumination

↑ ↑ ↑

No correction

↓ ↓

Correction by

decreasing

illumination

↓ ↓

2 - 31

The printing operation timing chart is shown below.

Normal Mode Printing Timing Chart

CLOCK

LOAD

DATA3~0

STRB1-N

STRB2-N

STRB3-N

STRB4-N

First line printing data sent Second line printing data sent

First line printing

The printing operation is carried out in normal mode. Under ordinary circumstances such as when the power is turned on or when LOAD signal level is low, the normal mode is enabled.

The printing operation is carried out in the following sequence. First, the printing data DATA3 through DATA0 are stored, sequentially shifted, in the shift registers of the LED drivers, by the printing data synchronous clock, CLOCK. Then the printing data stored in shift registers are latched by the high level pulse of LOAD. The latched printing data turns the LEDs on by STRB1N through STRB4-N and actuates printing.

2 - 32

2.4 Paper Jam Detection

The paper jam detection function supervises the paper state at power-on time and during printing. In the event that the following state occurs, this function interrupts the printing process. If any of the following errors is presented, recovery printing will be performed by removing the jammed paper (namely by opening the upper cover, removing the jammed paper and closing the upper cover).

Error Cause of error

Paper input jam • At power-on time, the paper is placed at the inlet sensor.

• After hopping operation is attempted three times, the leading part of the

Paper feed jam • At power-on time, the paper is placed at the paper sensor.

• The leading part of the paper does not reach the paper sensor within a

• The traiding part of the paper does not pass over the paper sensor within

paper does not reach the inlet sensor.

predetermined distance after the paper has reached the inlet sensor.

a predetermined distance after the leading edge of the paper has passed over the paper sensor.

• The leading part of paper does not reach the outlet sensor within a predetermined distance after the paper has reached the paper sensor.

Paper exit jam • At power-on time, the paper is placed on the outlet sensor.

• The paper does not pass over the outlet sensor within a predetermined after the leading part of the paper has reached the outlet sensor.

• The paper size check with the manual feed specified considers the reference size as free size.

Paper size error • The size of the paper is supervised by the inlet sensors 1. It is detected

that the paper does not pass over the inlet sensor 1 within predetermined range of distance.

• The inlet sensor 2 detects that the size of the loaded paper is A4 or larger, or smaller than A4. The detected paper size differs from the paper size set by command or menu.

• The paper size check with the manual feed specified considers the reference size as free size.

2 - 33

2.5 Cover Open

When the stacker cover is opened, the cover open microswitch on the Power Supply Unit (High voltage) is turned off to cut the supply of +30V to the high voltage power supply circuit. As a result, all high-voltage outputs are interrupted. At the same time, the CVOPN signal is sent to the control board to notify it of the off state of the microswitch, and the Main board performs the cover open processing.

2 - 34

2.6 Toner Low Detection

• Composition The device consists of the stirring gear which rotates at a constant rate, the stirring bar and

the magnet on the stirring bar. The stirring bar rotates through the link on the protrusion in the stirring gear.

Magnet

Stirring Bar Stirring Gear

• Operation

Toner Low is detected by monitoring the time interval of the encounter of the magnet set on the sensor lever and the magnet on the stirring bar.

Protrusion

Stirring Gear Section

Operation during toner full state

• The stirring bar rotates due to the interlocking

with the stirring gear.

• Even when the magnet on the stirring bar

reaches the maximum height, since the other side is being dipped in the toner, the stirring bar is pushed by the stirring gear.

Operation during toner low state

• When the stirring bar reaches the maximum

height, since there is no resistance provided by the toner on the other side, it falls to the minimum height due to its own weight. Because of this, the time interval during which it is in encounter with the magnet of the sensor lever becomes long. By monitoring this time interval, toner low can be detected.

Stirring Bar

Sensor Lever

Toner Sensor

Stirring Bar

Sensor Lever

2 - 35

TONER FULL state

TNRSNS

TONER LOW state

TNRSNS

• When the toner low state is detected 2 times consecutively, Toner Low is established.

