OKI 8p, 8w Service manual

OKIPAGE

8p /8

LED Page Printer

Maintenance Manual

ODA/OEL/INT

Rev. 2 1997,11,12

All specifications are subject to change without notice.

XXXXXXXXTH

PREFACE

This Maintenance Manual describes the field maintenance methods for LED Page Printers. This manual is written for use by service persons. Please note that you should refer to the Printer

Handbook for the handling and operating methods of the equipment.

CONTENTS

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

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

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

1.3 Option(OKIPAGE 8p Only) ................................................................ 1 - 3

1.4 Specification ...................................................................................... 1 - 4

1.5 Safety Standards ............................................................................... 1 - 6

1.5.1 Certification Label.................................................................................... 1 - 6

1.5.2 Warning Label ......................................................................................... 1 - 6

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

2.1 Main Control Board............................................................................ 2 - 3

2.2 Power Supply Unit ............................................................................. 2 - 5

2.3 High-Voltage Power Supply Board .................................................... 2 - 5

2.4 Electro-Photographic Processor........................................................ 2 - 7

2.5 Electro-Photographic Process ........................................................... 2 - 11

2.5.1 Explanation of Each Process Operation.................................................. 2 - 13

2.6 Paper Jam Detection ......................................................................... 2 - 19

2.7 Toner Low Detection.......................................................................... 2 - 21

2.8 Cover Open ....................................................................................... 2 - 22

2.9 Detecting ID existence....................................................................... 2 - 23

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

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

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

3.3 Replacing Parts ................................................................................. 3 - 7

3.3.1 Hopper Plate ........................................................................................... 3 - 7

3.3.2 LED Head and Head Spring.................................................................... 3 - 8

3.3.3 Transfer Roller......................................................................................... 3 - 9

3.3.4 Upper Cover Assy ................................................................................... 3 - 10

3.3.5 High-Voltage Power Supply Board (P2H/ P6L) ....................................... 3 - 11

3.3.6 Top Cover Assy and Flat Cable Assy...................................................... 3 - 12

3.3.7 Paper Holder ...........................................................................................3 - 13

3.3.8 Side Plate M and Idle Gear ..................................................................... 3 - 14

3.3.9 Heat Assy ................................................................................................ 3 - 15

3.3.10 Drive Shaft E (Eject) and Eject Roller ..................................................... 3 - 18

3.3.11 Pressure Roller B (Back Up Roller)......................................................... 3 - 19

3.3.12 Separator Guide ...................................................................................... 3 - 20

3.3.13 Pulse Motor (Main) .................................................................................. 3 - 23

3.3.14 Hopping Shaft Assy ................................................................................. 3 - 24

3.3.15 Resist Roller ............................................................................................ 3 - 25

3.3.16 Paper Sensor E, Paper Sensor Exit and Toner Sensor Assy ................. 3 - 26

3.3.17 Base Plate ............................................................................................... 3 - 27

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

4.1 Adjustment Types and Functions ...................................................... 4 - 1

4.1.1 Printer Driver ........................................................................................... 4 - 1

4.1.2 Engine Maintenance Utility ...................................................................... 4 - 2

4.2 Adjustment When Replacing a Part................................................... 4 - 2

4.2.1 Setting LED Head Drive Time ................................................................. 4 - 2

4.2.2 Uploading and Downloading EEPROM Data .......................................... 4 - 3

5. PERIODICAL MAINTENANCE ................................................................. 5 - 1

5.1 Periodical Replacement Parts ........................................................... 5 - 1

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

5.2.1 Cleaning the LED Lens Array .................................................................. 5 - 1

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

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

6.2 Check Points Before Correcting Image Problems ............................. 6 - 1

6.3 Notes When Correcting Image Problems .......................................... 6 - 1

6.4 Preparation Before Troubleshooting.................................................. 6 - 1

6.5 Troubleshooting................................................................................. 6 - 3

6.5.1 Status Monitor Message List ................................................................... 6 - 3

6.5.2 Status Message Troubleshooting ............................................................ 6 - 7

6.5.3 Image Troubleshooting ............................................................................ 6 - 13

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

7.1 (a)Interconnect Signal Diagram (OKIPAGE 8p) ................................ 7 - 1

7.1 (b)Interconnect Signal Diagram (OKIPAGE 8w)................................ 7 - 2

7.2.1 Main Control board (NMA PCB)(OKIPAGE 8p) ...................................... 7 - 3

7.2.2 Main Control board (NMA PCB)(OKIPAGE 8w) ...................................... 7 - 4

7.2.3 High-Voltage Power Sapply Board .......................................................... 7 - 5

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

APPENDIX A LOCAL PRINTING.............................................................. A - 1

APPENDIX B PARALLEL INTERFACE ................................................... B - 1

APPENDIX C MACINTOSH INTERFACE................................................. C - 1

APPENDIX D DETAIL OF EACH FUNCTION .......................................... D - 1

1. CONFIGURATION

1.1 System Configuration

The OKIPAGE 8p/8w consists of a control block, a power supply unit, and an engine block. (See Figure 1-1.)

