OKI PAGE 16n Service manual

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-COM).......................................................................... 2-3

2.2 Power/Sensor Board.................................................................................................. 2-7

2.3 Relay/Driver Board (AOLC board)............................................................................. 2-9

2.4 Electro-photographic Process.................................................................................... 2-10

2.4.1 Electro-photographic process mechanism................................................... 2-10

2.4.2 Electro-photographic process....................................................................... 2-12

2.4.3 Process operation descriptions.................................................................... 2-15

2.4.4 Revision of LED Head Illumination............................................................... 2-24

2.5 Paper Jam Detection................................................................................................. 2-28

2.6 Cover Open................................................................................................................ 2-29

2.7 Toner Low Detection.................................................................................................. 2-30

2.8 Stacker-full Detection................................................................................................. 2-32

2.9 Page Size Detection.................................................................................................. 2-32

2.10PostScript Board (BOARD-PSBA) (Option)............................................................... 2-32

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................................................................................................. 3-7

3.3.1 Rear cover, side cover (L) Assy, face-up stacker Assy, and I/F cover Assy. 3-8

3.3.2 Contact Assy................................................................................................ 3-9

3.3.3 DC fan motor................................................................................................ 3-10

3.3.4 Manual feed hopper Assy............................................................................. 3-11

3.3.5 Side cover (R) (operator panel Assy)........................................................... 3-12

3.3.6 Earth plate BK (R) (BOARD-PSBA, BOARD-COM)..................................... 3-13

3.3.7 Stacker cover Assy, damper arm, and washer............................................. 3-14

3.3.8 Damper......................................................................................................... 3-15

3.3.9 Stacker full sensor Assy............................................................................... 3-16

3.3.10Cable cover (cable guides A and B)............................................................. 3-17

3.3.11Eject roller Assy............................................................................................ 3-18

3.3.12Paper supply guide D................................................................................... 3-19

3.3.13Separator F................................................................................................... 3-20

3.3.14Front feeder roller Assy................................................................................ 3-22

3.3.15Hopping motor.............................................................................................. 3-23

3.3.16Front feeder paper end sensor..................................................................... 3-24

3.3.17Main chassis unit.......................................................................................... 3-25

3.3.18Registration roller......................................................................................... 3-27

3.3.19Drum motor................................................................................................... 3-28

3.3.20Idle gear........................................................................................................ 3-30

3.3.21Fusing Assy.................................................................................................. 3-31

3.3.22Fuser pressure roller.................................................................................... 3-32

3.3.23EP lock shaft................................................................................................. 3-33

3.3.24Hopping roller Assy...................................................................................... 3-34

3.3.25Outlet sensor lever....................................................................................... 3-35

3.3.26Toner sensor lever........................................................................................ 3-36

3.2.27Paper sensor lever....................................................................................... 3-37

3.3.28Inlet sensor lever.......................................................................................... 3-38

3.3.29Insulator........................................................................................................ 3-39

3.3.30Paper end lever............................................................................................ 3-41

3.3.31Guide rail (L) Assy........................................................................................ 3-42

3.3.32Guide rail (R) Assy....................................................................................... 3-44

3.3.33Cover Frame................................................................................................. 3-46

3.3.34LED head...................................................................................................... 3-47

3.3.35Separator Assy............................................................................................. 3-48

3.3.36Transfer roller............................................................................................... 3-49

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.......................................................................... 4-5

4.1.3 Engine maintenance mode........................................................................... 4-8

4.1.4 EEPROM initialization.................................................................................. 4-12

4.2 Adjustment When Replacing A Part........................................................................... 4-13

4.2.1 Setting of LED head drive time..................................................................... 4-13

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

4.2.3 Destination setting........................................................................................ 4-17

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

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..................................................................... 6-13

6.5.3 Image troubleshooting.................................................................................. 6-32

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

B High Capacity Second Paper Feeder.................................... B-1

C Multi Feeder............................................................................. C-1

D LocalTalk Serial Interface....................................................... E-1

(Available only when a PostScript board is mounted.)

1. CONFIGURATION

1.1 System Configuration

OKIPAGE16n consists of control and engine blocks as the standard configuration (See Figure

1-1.)

In addition, the following options are also available.

Printer

AC IN

230/240V

PC etc.

Centronics

Parallel interface

(Bidirection)

LOCAL TALK (Available only when  a PostScript board  is added.)

LAN etc.

Main control

OKI HSP

interface board

(Option)

Operator 

panel

Power/ Sensor

Board

DC Fan

Face down

stacker

LED head Drum motor  Registration motor Hopping motor

Paper tray

Paper size 

detection switch

Face up

stacker

Printer 

Mechanism

I/D unit

Toner Cartridge

Front Feede

Extension RAM

(Option)

PostScript 

board

(Option)

: Paper feeding : Singal flow

Figure 1-1

1 - 1

High Capacity Second Paper

Feeder

(Option)

*: Consumables

: produced by third vender

Multi Feeder

(Option)

1.2 Printer Configuration

The printer unit consists of the following hardware components:

• Electro-photographic processor

• Paper feeder

• Controller

• Operator panel

• Power/sensor board Figure 1-2 shows the printer unit configuration.