• When the toner full state is detected 2 times consecutively, Toner Low is cancelled.

• When there is no change with the toner sensor for 2 cycles (2.727 sec. x 2) or more, then the

Toner Sensor Alarm is activated.

t1 < 2.727/4

2.727 SEC.

t1 > 2.727/4

• The toner sensor is not monitored while the drum motor is in halt.

2 - 36

2.7 Stacker-full Detection

The sensor (interlocked with the lever) at the paper outlet to the stacker detects a stacker-full state (about 250 sheets) and stops printing of the ensuing pages.

2.8 Page Size Detection

The four tab pieces are driven according to the setting position of the paper guide through the cam interlocked with the paper guide of the paper cassette.

When the paper cassette is inserted into the printer, the state of the tab pieces is detected by the microswitch to recognize the paper size.

State of Microswitches Paper size

SW1 SW2 SW3 SW4

0111Letter 0101Executive 0011A4 1110Legal 14 1011Legal 13 1101B5 1100A5 1001A6 (Not available)

2.9 PostScript ROM module (BOARD-MSM-2 or BOARD-FSL-2)

PostScript ROM module is mounted on SIMM socket (FSIMM1). The PostScript ROM module consists of program/font ROM's, an EEPROM.

(1) Program/font ROM's

The program/font ROM's store the PostScript Level II program and its fonts. BOARD-MSM-2 consists of Mask ROM. BOARD-FSL-2 consists Flash ROM. Mask ROM and Flash ROM is used as the program/ font ROM's.

(2) EEPROM

The EEPROM has a 4-kbit capacity and stores the PostScript's menu settings.

(3) Emulation

PostScript Level 2.

2 - 37

3. PARTS REPLACEMENT

The section explains the procedures for replacement of parts, assemblies, and units in the field. Only the removal procedures are explained here. Reverse the procedure for the installation.

3.1 Precautions for Parts Replacement

(1) Before starting parts replacement, remove the AC cable and interface cable.

(a) Remove the AC cable in the following procedure:

i) Turn off ("o") the power switch of the printer ii) Disconnect the AC inlet plug of the AC cable from the AC receptacle. iii) Disconnect the AC cable and interface cable from the printer.

(b) Reconnect the printer in the following procedure.

i) Connect the AC cable and interface cable to the printer. ii) Connect the AC inlet plug to the AC receptacle. iii) Turn on ("l") the power switch of the printer.

Disconnect

OFF

(2) Do not try disassembly as long as the printer is operating normally. (3) Do not remove unnecessary parts: try to keep disassembly to a minimum. (4) Use specified service tools. (5) When disassembling, follow the determined sequence. Otherwise, parts may be damaged. (6) Since screws, collars and other small parts are likely to be lost, they should temporarily be

attached to the orginal positions.

(7) When handling ICs such as microprocessors, ROM and RAM, and circuit boards, do not wear

gloves that are likely to generate static electricity.

Connect

(8) Do not place printed circuit boards directly on the equipment or floor.

3 - 1

[Service Tools] Table 3-1 shows the tools required for field replacement of printed circuit boards and units.

Table 3-1 Service Tools

No.

7 1

No. 1-100 Philips screwdriver

No. 2-200 Philips screwdriver, Magnetized

No. 3-100 screwdriver

No. 5-200 screwdriver

Digital multimeter

Pliers

Handy cleaner

LED Head cleaner P/N 4PB4083-2248P1

Connector remover P/N 4PP4076-5395P1

Q' ty Place of use RemarksService Tools

2~2.5 mm screws

3~5 mm screws

Cleans LED head

Disconnect connector

Holder-TR Eject P/N 40596701

3 - 2

For removing ROLLER-Transfer

3.2 Parts Layout

Plate-Shield

Frame-OP panel Assy

Cover-Side(I/F)

Face-up stacker Assy

Cover-Rear

ROLLER-Transfer

Cover-Frame

Main Control Board

(Board-AAA)