ENGINE UNIT

Paper Feed Mechanism

Hopper

Plate

Electro-photographic

Processor

Main High-Voltage

Power Supply Board

Sub High-Voltage

PowerSupply Board

Power Supply Unit

Main Control Board

4MB Memory

Expansion Board

(OKIPAGE 8p Only)

Figure 1-1

1 - 1

1.2 Printer Configuration

The printer unit consists of the following five hardware components:

• Electro-Photographic Processor

• Paper Feeder

• Main Control Board

• High-Voltage Power Supply Board (two Boards)

• Power Supply Unit Figure 1-2 is the configuration of the printer unit.

Upper Cover Assy

EP Unit (Type 6)

Top Cover Assy

High-voltage Power Supply Board (P2H)

Heat Assy

Main Control Board

High-voltage Power Supply Board (P6L)

1 - 2

1.3 Option(OKIPAGE 8p Only)

(1) 4MB N4A-PCB Option Memory Board

1 - 3

1.4 Specification

(1) Type Desktop (2) Outside dimensions Height 5.9” (150 mm)

(excludes protruding Width 12.2” (310 mm)

portion) Depth 7.5” (191 mm) (3) Weight 3.8 kg (4) Development method Dry non-magnetic development system

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>

14" (355.6 mm) (Max.) x 8.5" (215.9 mm)

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

ency)

(6) Printing speed First print: 23 seconds (A4) (after warm-up)

Continuous print: 4 sheets/minute (A4) Warm-up time: 40 seconds (120 VAC for ODA, 230

VAC for OEL/INT) (at room tempera-

ture 77 ˚F (25 ˚C)) (7) Paper feeding method Automatic paper feed or manual paper feed (8) Paper delivery method Face down (9) Resolution 600 dpi x 600 dpi (true) (10) Power input 230 VAC ±10% (for OEL/INT)

120 VAC +6%, -15% (for ODA)

(11) Power consumption Peak: Approx. 450W

Typical operation: Approx. 100W Idle: Approx. 30W Power save mode: Approx. 5W

1 - 4

(12)Temperature and humidity

During operation In storage

Caution:

Temperature and humidity in storage are measured with the OKIPAGE 8p/8w being packed; they are valid for one year.

Temperature 10 to 32 ˚C –10 to +43 ˚C

20 to 80% RH (relative humidity) 10 to 90% RH (relative humidity)

No condensation is permissible.

Humidity

(13)Noise During operation: 48 dB (A) or less

Standby: 38 dB (A) or less

(14)Consumables Toner cartridge kit 1,500 (5% duty)

Image drum cartridge 10,000 (at continuouts printing)

........

45g cartridge kit

1 - 5

1.5 Safety Standards

1.5.1 Certification Label The safety certification label is affixed to the following location of the OKIPAGE 4w Plus:

1.5.2 Warning Label Warning labels are affixed to the locations that may cause bodily injury. During maintenance, do work with enough care while following instructions on these warning

labels.

For OEL

1 - 6

For OEL, OKI-INT

For China, TAIWANFor Korea

2. OPERATION DESCRIPTION

The OKIPAGE 8p/8w consists of a main control board, a high-voltage power supply board, a power supply unit, and an electro-photographic processor. The OKIPAGE 8p/8w receives print data from a higher-level interface and sequentially stores it in memory. The OKIPAGE 8p/8w decodes and edits the received data while storing print data from the interface in memory. It sequentially transfers the edited data to the LED head for each dot line. The electro-photographic processor then prints the data on sheets of paper.

The display of the higher-level host is used for device operation and status display. Figure 2-1 is the block diagram of the OKIPAGE 8p/8w.