Face-up Stacker Assy

Rear Cover

Eject Roller Assy

Side Cover (L) Assy

Stacker Cover Assy

Operator Panel Assy

I/F Cover Assy

Fusing Assy

Front Feeder Unit

Contact

Assy

Base Unit

I/D Unit

Figure 1-2

1 - 2

1.3 Optional Configuration

The options below are available for use with OKIPAGE16n. They are sold separately from

the printer unit.

(1) Multi Feeder

(2) High Capacity Second Paper Feeder

1 - 3

(4) RAM module (72 pin SIMM, 1MB/2MB/4MB/8MB/16MB/32MB)

• 16MB RAM module

• 8MB RAM module

(5) PostScript board

1 - 4

1.4 Specification

(1) Type Desk top (2) External dimensions Height 10.6” (270 mm)

(excludes protruding Width 14.4” (366 mm)

Portion) Depth 16.9” (430 mm) (3) Weight 15.2 kg (33.5 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 –A4 –A5 –B5 –A6

• 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

(6) Printing speed First print: 10 sec.

Continuous print: 16 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 (10)Power input 120 VAC + 5.5%, –15% (ODA)

230/240 VAC + 10%, –14% (ODA/OEL)

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(11) Power consumption Peak: Approx. 600W

Typical Operation: Approx. 220W Idle: Approx. 100W Power save mode: Approx. 20W

(12) Temperature and humidity

In operation Power off mode During Storage Unit

Temperature 50 - 90 32 - 110 14 - 110

(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

(25) (26.8) (

35.6 35.6 (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

(

32 28

Operation rang

20 80

Humidity (%)

(13) Noise During operation: 50 dB (A) or less

At standby: 45 dB (A) or less Power save mode: 43 dB (A) or less

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

Image drum cartridge 30,000 (at continuous printing)

18,000 (3 page/job) 11,000 (1 page/job)

1 - 6

1.5 Safety Standards

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

Certification Label

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

OKIPAGE16n consists of a main control board, a power supply/sensor board, a driver board, 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 OKIPAGE16n block diagram.

2 - 1

ROM SRAM

Z80181

DS8925

LS374

PostScript Board (BOAD-PSBA) (Option)

EEPROM

ROM

* LOCAL TALK interface

Parallel  Interface

OKI HSP interface (option)

Inlet sensor 1

Main  Control  Board (BOARD-COM)

ROM

SIMM

(Option)

D RAM

+8V

-8V

+5V

+30V

CPU

LSI

Relay/Drive Board (AOLC-PCB)

Heat on

DRIVER

EE PROM

LED head

Operator panel

2nd tray

Envelope tray

Home micro switch

Stacker full sensor

Paper end sensor

Hopping motor

AOLS-

(Option)

Paper size detection switch



AC-IN

Outlet sensor

Inlet sensor 2

Paper sensor

Paper out sensor

Toner sensor

Filter circuit

Power / Sensor board

Low voltage generation circuit

Heat on

LSI

Cover open MS

DRIVER

High voltage generation circuit

Driver

+5V

CH TR

DB SB

FAN

TH1

TH2

Charge roller Transfer roller Developing roller Toner supply roller Cleaning roller

Heater

* Available only when a PostScript board is add

Figure 2-1 OKIPAGE16n block diagram

2 - 2

Registration  motor

Drum motor

DC FAN

Thermistor

2.1 Main Control Board (BOARD-COM)

The control board consists of an one chip CPU, LSIs, 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, 32-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 ROM, DRAM and I/O device Bus controller DRAM controller

DMA controller Transfer of image data from DRAM to OST LSI

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 operator panel, EEPROM, and options

I/O port Inputting/outputting of sensor, signal and motor signal

Option I/O interface Control of OKI HSP interface

(2) Program/font ROM's

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

2 - 3

(3) DRAM's

2-Megabyte DRAM (4 Mbit DRAM x 4) is mounted as resident memory to be used for storing the program and providing various buffers. This DRAM is expandable up to 66 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 (MBCE31701-040FP-BND)

This LSI is used as a peripheral device of the CPU and performs smoothing compensation (OST) of print image data (300 dpi and 600 dpi). In addition, it transfers serially bit image data for each dot line to the LED head.

2 - 4

(6) Host interface

This printer has the following interfaces to the host.

• Centronics bidirectional parallel interface

• OKI HSP interface (Option)

• LocalTalk interface (Option. See 2.10 for details.) 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.

(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) OKI HSP interface (Option)

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.

2 - 5

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.

Printer

Network, etc

Control board

OKI HSP 

interface

LAN 

expansion board

Fig. 2-2

(For the electrical/physical characteristics of the OKI HSP interface, see the OKI HSP interface

technical manual.)