Cover-Side(L) Assy

Contact Assy

Cover-Side(R)

Manual Feed Assy

Base Unit

CASE Assy-Cassette

Figure 3-1

3 - 3

Feed Unit-FRONT

HEAT-Assy

Toner Cartridge

(Type 7)

ID Unit

(Type 7)

Motor-Main

ROLLER

Assy-Feed

GUIDE-Assy-Eject

LED HEAD

Stacker Cover

FRAME-Main

DC Fan Motor

Figure 3-2

3 - 4

FILM-Insulation

Power Supply Unit (120V/230V)

Power Supply Unit (High Voltage)

FRAME Assy-Hopping

ROLLER Assy-Feed

GUIDE Assy-Cassette(L)

Board PXC

GUIDE Assy-Cassette(R)

PLATE-Bottom

Figure 3-3

3 - 5

3.3 How to Change Parts

Printer Unit

Face-up Stacker Assy

Contact Assy

OP Panel Assy

Paper Cassette,

ROLLER Ass-Feed,

ROLLER-Assy-Hopping

Transfer Roller/TR Gear/

TR Bearing

(3.3.1)

(3.3.2)

(3.3.4)

(3.3.19)

(3.3.21)

DC fan motor

HEAT Assy

Board-AAA

Feeder Unit-Front

Frame Assy-Separation

(3.3.3)

(3.3.14)

(3.3.5)

(3.3.10)

(3.3.20)

Roller Assy-BK

Stacker Assy, Damper Arm

, Cover Rear

Roller Assy-Regist

Motor-Main

Roller Assy-Feed

(3.3.16)

(3.3.6)

(3.3.11)

(3.3.12)

(3.3.17)

Sensor Stacker Full

Cable Cover

Damper

LED Head

Guide Assy-Eject

EP Lock Shaft

Lever Assy-Out Sensor

Toner Sensor Lever

Paper Sensor Lever

Inlet Sensor Lever

Power Supply Unit

Lever-Paper end &

Paper near end

(3.3.7)

(3.3.8)

(3.3.9)

(3.3.18)

(3.3.13)

(3.3.22)

(3.3.23)

(3.3.24)

(3.3.25)

(3.3.26)

(3.3.27)

(3.3.28)

Roller Feed (C)

Gudie Assy-Cassette(L)

Gudie Assy-Cassette(R)

(3.3.15)

(3.3.29)

(3.3.30)

This section explains how to change parts and assemblies appearing in the disassembly diagram below.

3 - 6

3.3.1 Face -up Stacker Assy (1) Turn off the AC Power Switch and unplug the AC Power Cord from the outlet. (2) Disconnect the Interface Cable 1. (3) Open the face-up stacker assy 2, unhook the right and left projections, and then remove

the face-up stacker assy 2.

3 - 7

3.3.2 Contact Assy (1) Open the stacker assy 1 and unscrew 2 screw 2 to remove the assy -side (L)3. (2) Unscrew 2 screws 4 and remove the plate (contact) 5 and contact Assy 6.

Note! Don’t deform the electrode plates of the contact assy 6.

Unlock this part before removing

3 - 8

3.3.3 DC Fan Motor (1) Remove the cover assy-side (L). [See 3.3.2 (1)]

(2) Remove the DC fan motor 1 by pulling out the connector of DC fan motor 1.

3 - 9

3.3.4 OP Panel Assy (1) Disconnect the Interface cable 1. (2) Open the stacker assy 2, unscrew 2 screws 3 and remove the cover side (I/F) 4. (3) Remove 2 screws 5 and flexible cable 6 to remove the operator panel assy 7.