2 - 1

PLUNGER LED HEAD

Main Motor

PJ HEAD1 HEAD2

5V 0V

MOTOR

Motor Driver

MTD2005F

EEPROM

1kb

CPU

(NKK 3 or 5)

Serial i/f

Data Bus

(x 16)

Address Bus

CENT

LS07

+26V+5V 0V 0VP

POWER HIVOL HIVOL2

HC244

LSI

LC26023A

RST

OSC

7MHz

OSC

10MHz

M-ROM

4M x 16

Mask ROM 8MB(PCL6)

OPTION

DRAM

1M x 16

Power Supply Unit

High Voltage Power Unit

(Main)

High Voltage Power Unit

(Sub)

Parallel

i/f

Red

Amber

DRAM

1M x 16

RAM BOARD

(N4A PCB)

DRAM 4MB

OPTION BOARD(8p Only)

Figure 2-1 Block Diagram (OKIPAGE 8p/8w)

2 - 2

2.1 Main Control Board

The main control board consists of a one-chip CPU, a program ROM, a DRAM, an EEPROM, a host interface circuit, and a mechanism driving circuit. The mechanism driving circuit consists of a LED head, a main motor, and an electromagnetic clutch.

(1) One-chip CPU

• OKIPAGE 8p

The one-chip CPU is a custom CPU (32-bit internal bus, 16-bit external bus, 28-MHz clock). This CPU has the functions listed in the table below.

Built-in Device Function DRAM controller DMA controller

Parallel interface controller Video output port

LED STB output port Timer

I/O port

Controls DRAM. Transfers image data from Parallel I/F to DRAM, from DRAM to a video output port and

between CPU and DRAM. Controls the parallel interface. Controls LED head.

Generates various control timings for monitoring paper feeding and a paper size. Inputs and outputs the sensor signals and motor signals, etc.

Also performs I/O for EEPROM.

• OKIPAGE 8w The one-chip CPU is a custom CPU (8-bit internal bus, 8-bit external bus, 16-MHz clock)

incorporating mask ROM and CPU peripheral devices. This CPU has the functions listed in the table below.

Built-in Device Function DRAM controller DMA controller

Controls DRAM. Transfers image data from Parallel I/F to DRAM, from DRAM to a video output port and

between CPU and DRAM. Parallel interface controller Video output port

LED STB output port Timer

I/O port

A/D converter

Controls the parallel interface.

Controls LED head.

Generates various control timings for monitoring paper feeding and a paper size.

Inputs and outputs the sensor signals and motor signals, etc.

Also performs I/O for EEPROM.

Inputs the feedback signals from a high-voltage generation circuit and thermistor signal.

2 - 3

(2) Program ROM

Program ROM contains a program for the equipment. EPROM is used as program ROM. When mask ROM in the one-chip CPU explained in (1) above is valid, the EPROM is not mounted. (For details on short wiring setting, see Section 7.2.)

(3) DRAM

DRAM is used as resident memory.

(4) EEPROM

EEPROM holds the following data:

• Menu data

• Counter value

• Adjustment value

(5) Parallel interface

The parallel interface receives parallel data from the host; it conforms to the IEEE1284 specification.

2 - 4

2.2 Power Supply Unit

The power supply unit supplies +5 V and +26 V to the main control board according to 230 VAC / 120 VAC.

Output voltage Application

+5 V

+26V

Used to generate a logic circuit and a high voltage. Used to drive the motor and electromagnetic clutch.

The power supply unit also contains a heater drive circuit.

2.3 High-Voltage Power Supply Board

(1) High-Voltage power supply circuit

The high-voltage power supply circuit generates the following voltages required for the electro-photographic processor from +5 V according to the control sequence from the main control board. When the cover is open, +5 V supply is automatically interrupted to stop highvoltage output.

Output Application

–1.3 KV

–265 V/+265 V

–520 V/ 0 V

+400 V/–1.3 KV

+500 V ~ +3.5 KV/–750 V

Voltage

Voltage to be applied to a charge roller. Voltage to be applied to a developing roller. Voltage to be applied to a sponge roller. Voltage to be applied to a cleaning roller. Voltage to be applied to a transfer roller.

Caution:

The TR voltage varies with medium and transfer roller impedance.

2 - 5

(2) Sensors

The high-voltage power supply board consists of the high-voltage power supply circuit that supplies power to the electro-photographic processor system and the photosensor that detects a paper feeding system and toners.

Figure 2-2 shows the sensor layout drawing.

Exit roller

Outlet sensor

Heat roller

Transfer roller

Paper sensor

Toner sensor assy

Manual feed sensor

Paper feeding direction

Feed roller

Hopping

roller

Figure 2-2

Sensor Function Sensing State

Manual feed sensor

Paper sensor

Outlet sensor

Toner sensor

Monitors whether paper was inserted into the manual feed sensor section.

Detects the leading part of the paper. Monitors paper feeding.

Monitors paper feeding and the paper size according to the paper sensor arrival and passing time.

Detects the low toner status.

ON: Paper exists. OFF: No paper exists.