(7) RAM module

• Pin layout

1363772

• Basic specification

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

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

- Capacity: 1, 2, 4, 8, 16 or 32MB

- Parity: None

2 - 6

2.2 Power/Sensor Board

The power/sensor board 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

–8 V Local Talk Line 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

CH -1.30 KV Voltage applied to charging roller

DB -240 V/+300 V Voltage applied to developing roller

SB -360 V/450 V Voltage applied to toner supply roller

TR +4 KV/-1.3 kV Voltage applied to transfer roller Variable

CB +400 V Voltage applied to clearimng roller

(3) Photosensor

The photosensor mounted on this power/sensor board supervises the paper running state during printing.

2 - 7

Figure 2-3 shows the sensor layout diagram.

Paper running direction

Exit roller

Outlet sensor

Heat roller

Transfer roller

Sensor

Inlet sensor 1

Inlet sensor 2

Toner sensor

Inlet sensor 1

Inlet sensor 2

Paper sensor

Registration roller

Paper end sensor

Hopping

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.

Sensing state

ON: Paper exists. OFF: No paper exists.

ON: A4 or larger OFF: Smaller than A4

Paper sensor

Outlet sensor

Paper end 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.

Detect the end of the paper.

Detects the lack of toner.

2 - 8

ON: Paper exists. OFF: No paper exists.

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

2.3 Relay/Driver Board (AOLC board)

This board relays signals between the Control board and the Power/Sensor board and includes

the registration motor and drum motor driver IC.

2 - 9

2.4 Electro-photographic Process

2.4.1 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 Feeder

Hopping Roller

Hopping Motor

Registration Motor

LED Head

Fuser

Face Up

Stacker

Drum Motor

Image Drum Unit

Figure 2-4

2 - 10

(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) Registration 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 registration roller.

(4) Drum motor

This drum motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from the control board and is the main motor of this mechanism.

(5) 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.

(6) 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 ~ 188°C) 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 - 11

2.4.2 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 - 12

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

Charging

blade

Doctor

Inlet sensor

roller

Developing

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

roller

Paper 

eject

Paper 

(Face down)

Power

supply

roller

Charger

Power

supply

eject

roller

Paper

Figure 2-5

2 - 13

Cleaning

path 

Paper 

selector

Paper

roller

eject

(Face up)

Fusing

Outlet sensor

Fusing pressure

Heater roller

Paper eject Fusing Cleaning Transfer

Feed stopIN Sensor OFF

OUT Sensor

OFF

Papaer Sensor OFF

PMON-N

RMON-N

INSNS

DMON-N

WRSNS

Figure 2-6

2 - 14

OUTSNS

Feed start

LEDSTB

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

First Tray

Turning the Hopping motor in the “a” direction drives the hopping roller of the first tray. Turning the Hopping motor in the “b” direction drives the Hopping roller of the front feeder. The both and hopping gears contain one-way bearing, so that turning each of these gears in reverse direction will not be transmitted to the corresponding roller.

One-way Clutch

Gear B

Hopping Roller

(Front Feeder)

Hopping Motor

Registration Roll

Hopping Roller

(First Tray)

2 - 15

One-way 

Clutch Gear A

(a) Hopping (1st tray)

1 Rotating the pulse motor in the direction a (CW direction) drives the hopping roller

of the first tray to advance the paper until the inlet sensor turns on. At the same time, the one-way clutch gear B also rotates. However, the hopping roller of the front feeder will not rotate due to the one-way bearing.

2 After turning on the inlet sensor, the paper advances further by a predetermined

length until it hits the registration roller. (The skew of the paper can thus be corrected.)

One-way Clutch Gear B

Inlet Sensor

Hopping Roller 

(Front feeder)

Registration Roll

Paper

Hopping Roller

(1st Tray)

2 - 16

(b) Hopping (front feeder)

1 Rotating the pulse motor in the direction b (CCW direction) drives the hopping roller

of the front feeder to advance the paper until the inlet sensor turns on. At the same time, the one-way clutch gear A also rotates. However, the hopping roller of the 1st tray will not rotate due to the one-way bearing.

A cam to push down the front feeder plate is attached on each of the ends of the hopping roller shaft. These cams push down the front feeder plate when the hopping operation is not performed so as to facilitate the setting of paper into the tray. A microswitch is provided under the front feeder plate to detect that the front feeder plate is at the lower position. When the front feeder plate is at the lower position, this microswitch causes the motor to stop.

Hopping Roller (Front Feeder)

Front Feeder 

Plate

Microswitch

Hopping Roller

(1st Tray)

Inlet Sensor

Paper

Registration Roller

One-way Clutch Gear A

2 After turning on the inlet sensor, the paper advances further by a predetermined

length until it hits the registration roller. (The skew of the paper can thus be corrected.)

2 - 17

OPC Drum

Paper

Registration

Roller

Hopping Roller

Paper Sensor

Transfer Roller

Pulse 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.

2 - 18

(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 - 19

(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 roll

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 - 20

(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 - 21

(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 400W 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 185 ~ 188°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 2.5 kg from the pressure spring at each side.