3 - 10

3.3.5 Board-AAA (1) Remove the operator panel assy and cover side (I/F). [See 3.3.4] (2) Unscrew 2 screws 1 and remove the cover side (R) 2. (3) Unscrew 2 screws 3 and remove plate-shield 4. (4) Unscrew 3 screws 5 and 2 screws 6, unplug all the connectors 7 , and remove Board-AAA

3 - 11

3.3.6 Stacker Assy, Damper Arm, Cover Rear (1) Remove the face-up stacker assy. [See 3.3.1] (2) Remove the cover-side (L). [See 3.3.2 (1)] (3) Remove the OP panel assy. [See 3.3.4] (4) Remove the Board-AAA. [See 3.3.5] (5) Loosen 2 screws, unlock the both sides latches and remove the cover rear A. (6) Unscrew 2 screws 1 and cover frame 2. (7) Unscrew 3 screws 3 and remove the plate assy-side (R) 4. (8) Remove the lever back up release 5 and unlock the engagement of the projection on the

right side of gear at the right side of stacker cover.

(9) Remove a screw 6 and washer 7, and then remove the stacker assy 8.

(At this time, the damper arm 9 can also be detached simultaneously.)

3 - 12

3.3.7 Sensor Stacker Full (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the Stacker assy. [See 3.3.6] (3) Remove four screws 1. Remove stacker mount 2 by releasing the tabs at position 2A . (4) Remove Sensor stacker full 3 by releasing speading the plastic tabs on each side of sensor

Assy 3 and lifting switch from cover.

3 - 13

3.3.8 Cable cover (guide film) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the stacker Assy. [See 3.3.6] (3) Unscrew 2 screws 1 release tabs at portion 1A . Remove cable cover 2, guide film 3.

Note: Use care when replacing cable cover. Do not pitch, crimp, or cut cables or

protective sheet.

3 - 14

3.3.9 Damper (1) Remove the damper arm. [See 3.3.6]

(2) Unscrew 2 screws 1 and remove the two damper 2.

3 - 15

3.3.10 Feeder Unit-Front

(1) Open the manual feed assy 1 and release both right and left parts by pulling out the

engagements on the lower part.

(2) Stand the manual feed assy 1 on end and unhook the engagements with both right and left

manual feed hopper stays.

(3) Remove the OP panel assy. [See 3.3.4]

(4) Unscrew 5 screws 2 and remove the feeder unit-front 3.

3 - 16

3.3.11 Roller Assy-Regist (1) Remove the feeder unit-front. [See 3.3.10] (2) Remove an E-ring 3, gear assy-clutch 4, and four screws 1 in this order, and lifting out the

roller assy-regist 2.

3 - 17

3.3.12 Motor -Main (1) Remove the stacker assy. [See 3.3.6] (2) Remove the feeder unit-front. [See 3.3.10]

(At this point, the manual feed assy has not to be removed.) (3) Remove the DC fan motor. [See 3.3.3] (4) Remove the contact assy. [See 3.3.2] (5) Remove the plate-FG (F) 1. (6) Remove the TR gear 2 and roller transfer 3.(Use Holder-TR Eject F for the removal.) (7) Unscrew 7 screws 4 and remove the main frame 5. (8) Unlock latches at two points of the lever back up release 6 and pull out it in right direction. (9) Unhook the EP lock spring 7 and remove the EP lock lever 8. (10) Take off the E ring 9 and remove the plate-FG (1st ) 0 and gear assy-clutch A.

(11) Unlock 2 latches to remove the motor assy-main B and idle gear C.

(12) Unscrew 2 screws D and remove the motor -main E .

3 - 18

Latch

View A

3 - 19

3.3.13 Guide Assy-Eject (1) Remove the lever back up release. [See 3.3.12(8)]

(But the roller transfer/feeder unit front/plate-FG have not be removed)

(2) Loosen 2 screws 1, unlock the both side’s latches and remove the cover rear 2. [See 3.3.6

(5)]

(3) Unlock the latches on both sides of the guide assy-eject 3 and lifting it out.

3 - 20

3.3.14 Heat Assy (1) Remove the cover assy-side (L). [See 3.3.2 (1)] (2) Unplug the connectors 1, 2. (3) Unscrew 4 screws 3 and remove the heat assy 4 in the direction of the arrow by lifting the

right side first. Note ! • As the heat assy 4 becomes high temperature soon after the power is turned

off, start the work after it cools off sufficiently.