ON (long): Toner low OFF (short): Toner High

2 - 6

2.4 Electro-Photographic Processor

The electro-photographic processor prints out the image data to be sent from the main control board on sheets of paper. Figure 2-3 shows the layout drawing of the electro-photographic processor.

(1) Image drum unit

The image drum unit makes a toner adhere to the formed electrostatic latent image with static electricity. This electrostatic latent image is formed by the lights irradiated from LED heads.

(2) Electromagnetic clutch

The electromagnetic clutch controls the rotation of the hopping roller according to signals from the control block.

2 - 7

Exit roller

Heat roller

(ø 19.910)

6.85

OFF

26.50

Outlet sensor

Cleaning roller

(ø 9.000)

Charge roller

(ø 9.000)

6.77

LED head

Drum roller

(ø 16.000)

Developing roller

(ø 14.000)

17.23

12.72

23.18

20.32

64.60

Single tray

Transfer roller

(ø 15.000)

Hopping roller

OFF

32.00

Tray printing

OFF

Manual feed sensor

Manual printing

Feed roller

Paper sensor

Figure 2-3 Layout Drawing of Electro-Photographic Processor

2 - 8

(3) Pulse motor (Main)

This pulse motor of 48 steps/rotation is two-phase excited by the signal from the main control board; it performs feeding control by switching normal rotation to reverse rotation or vice versa and turning on/off the electromagnetic clutch. The relationship between the main motor, electromagnetic clutch, resist gear, drum gear, hopping roller is shown in the table below and on the subsequent pages.

Main Motor Electromagnetic Clutch

Normal rotation

Reverse rotation

OFF

Hopping Roller

Non-rotation

Rotation

Non-rotation

Regist Gear Drum Gear Operation Non-rotation

Rotation Rotation

Rotation Rotation Rotation

(4) LED head

The shift and latch registers receive image data from the main control board for each dot line. 4,992 LEDs are driven to radiate the image drum.

(5) Heat Assy

The heat Assy consists of a heater, a heat roller, a thermistor, and a thermostat. The power supply unit supplies AC voltage to the heater according to the HEATON signal

from the main control board to heat the heat roller. The main control board monitors the heat roller temperature via the thermistor and keeps the temperature constant by turning on/off the heater AC voltage supply.

If the heat roller temperature rises abnormally, the thermostat of the heater voltage supply circuit functions to forcibly suspend the AC voltage supply.

Warm-up

Hopping

Prinitng

2 - 9

Exit roller

Heat roller

Transfer roller

Cleaning roller

CH roller

Drum roller

Developing roller

Outlet

sensor

Paper sensor

Hopping roller

TRAY printing

Feed roller

Manual

feed

sensor

Manual printing

Roller to be driven by reverse

rotation of pulse motor (Main)

Motor to be driven by normal

rotation of pulse motor (main)

Roller control by pulse motor (main)

Normal rotation of pulse motor (main): Drum roller, transfer roller, cleaning roller, CH roller, developing roller, heat roller, exit roller rotation

Reverse rotation of pulse motor (main): Drum roller, transfer roller, cleaning roller, CH roller, developing roller, heat roller, exit roller, feed roller,

hopping roller rotation

Hopping operation from the tray, however, is performed when the electromagnetic clutch is turned on.

Figure 2-4 Schematic Drawing of OKIPAGE8p/8w Paper Feeding

2 - 10

2.5 Electro-Photographic Process

(1) Electro-photographic process

The electro-photographic process is outlined below. 1 Charging

The surface of the OPC drum is charged negatively and uniformly by applying the DC voltage to the CH roller.

2 Exposure

Light emitted from the LED head irradiates the negatively charged surface of the OPC drum. The surface potential of the irradiated surface attenuates to form the electrostatic latent image corresponding to the image signal.

3 Development and residual toner recovery

The negatively charged toner is brought into contact with the OPC drum, adhering to the electrostatic latent image on the OPC drum by static electricity. This adhesion causes the electrostatic latent image to change to a visible image.

At the same time, the residual toner on the OPC drum is attracted to the developing rollerby static electricity.

4 Transfer

When paper is placed over the image drum surface, the positive charge which is opposite in polarity to that of the toner, is applied to the reverse side by the transfer roller. The toner is attracted by the positive charge and is transferred onto the paper. This results in the transfer of the toner image formed on the image drum onto the paper.

5 Cleaning

The cleaning roller temporarily attracts the residual toner on the transferred OPC drum with static electricity, then returns the toner to the OPC drum.

6 Fusing

The transferred unfused toner image is fused to a sheet of paper by applying heat and pressure to the image.