Paper

Separation Claw

Heater

Heater Roller

Thermistor

Back-up Roller

Pressure Spring

2 - 22

(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 - 23

2.4.4 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 (MSM6731BWAF) together as a pair.

The LED correcting head consists of the correction control LSI (MSM6730WAF), LED drivers

(MSM6731BWAF), and an LED array. The block diagram of the LED correcting head is shown below.

From

CPU

STRB1-N STRB2-N STRB3-N STRB4-N

LOADI

CLOCKI

DATAI0 DATAI1 DATAI2 DATAI3

MSM6730

WAF

 

EEPROM



Correction 

Values

LED Array

LED LED LED LED LED LED LED

MSM6731BWAF

LED Driver

MSM6731BWAF

LED Driver

MSM6731BWAF

LED Driver

MSM6731BWAF

Printing and correction data combined signal lin Correction data signal line

The existing LED head receives the printing data from the CPU directly at its LED drivers. With

the LED correcting head, a correction control LSI (MSM6730WAF) is connected between the CPU and LED drivers, so the printing data is input to the LED drivers through the correction control LSI. In order to maintain compatibility with the existing LED head, the printing operation of the LED correcting head is carried out through identical sequence.

The LED correcting head is a 600 dpi head, with the LED drivers located on both sides of the LED

array with a 300 dpi pitch spacing. The printing and correction data obtained from the CPU through four signal lines are sent to the LED array.

2 - 24

CLOCKI

LOADI

DATAI3~0

STRB1I-N

STRB2I-N

STRB3I-N

STRB4I-N

The printing operation timing chart is shown below.

Normal Mode Printing Timing Chart

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 LOADI signal level is low, the normal mode is enabled.

The printing operation is carried out in the following sequence. First, the printing data DATAI3 through DATAI0 are stored, sequentially shifted, in the shift registers of the LED drivers, by the printing data synchronous clock, CLOCKI. Then the printing data stored in shift registers are latched by the high level pulse of LOADI. The latched printing data turns the LEDs on by STRB1IN through STRB4I-N and actuates printing.

2 - 25

The mode setting timing chart during illumination correction is shown below.

Illumination Correction Mode Setting Timing Chart

100ns min

CLOCKI

LOADI

DATAI0

STRB1I-N

STRB2I-N

STRB3I-N

STRB4I-N

50ns 

min

D4 D3 D2 D1 D0

Mode setting Mode enabled

50ns 

min

200ns min 100ns min

Mode set

The mode setting is carried out in the following manner. LOADI is fixed at high level, and DATAI0

which comes up following this is 4-data latched with the timing of the fall of CLOCKI. The illumination correction mode is selected based on the latched 4-data combination. Then the mode becomes valid at the fifth fall of CLOCKI.

The period during which the illumination correction mode is valid is from the fall of the fifth CLOCKI

and while the level of LOADI is high. When the level of LOADI becomes low, the illumination correction mode is terminated, and the head returns to the normal mode, which is mode with which the printing is normally carried out.

2 - 26

The LED driver (MSM6731BWAF) 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 (MSM6731BWAF) used in an LED head is shown below.

LED Correction Data

msb b3

1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1

Corretion Data

b2

0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0

b1

Correction 

Step

lsb b0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0

0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1

 +16% +14% +12% +10%

+8% +6% +4% +2%

0%

-2%

-4%

-6%

-8%

-10%

-12%

-14%

Correction

Mode

 ↑ ↑



Correction by 



increasing 



illumination

↑ ↑ ↑



No correction

↓ ↓

Correction by 



decreasing 



illumination

 ↓ ↓

2 - 27

2.5 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 - 28

2.6 Cover Open

When the stacker cover is opened, the cover open microswitch on the power/sensor board is turned off to cut the supply of +30V to the high voltage power supply circuit. As a result, all highvoltage 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 control board performs the cover open processing.

2 - 29

2.7 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 - 30

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.

t1 > 3.398/4

3.398 SEC.

t1 ≤ 3.398/4

3.398 SEC.

• When there is no change with the toner sensor for 2 cycles (3.398 sec. x 2) or more, then the Toner Sensor Alarm is activated.

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

2 - 31

2.8 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.

2.9 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

2.10 PostScript Board (BOARD-PSBA) (Option)

The PostScript board consists of program/font ROM's, an EEPROM, and a LOCALTALK interface

control circuit.

(1) Program/font ROM's

The program/font ROM's store the PostScript Level II program and its fonts. MASK 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) LOCALTALK interface control circuit

Apple Talk protocol data is received from the host system via LOCALTALK interface. The LOCALTALK interface control circuit consists of a CPU, a program ROM, a SRAM, and a driver/receiver IC.

2 - 32

3. PARTS REPLACEMENT

The section explains the procedures for replacement of parts, assemplies, 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.