• Carry out a reset of the counter after the replacement. (See Section 4.2)

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3.3.15 Roller feed (C) (1) Remove the guide assy-eject. (See 3.3.13)

(But roller transfer/feeder unit-front/plate-FG(F) have not be removed)

(2) Remove the gear roller (C) 1 and bush 2, warp (a) part of the plate-FG (BK) 3. Take off

the carrier bearing 4 and remove the roller feed (c) 5 in the direction of the arrow.

Note ! Be careful not to deform (a) part of the plate-FG (BK) 3.

(a)

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3.3.16 Roller Assy-BK (1) Remove the heat Assy. [See 3.3.14] (2) Remove the lever back up release. [See 3.3.12 (8)] (3) Unlock the engagement with the plate-FG (BK) 1 and lift out the roller heat assy 2.

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3.3.17 Roller Assy-Feed (1) Remove the feeder unit -front. [See 3.3.10] (2) Remove the roller assy-feed 1 by unlocking a latch.

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3.3.18 LED Head (1) Remove the stacker assy 1. [See 3.3.6] (2) Unplug the PC connector 2 and 2 LED cables 3 from the LED head 4. (3) Open the hooks of the cover stacker 1 in the direction of the arrow and remove the LED head

(4) Pull out the head spring 5 from the post.

Note: Don't remove two LED cable 3 from the PC connector 2.

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3.3.19 Paper cassette, ROLLER Ass-Feed, ROLLER-Assy-Hoppibg (1) Pull out the case assy -cassette 1 from the printer. (2) Remove the ROLLER Ass-Feed 2 and remove the ROLLER-Assy-Hopping 3.

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3.3.20 Frame Assy-Separation (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Pull out the case Assy-Cassette 1 from the printer.[See 3.3.19(1)] (3) Release two locks and remove frame assy-separation 2. (At this time, coil spring 3 is also

remove. Be careful not to lose this spring.)

Insert 1 so as to pass the both

arms of 1 behind two latches inside the alcove of 2 unit.

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3.3.21 Transfer Roller/TR Gear/TR Bearing (1) Open the stacker cover . (2) Unlock the lock by lifting the TR gear 1 to remove the TR gear 1 and roller transfer 2.

(Use the Holder-TR Eject 5 for the removal.) Note ! Don’t place the removed roller transfer directly on the desk and so on. When

placing it, lay a paper and the like under it.

(3) Remove right and left, 2 bearings 3 from the frame-main by sliding them inside while

pushing them. At this time, 2 transfer springs R 4 would be detached simultaneously.

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3.3.22 EP lock shaft

(1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove Frame-Main [See.3.3.12(7)] (3) Remove screw 1. Turn EP lock lever (L) Assy 2 in the direction of arrow A . (4) Remove spring 3. (5) Drop EP lock shaft 4 down and turn in the direction of arrows B and remove it.

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3.3.23 LEVER Assy- Out Sensor (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Press the clamp part of LEVER Assy.- Out Sensor 1. Remove the LEVER Assy.-Out Sensor

1 by pushing it upward from the lower side.

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3.3.24 Toner sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Squeeze the clamp part of toner sensor lever 1 and remove the toner sensor lever 1 by

pushing it upward from the lower side.

3 - 31

3.3.25 Paper sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Squeeze the clamp part of the paper sensor lever 1 and remove the paper sensor lever 1

by pushing it upward from the lower side.

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3.3.26 Inlet sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Squeeze the clamp part of two inlet sensor levers 1. Remove the inlet sensor levers 1

by pushing them downward.

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3.3.27 Power supply unit (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Unscrew 2 screws 1 and remove the BRACKET-AC 2. (4) Unscrew 10 screws 3 and remove the connector 6 remove the Power supply unit [AC-

DC(120/230V)] 4 and Power supply unit (High voltage) 5.