Figure 2-5 is a flow for the electro-photographic process.

2 - 11

Paper

holder

section

Manual feed

Control signal

LED head

Power

supply

Exposure

Toner

cartridge

roller

Developing

Paper

supply

Transfer

Manual feed

roller

Hopping

Feed roller

Paper sensor

Transfer roller

sensor

: OPC drum rotation direction

: Paper feeding path

Power

supply

roller

Charge

Paper delivery

Charging

Power

supply

Cleaning Development

roller

Cleaning

Paper feeding

Outlet sensor

roller

Paper eject

Fusing

Power

supply

roller

Back-up

Heat roller

Figure 2-5 Flow for Electro-Photographic Process

Paper ejection Fusing Cleaning Transfer Development Paper feed Paper hopping

2 - 12

2.5.1 Explanation of Each Process Operation (1) Hopping

As shown in the figure below, the clutch for hopping is turned on/off according to current ON/ OFF to a coil.

When the clutch is OFF

Coil

Hopping gear

Spring for resetting

Clutch plate

Magnetic substance plate

Hopping roller

When the clutch is ON

Hopping shaft

Hopping gear

Engagement section

Clutch plate

When the clutch is on, the hopping gear engages with the clutch plate to rotate the hopping roller.

When the clutch is off, the hopping gear is separated from the clutch plate by the spring for resetting, disabling the rotation of the hopping roller.

2 - 13

(2) Printing and warm-up

At warm-up

Regist gear

Hopping gear

Triple gear

Transfer gear

Idle gear

Planetary gear

Gear A

Pulse motor (main)

Rotate the pulse motor (main) in the a direction. The planetary gear rotates in the a’ direction, dislocating its position in the a” direction. This causes the planetary gear to be separated from gear A. The hopping gear will not rotate. The triple gear and transfer gear rotate via the idle gear to drive the EP unit.

At printing

Triple gear

Transfer gear

Regist gear

Idle gear

Planetary gear

Hopping gear

Gear A

Pulse motor (main)

The paper is further advanced in synchronization to the print data.

2 - 14

(3) Charging

Charging is performed by applying DC voltage to the charge roller that is in contact with the surface of the OPC drum.

High-

voltage

power supply

Charge roller

OPC drum

(4) Exposure

High-

voltage

power supply

LED head

Charge roller

LED head

OPC drum

2 - 15

Paper

Image drum

(5) Development

The electrostatic latent image on the surface of the OPC drum is changed to a visible toner image by applying a toner to it. Development is performed in the contact part between the OPC drum and developing roller.

1 The sponge roller negatively charges a toner and applies it to the developing roller.

Developing blade

Charge roller

Developing roller

OPC drum

Sponge roller

2 The toner applied to the developing roller is thin-coated by the developing blade. 3 A toner adheres to the exposure part of the OPC drum in the contact part between the

OPC drum and developing roller. This causes the electrostatic latent image to be changed to a visible image.

2 - 16

(6) Transfer

The transfer roller is composed of conductive sponge material. This roller is set so that the surface of the OPC drum and sheets of paper will adhere closely.

A sheet of paper is placed on the surface of the OPC drum and the positive charge opposite to the negative charge of a toner is applied from the reverse side by the transfer roller.

When a high negative voltage is applied from the power supply to the transfer roller, the positive charge induced on the surface of the transfer roller moves to the paper side at the contact part between the transfer roller and the sheet of paper. The positive charge on the lower side of the sheet of paper then causes the negatively charged toner adhering to the surface of the OPC drum to move to the upper side of the sheet. This enables transfer to the sheet of paper.

OPC drum

Transfer roller

Paper

High-voltage

power supply

2 - 17

(7) Fusing

The transferred unfused toner image is fused to a sheet of paper because heat and pressure are applied when it passes between the heat roller and back-up roller.

The Teflon-coated heat roller contains a 400 W heater (Halogen lamp) that heats the heat roller. The thermistor on the surface of the heat roller keeps the temperature of the heat roller constant. A thermostat is also installed for safety. If temperature rises abnormally, this thermostat opens to suspend voltage supply to the heater.

The back-up roller is pressurized to the heat roller by the pressure spring on each side.

Thermistor

Separation claw

Heater roller

Heater

Back-up roller

(8) Cleaning

Pressure Sprin

After transfer has terminated, the cleaning roller temporarily draws in the untransferred residual toner adhering to the OPC drum with static electricity and then returns it to the OPC drum.

OPC drum

Cleaning roller

High-voltage

power supply

Transfer roller

2 - 18

+ 96 hidden pages