Q' ty Place of use RemarksService Tools

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

Disconnector for  Jack-in connector P/N 4PP4076-5395P1

2~2.5 mm screws

3~5 mm screws

Cleans LED head

Disconnect

Jack-in connector

3 - 2

3.2 Parts Layout

Face-up stacker assy

Transfer roller

Paper Cassette assy

Operator panel 

assy

Cover frame

I /F cover assy

BOARD-PSBA

(option)

Side cover (L)

assy

Rear cover

Contact

assy

Manual feed

hopper assy

Base unit

Main Control Board

(BOARD-COM)

Side  cover (R)

Figure 3-1

3 - 3

Front feeder unit

Fusing unit

Toner cartridge

Main motor

I/D unit

Registration motor

Hopping roller assy

LED head

Stacker cover

Eject roller assy

Main chassis

DC fan motor

Figure 3-2

3 - 4

Paper supply guide C

Earth plate

Hopping motor

Earth plate

Paper supply guide B

FF roller

Paper supply 

guide A

Figure 3-3

3 - 5

Insulator

Relay/Drive board

(AOLC-PCB)

Power/Sensor board

AOLS-PCB

Guide rail (L) assy

Guide rail

(R) assy

Figure 3-4

3 - 6

3.3 How to Change Parts

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

(3.3.13)

(3.3.14)

(3.3.15)

(3.3.16)(3.3.18)

Separator F

Front feeder roller assy

Hopping motor

Front feeder paper end sensor



Registration roller

(3.3.19)

(3.3.20)

(3.3.21)

Drum motor

Idle gear

Fusing assy

(3.3.22)

(3.3.23)

(3.3.24)

(3.3.25)

Backup roller

EP lock shaft

Hopping roller assy

Outlet sensor lever

(3.3.30)

(3.3.31)

Paper end lever

Guide rail (L) assy

(3.3.26)

(3.3.27)

(3.3.28)

(3.3.29)

Toner sensor lever

Paper sensor lever

Insensor lever

Spring-Insensor

Insulator

(3.3.32)

Guide rail (R) assy

(3.3.2)

(3.3.3)

Contact assy

DC fan motor



(3.3.1)

(3.3.4)

(3.3.8)

(3.3.9)

(3.3.10)

(3.3.11)

Stacker full sensor

Cable cover

Eject roller

(3.3.6)

(3.3.7) Damper

Earth Plate BK (R)

Stacker cover assy

(3.3.5)

(3.3.33)

(3.3.34)

(3.3.12)

Paper supply guide D

(3.3.35)



(3.3.36)



(3.3.17)



Main chassis unit

Rear cover

Printer Unit

Manual feed hopper assy

Side cover (R)



Cover frame

LED head

Separator assy

Transfer roller

3 - 7

3.3.1 Rear cover, side cover (L) Assy, face-up stacker Assy, and I/F cover Assy. (1) Turn the AC power switch off. Unplug the AC power cord from the outlet.

(2) Remove the interface cable 1. Remove drum/toner Assy 2A and store in black plastic bag

shipped w/printer.

(3) Open the face-up stacker Assy 8. Disconnect the engagement at the left and right

protrusions 8A . Remove the face-up stacker Assy 8. (Flex the Assy 8 in the middle to disengage 8A from the Rear cover 0.)

(4) Open the stacker cover 2 and the manual feed hopper Assy3. Remove three screws 4.

Remove the side cover (L) Assy 5. (5) Remove two screws 6. Remove the I/F cover Assy 7. (6) Remove two screws 9 and four claws A. (Use a small flat blade screw driver to "pop" claws.)

Remove the rear cover =.

Claw

3 - 8

3.3.2 Contact Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the side cover (L) Assy (see 3.3.1 (1) to (4)). (3) Remove two screws 1. Remove the contact plate (cover) 2 and the contact Assy 3. Pull

bottom of Assy 3 out first, then the top of Assy. Remove fan connector cables from location

Caution:

Be careful not to deform the electrodes of the contact Assy when removing the contact Assy.

3 - 9

3.3.3 DC fan motor (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the side cover (L) Assy (see 3.3.1 (1) to (4)). (3) Unplug the connector of the DC fan motor 1 and remove the DC fan motor 1.

3 - 10

3.3.4 Manual feed hopper Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Open manual feed hopper Assy 1. Disengage the lower portion of this Assy. (3) Hold manual feed hopper Assy 1 vertically and remove the left and right levers 2 with a

downward motion.

3 - 11

3.3.5 Side cover (R) (operator panel Assy) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove interface cable 1. (3) Open stacker cover 2. Remove two screws 3. Remove I/F cover Assy 4. (4) Remove two screws 5 and flexible cable 6 (use care to not damage flexible cable).

Remove operator panel Assy 7.

(5) Open manual feed hopper Assy 8. Remove three screws 9 and then remove side cover

(R) =.