3 - 34

3.3.28 Lever-Paper end & Lever-Paper near end (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the frame main [See 3.3.12(7)] (3) Remove screw 1 and then remove the PLATE-Base 2. (4) Remove two Spacer-Cord(KGPS-5RF) 4 and then remove FILM-Insulation 4. (5) Remove four screws 5 and then remove the FRAME ASS-Hopping 6. (6) Remove the GEAR-Z58 9 and GEAR-Z42 8.

(At this time, the ADF Bearing 0 can also be detached simultaneously.)

(7) Remove the GEAR-Z38 D, ADF Bearing E, ROLLER-Guide F and SHAFT Hopping G and

Bracket-Sub roller R. (At this time, the Kock Pin H can also be detached simultaneously.)

(8) Remove two screws 7 and then remove the SPRING-Release A and then remove the

LEVER-Sub roller B and PLATE-Hopping C.

(9) Remove the GEAR-Planet(Z28) I, Plate-Planet J, BRACKET-Spring (Sub) K and

SPRING-Sub ROLLER L.

(10) Press the clamp part of Lever-Paper end M and Lever-Paper near end N. Remove the

Lever-Paper end M and Lever-Paper near end N by pushing it upward from the FRAME

Hopping R. (11) Remove the Connection Cord-Wire O and TR-23-11-14 R CORE P together. (12) Remove two Photo Sensor Q.

3 - 35

3 - 36

3.3.29 Guide Assy-Cassette (L) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove Frame Main [See 3.3.12(7)] (3) Remove PLATE-Base and FRAME Assy Hopping [See 3.3.28 (5)] (4) Unscrew two screw 1 and then remove Guid Assy-Cassette (L) 2. (5) Remove SPRING-Sheet 3 and then remove LINK-Sheet 4 and pull block 5.

(Pay attention the direction of hook of SPRING-Sheet 3.) (6) Remove spring 6 and then remove cassette stopper 7. (7) Remove screw 8 from LINK-Sheet 4 and then remove link support 9 and Roller-link 0. (8) Remove Earth Plate L A and Plate-Earth (link) B.

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3.3.30 Guide Assy-Cassette (R) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove Frame Main [See 3.3.12(7)] (3) Remove PLATE-Base and FRAME Assy Hopping [See 3.3.28 (5)] (4) Unscrew two screw 1 and then remove Guid Assy-Cassette (R) 2. (5) Remove SPRING-Sheet 3 and then remove LINK Sheet 4 and pull block 5.

Nylon Connector Cord C and TR-23-11-R CORE D. (9) Unscrew two screws E and remove the two Plate Earth (Bottom) F. (10) Unscrew two screws G and remove the Square shaped connector (5-176496-1) H and

Connection Cord Wire I and TR-23-11-R CORE J. (11) Unscrew a screw K and remove the Detector spring L. (12) Unscrew a screw M and remove the Board PXC N.

3 - 38

3 - 39

4. ADJUSTMENT

This chapter explains the adjustment necessary when replacing a part. Adjustment is made by changing a parameter value set in EEPROM on the controller PCB. A parameter is able to set with the key operation on the operator panel. This printer has three kinds of the maintenance mode, it is required to select one of the maintenance mode necessary when replacing a part.

4.1 Maintenance Modes And Functions

• User maintenance mode

To enter the user maintenance mode, turn on the POWER switch while pressing the MENU key.

[Function] There are 13 functions as follows.

• Menu reset • Y adjust

• Hex dump • Duplex Adjust

• Drum counter reset • Select paper source command parameter

• Resource Save (Second, Third, Front Tray)

• Receive Buffer Size • Page placement

• Operator panel menu disable • Setting

• X adjust • Cleaning cycle

• System maintenance mode

Note:

This mode is used only by service persons and it should not be released to the end-

users.

To enter the system maintenance mode, turn on the POWER switch while pressing the RECOVER key.

[Function] There are 8 functions as follows.