3 - 12

3.3.6 Earth plate BK (R) (BOARD-PSBA, BOARD-COM) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove side cover (R) (see 3.3.5). (3) When PSBA-PCB is mounted, remove a screw 1. Remove BOARD-PSBA 2. (4) Remove five screws 3 and seven connectors 4. Remove BOARD-COM 5. (5) Remove two screws 6. Remove cover frame 7. (6) Remove four screws 8. Remove side plate (R) 9, by pulling up and out on top part of plate. (7) Remove the claws and then remove Earth plate BK (R) 0.

BOARD-PSBA



3 - 13

3.3.7 Stacker cover Assy, damper arm, and washer (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the rear cover (see 3.3.1). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the side plate (R) (see 3.3.6 (1) to (6)). (5) Disconnect the engagement of backup release lever 1 with the protrusion on the light side

surface on the right side of the stacker cover.

(6) Remove screw 2 and washer 3. Remove two claws. Remove stacker cover Assy 4 (at

this time, the damper arm 5 is also removed).

3 - 14

3.3.8 Damper (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the damper arm (see 3.3.7). (3) Remove two screws 1 and then remove two dampers 2.

This hole is elongated.

When replacing damper be sure  elongated hole is to rear of printer.

This hole is round.

3 - 15

3.3.9 Stacker full sensor Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the stacker cover Assy (see 3.3.7). (3) Remove four screw 1. Remove stacker mount 2 by releasing the tabs at position 2A . (4) Remove stacker full sensor Assy 3 by releasing spreading the plastic tabs on each side of

sensor Assy 3 and lifting switch from cover.

3 - 16

3.3.10 Cable cover (cable guides A and B) (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the stacker cover Assy (see 3.3.7). (3) Remove two screws 1 release tabs at position 1A . Remove cable cover 2, cable guide

A 3.



Note:

Use care when replacing cable cover. Do not pinch, crimp, or cut cables or protective sheet.

3 - 17

3.3.11 Eject roller Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the rear cover (se 3.3.1). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the side plate (R) (see 3.3.6 (1) to (6)). (5) Remove the stacker cover Assy (see 3.3.7). (6) Release the latch on the right side of eject roller Assy 1. Lift up and remove the eject roller

Assy.

3 - 18

3.3.12 Paper supply guide D (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the side cover (R) (see 3.3.5). (3) Remove five screws 1. Lift up and remove front feeder roller Assy 2. (4) Lift up and remove paper supply guide D 3. (At this time, two bias rollers 4 are also

removed. Be careful not to lose them.)

(5) Remove bias spring 5 from the paper supply guide D 3.

3 - 19

3.3.13 Separator F (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the manual feed hopper Assy (see 3.3.4). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the front feeder Assy (see 3.3.12 steps (1) to (3)). Make a diagram of wire locations

and routing.

(5) Remove two screws 1 and then remove the inner cover 2. At this time, the cover lock lever

3 and the torsion spring 4 are also removed note position of torsion spring. (6) Remove two screws 5 and then remove square-shaped connector 6. (7) Using a dedicated tool, remove the connector of switch Assy 7 from square-shaped

connector 6. (8) Turn idle gear 8 in the direction of arrow A until front feeder plate 9 is elevated. (9) Remove front feeder gear = and then remove two springs (F) A. Be careful not to lose the

springs. (10) Remove four screws B and then remove paper supply guide A C. (At this time, front feeder

earth plate D G H are also removed.) (11) Remove front feeder plate 9 by releasing the engagement at two parts 9A .

Switch Assy 7 may now be removed. (12) Pull up separator E toward you and then release two mounting posts at 15A to remove the

separator. (At this time, two springs F are also removed simultaneously. Be careful not to

lose the springs.) (13) Release two clutches on paper supply guide A C and pull out switch Assy 7 upward.

Switch Assy 7 should be moved more towards the center of the paper path.

During Re-assembly use great care: do not pinch, crimp, or cut wires to switch Assy 7.

3 - 20



15A

3 - 21

3.3.14 Front feeder roller Assy (1) Turn the AC power supply switch off. Unplug the AC power cord from the outlet. (2) Remove the manual feed hopper Assy (see 3.3.4). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the front feeder roller Assy (see 3.3.12 (1) to (3). (5) Remove the paper supply guide A (see 3.3.13 (1) to (10)). (6) Remove idle gear 1 and then remove the right side front feeder cam 2, release lever (R)

3, and spring 4. (At this time, knock pin 5 and bearing F 6 are also removed. Be careful

not to lose them.) Do not mix these parts with those from the left side of Assy. (7) Pull out the front feeder shaft 7 toward the left and then remove front feeder roller Assy 8. (8) Remove knock pin 9 and then remove front feeder cam = on the left (L) side, release lever

(L) A, and spring B. (At this time, the bearing F C on the left (L) side is also removed.) Do

not mix these parts with those from the right side of Assy.

Note 1:

2: 3:

Hopping roller orientation when removed from shaft. Be sure sensor arm swings freely after re-assembly. Be sure that during re-assembly both feeder cams (2 and =) are facing the same direction.

3 - 22

3.3.15 Hopping motor (1) Turn the AC power switch off. Unplug the AC power cable from the outlet. (2) Remove the manual feed hopper Assy (see 3.3.4). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the front feeder Assy (see 3.3.12.(1) to (3)). (5) Remove the inner cover and square-shaped connector (see 3.3.13.(5) and (6)). (6) Using a dedicated tool, remove the connector of hopping motor 1 from the square-shaped

connector. (7) Remove the paper supply guide A (see 3.3.13. (7) to (10)). (8) Remove the lever (R) (see 3.3.10. (6)). (9) Remove two screws 2 and then remove side plate (R) Assy 3. (10)Remove two screws 4 and then remove hopping motor 1.

3 - 23

3.3.16 Front feeder paper end sensor (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the manual feed hopper Assy (see 3.3.4). (3) Remove the side cover (R) (see 3.3.5). (4) Remove the front feeder roller Assy (see 3.3.12. (1) to (3)). (5) Remove the side plate (R) Assy (see 3.3.15. (1) to (9)). (6) Using a dedicated tool, remove the connector of front feeder paper end sensor 1 from the

square-shaped connector. (7) Remove two screws 2 and then remove paper supply guide C 3. (8) Remove paper supply guide B 4. (9) Remove four claws and then remove front feeder paper end sensor 1. (10) Remove two screws 5 and then remove square-shaped connector 6 from paper supply

guide C 3. (11) Using a dedicated tool, remove the connector cord 7 from the square-shaped connector.

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3.3.17 Main chassis unit (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the rear cover (see 3.3.1). (3) Remove the contact Assy (see 3.3.2). (4) Remove the side cover (R) (see 3.3.5). (5) Remove the side plate (R) (see 3.3.6 (1) to (6)). (6) Remove the stacker cover Assy (see 3.3.7). (7) Remove the front feeder roller Assy (see 3.3.12, (1) to (3)).

At this time, it is not required to remove the manual feed hopper Assy. (8) Remove the earth plate (HP). (9) Lift gear (TR) 1 to unlock it. Remove gear (TR) 1 and transfer roller 2. (At this time, two

bearings (TR) 3 and two transfer springs 4 are also removed.)

Do not lose bearings or springs. (10)Remove connector cover 5 in direction of arrow and then remove four connectors 6 and

7. (11)Remove the DC Fan motor. (12)Remove eight screws = and then remove main chassis unit A.

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3.3.18 Registration roller (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the front feeder roller Assy (see 3.3.12. (1) to (3)). (3) Remove four screws 1. Lift and remove the registration roller Assy 2, left side first then right

side. (4) Release the latch and remove registration roller gear 3 and pressure roller gear 4. (5) Remove left and right side registration roller bearing Assys 5 and then remove resist roller

6 and pressure roller 7.

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3.3.19 Drum motor (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove the registration roller Assy (see 3.3.18 (1) to (3)). (4) Remove fuser Assy. (5) Release the latch of fuser pressure roller release lever 1 and pull out it toward the right. (At

this time, idle gear H 2 is also removed.)

(6) Remove spring 3 and then remove pressure release lever 4. Be careful, do not lose or

damage spring. (7) Remove EP lock spring 5 and then remove ED lock lever 6. (8) Release two latches and remove motor Assy 7. (9) Remove two screws 8 and then remove drum motor 9 and heat sink. (10) Remove two screws = and then remove registration motor A.

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3.3.20 Idle gear (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove the motor Assy (see 3.3.19 (1) to (8)). (4) Remove three screws 1 and then remove motor bracket B 2. (5) Remove idler gear E 3, idle gear D 4, idle gear B 5, idle gear C 6, idle gear A 7, and two

resist idle gears 8.

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3.3.21 Fusing Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the side cover (L) Assy (see 3.3.1 (1) to (3)). (3) Unplug connector 1. (4) Remove four screws 2 and then remove fusing Assy 3.

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3.3.22 Fuser pressure roller (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove the fusing Assy (see 3.3.21). (4) Remove the fuser pressure roller release lever (see 3.3.19 (5)). (5) Remove two screws 2 and release three locks on the fusing guide. Remove the fusing guide

1 by pushing it upward from the lower side.

(6) Release the engagement with earth plate L (BK) 3. Lift and remove backup roller 4. (At

this time, two backup roller bearings 5 and two bias springs 6 are also removed.)

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3.3.23 EP lock shaft (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove screw 1. Turn EP lock level (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.

Spring located here.

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3.3.24 Hopping roller Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Release the latch. Remove hopping roller gear 1 and bearing P 2. Then, remove idle gear

HF 3.

(4) Remove the left side of hopping roller shaft 4 from the groove. Pull out hopping roller shaft

4 and hopping roller Assy 5 toward the left.. (5) Release the latch and remove bearing L 6. (6) Release the latch and remove hopping roller Assy 5. (At this time, knock pin 7 is also

removed. Be careful not to lose the knock pin.)

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3.3.25 Outlet sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Press the clamp part of outlet sensor lever 1. Remove the outlet sensor lever 1 by pushing

it upward from the lower side.