• Page count display

• Page count printing enable/disable

• Rolling ASCII continus prinitng

• RS232C LOOP TEST

• EEPROM reset

• HSP ERROR recovery

• HSP ERROR count display

• HSP ERROR count reset

• SIDM enable/disable

4 - 1

• Engine maintenance mode

Note:

This mode is used only by service persons and it should not be released to the end-

users.

To enter the engine maintenance mode, turn on the POWER switch while pressing the FORM FEED key and ENTER key.

[Function] There are 19 functions as follows.

• Head type setting

• Head drive time setting.

• Head drive time setting at Auto head type

• Head strobe time at 600 x 1200 dpi

• Printing start position setting

• Drum counter total display

• Drum count display

• Setting of standard paper feed length

• Setting of front feeder paper feed length

• Setting of second tray paper feed length

• Selection of second tray feeder download table

• Setting of third tray paper feed length

• Selection of third tray feed download table

• Setting of Multi-purpose feeder paper feed length

• Selection of Multi-purpose feeder download table

• Setting of duplex feed length

• Fuser count indication

• Fuser count reset

• Engine reset

4 - 2

4.1.1 User maintenance mode

• To enter the user maintenance mode, turn the power supply ON while pressing the Menu

key.

• This mode uses the menu for function selection.

• The user maintenance mode provides the following functions: (1) Menu reset

• All settings for Menu level-1 are reset to the factory default values. The menus for all executable emulations including options are reset to the factory default values.

• The operation mode starts automatically upon completion of resetting.

(2) Hex dump

• The data received from the host is dumped in hexadecimal notation to the printer.

• Printing is activated automatically when the received data exceeds one page. If the received data is less than one page, printing can be activated manually be pressing the Form Feed key after selecting the OFF LINE mode by pressing the ON-LINE key. (Automatic activation of printing even when the received data is less than one page by selecting the Auto Eject function on the menu.)

• To exit from this mode is turning the power OFF.

(3) Drum counter reset

• This function resets the drum life data when the user replaces the image drum unit.

• The operation mode starts automatically upon completion of resetting.

(4) Resource Save

• Set the storage area size of resource to be stored between PCL and Postscript.

(5) Receive Buffer Size

• Set the receiving buffer.

(6) Operator panel menu disable

• This function is for enabling and disabling the operator panel menu functions (Menu 1, Menu 2, Tray Select, Copies and Paper Size).

(7) X ADJUST

• This function is used to adjust the printing start position within the range of ±2 mm in

0.25 mm steps in the X direction.

(8) Y ADJUST

• This function is capable to adjust the printing start position within the range of ±2 mm in 0.25 mm steps in the Y direction.

4 - 3

(9) Duplex adjust

• The function which performs a correction in Y direction towards the sheet supplied from the tray in double-sided printing.

(10) Select paper source command parameter (Second tray)

• The function which sets the parameter selecting the second tray by paper source command (ESC & N # H) on PCL.

(11) Select paper source command parameter (Third tray)

• The function which sets the parameter selecting the third tray by paper source command (ESC & N # H) on PCL.

(12) Select paper source command parameter (Front tray)

• The function which sets the parameter selecting the front tray by paper source command (ESC & N # H) on PCL.

(13) Page placement

• The function which aligns a printing image to the right.

(14) SETTING

• This function is used to adjust to improve print quality.

-2 Rough/thick paper, Low temperature/humidity and/or blockly faded print appeared.

-1

Nomal media/enviroumental conditions.

Rough papers, high temperature/humidity and/or snowy print of high density pattern.

(15) Cleanig cycle

• Set the page interval to perform Cleaning Sequence. When stains build up especially in using rough papers. Change the cleaning cycle.

The shorter the cycle is set, the less the stains become. Normal : Each 20th page (default)

Middle : Each 10th page High : Each 3th page

4 - 4

User maintenance mode menu system

Menu key

Power ON

LCD display

USER MNT

Press the Menu key.

MENU RESET

Press the Menu key.

HEX DUMP

Press the Menu key.

DRUM CNT RESET

Press the Menu key.

RSRC SAV

Press the Menu key.