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3.3.26 Toner sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (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.

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3.2.27 Paper sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Squeeze the clamp part of the paper sensor lever 1. Remove the paper sensor lever 1 by

pushing it upward from the lower side.

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3.3.28 Inlet sensor lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (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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3.3.29 Insulator (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove two screws 1 and then remove inlet holder 2. At this time, remove inlet 3 from

inlet holder 2.

(4) Remove eight screws 4, connector 5, and two screws 6. Remove Power/sensor PCB 7

together with AOLC-PCB 8. (5) Unplug connector 9 and remove Power/sensor PCB 7. (6) Remove insulator =.

Caution:

Be careful not to deform the paper end lever A.

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3.3.30 Paper end lever (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Release the lock and remove paper end lever 1.

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3.3.31 Guide rail (L) Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove the insulator (see 3.3.29). (4) Remove screw 1 and then remove base plate 2. (5) Remove two screws 3 and then remove guide rail (L) Assy 4. (6) Remove cassette lock spring 5 and then remove bias link 6 and pull block 7.

(Pay attention the direction of hook of cassette lock spring 5.) (7) Remove spring 8 and then remove cassette stopper 9. (8) Remove screw 0 from bias link 6 and then remove link support A.

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3.3.32 Guide rail (R) Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove the main chassis unit (see 3.3.17). (3) Remove the insulator (see 3.3.29). (4) Remove screw 1 and then remove base plate 2. (5) Remove two screws 3 and then remove guide rail (R) Assy 4. (6) Remove cassette lock spring 5 and then remove bias link 6 and pull block 7 (At this time,

earth plate 8 is also removed.)

(Pay attention the direction of hook of cassette lock spring 5.) (7) Remove spring 9 and then remove cassette stopper =. (8) Remove screw A and then remove detector spring B. (9) Remove screw C and then remove AOLS-PCB D. (10) Remove screws E from bias link 6 and then remove link support F. (11) Remove two screws G and then remove square cord from square-shaped connector H. (12) Using a dedicated tool, remove connector cord I from square-shaped connector H.

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3.3.33 Cover Frame (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Remove interface cable 1. (3) Open stacker cover 2. Remove two screws 3 and then remove Cover Frame 4.

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3.3.34 LED head (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Open stacker cover 1. (3) Remove PC connectors 2 and two LED cables 3 from LED head 4. (4) Push the hook on the left side of stacker cover 1 in the direction of arrow and remove LED

head 4. (Take care not to lose head springs.)

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

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3.3.35 Separator Assy (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Pull out the paper cassette Assy 1 from the printer. (3) Release two locks and remove separator Assy 2. (At this time, leaf spring 3 and coil spring

4 are also removed. Be careful not to lose these springs.)

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3.3.36 Transfer roller (1) Turn the AC power switch off. Unplug the AC power cord from the outlet. (2) Open stacker cover 1. (3) Lift the left side of the gear TR 2 and release the lock. Remove gear TR 2 and transfer roller

3. (At this time, two bearings (TR) 4 and two transfer roller springs 5 are also removed.)

(4) Remove diselectrification bar 6 and diselectrification film 7 from the chassis unit.

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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 seven functions as follows.

• Menu reset • Hex dump

• Drum counter reset • Operator panel menu disable

• X adjust • Y adjust

• Setting

• 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

• EEPROM reset • Rolling ASCII continus prinitng

• HSP ERROR Recovery • HSP ERROR count display

• HSP ERROR count reset • SIDM enable/disable

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• 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 15 functions as follows.

• Head drive time setting

• Setting of Head drive timing compensation while OST is on.

• Compensated head type setting

• 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 envelope feeder paper feed length

• Selection of envelope feeder download table

• Fuser count indication

• Fuser count reset

• Engine reset

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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) 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).

(5) 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.

(6) 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.

(7) SETTING

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

–2

Rough/thick paper, low temperature/humidity and/or blockly faded print

–1

appeared. Normal media/environmental conditions.

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

pattern.

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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.

OP MENU ENABLE *

Press the Menu key.

X-ADJUST 0 mm*

Press the Menu key.

Y-ADJUST 0 mm*

Press the Menu key.

SETTING 0 *

Press the Menu key.

Press the ON LINE key.

INITIALIZING

Press the Enter key.

Press the or key.

MENU RESET'NG

ON-LINE HEX DUMP

DRUM CNT RESET'NG

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

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

+2 +1 0 *

-1

-2

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)

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*** 

ON-LINE***

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) 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.

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(5) HSP ERROR recovery

• Select HSP ERROR recovery function either recover or stop.

(6) HSP ERROR count

• Display total HSP ERROR count.

(7) HSP ERROR count reset

• Reset the HSP ERROR counter.

(8) SIDM enable/disable

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

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OKI PAGE 16n Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

CONTENTS

1. CONFIGURATION

2. OPERATION DESCRIPTION

3. PARTS REPLACEMENT

4. ADJUSTMENT