REC BUFF

Press the Menu key.

OP MENU ENABLE *

Press the Menu key.

X-ADJUST 0 mm*

Press the Menu key.

Press the Enter key.

Press the or key.

MENU RESET'NG

ON-LINE .HEX

DRUM CNT RESET'NG

AUTO* OFF 400KB 900KB

1.6MB

2.5MB

3.6MB

4.9MB

6.4MB

8.1MB

10.0MB

12.1MB

14.4MB

16.9MB

19.6MB

22.5MB

AUTO* 8KB 20KB 50KB 100KB 1MB

DISABLE

0 mm * + 0.25 mm + 0.75 mm + 1.00 mm + 1.25 mm + 1.50 mm + 1.75 mm + 2.00 mm

- 2.00 mm

- 1.75 mm :

- 0.25 mm

After the end of processing

End of processing is performed by the power supply OFF.

After the end of processing

Writing into the EEPROM is performed when the Enter key is pressed.

Writing into the EEPROM is performed when the Enter key is pressed. (0.25 mm intervals)

ON-LINE***

4 - 5

Y-ADJUST 0 mm*

DUP ADJ

2ND TRAY

3ND TRAY

FRONT

PLACE PG

SETTING 0 *

Press the Menu key.

CLN CYCL

Press the Menu key.

INITIALIZING

Press the or key.

Press the Menu key.

Press the or key.

Press the Menu key.

Press the or key.

Press the Menu key.

Press the or key.

Press the Menu key.

Press the or key.

Press the Menu key.

Press the or key.

Press the Menu key.

Press the ON LINE key.

Press the or key.

0 mm * + 0.25 mm + 0.75 mm + 1.00 mm + 1.25 mm + 1.50 mm + 1.75 mm + 2.00 mm

- 2.00 mm

- 1.75 mm :

- 0.25 mm 0 mm *

+ 0.25 mm + 0.50 mm + 0.75 mm + 1.00 mm : + 2.00 mm

- 2.00 mm

- 1.75 mm :

- 0.25 mm

1 2 3 : 5* : 16

1 2 3 : 9* : 16

1 2 3 4* : 16

CENTER* LEFT

+2 +1 0 *

-1

- 2 NORMAL*

MIDDLE HIGH

Writing into the EEPROM is performed when the Enter key is pressed. (0.25 mm intervals)

Writing into the EEPROM is performed when the Enter key is pressed.

ON-LINE ***

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4.1.2 System maintenance mode

• The system maintenance mode is set when the power is turned ON while pressing the Recover key.

• This mode adopts the menu for function selection.

• The system maintenance mode is provided with the following functions:

(1) Page count display

• The total number of pages counted at the engine is displayed on the LCD.

(2) Page count printing enable/disable

• This function selects whether to include (enable) or exclude (disable) the total number of printed pages counted at the engine at the time of menu printing.

(3) Rolling ASCII continuous printing

• The rolling ASCII pattern is printed continuously for various engine tests.

• Press the ON-LINE key to cancel this mode.

(4) RS232C LOOP TEST

• Performs a loop test of RS 232C.

(5) EEPROM reset

• All EEPROM areas including Menu level-2 to the factory default values.

• The following items are excluded * Head drive time setting * Fine adjustment of printing start position * Standard tray paper feed amount setting

• Transition to the operation mode occurs upon completion of resetting.

• Press the Menu key to update each category. The operation returns to the first category after updating the last category.

(6) HSP ERROR recovery

• Select HSP ERROR recovery function either recover or stop.

(7) HSP ERROR count

• Display total HSP ERROR count.

4 - 7

(8) HSP ERROR count reset

• Reset the HSP ERROR counter.

(9) SIDM enable/disable

• If it's selected disable, cannot select SIDM emulations by Menu.

4 - 8

OKI PAGE 20 Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

CONTENTS

1. CONFIGURATION

2. OPERATION DESCRIPTION

3. PARTS REPLACEMENT

4. ADJUSTMENT