Brother HL-1660e Series, HL-1660 Series User Manual

No part this publication may be reproduced in any form or by any means without permission in writing
from the publisher.

Trademarks:

• BR-Script, and DX-1600 are registered trademarks of Brother Industries, Ltd.

• Centronics is a registered trademark of Genicom Corporation.

• PostScrip is a registered trademark of Adobe Systems Incorporated.

• IBM Proprinter XL is a registered trademark of International Business Machines Corporation.

• EPSON FX-850 is a registered trademark of Seiko Epson Corporation.

• HP-GL and HP Laser Jet 5 are registered trademarks of Hewlett Packard Company.

This service manual contains basic information required for after-sales service of the laser printer (hereinafter
referred to as ”this machine” or ” the printer”). This information is vital to the service technician in maintaining
the high printing quality and performance of the printer.

This manual consists of the following chapters:
Chapter I : General

Features, specifications, etc.

Chapter II : Theory of Operation

Basic operation of the mechanical system and the electrical system, and their timing.

Chapter III : Electrical System

Theory of the electronics circuit

Chapter IV : Mechanical System

Requirements for a suitable location, disassembling and reassembling procedure of

mechanical system.

Chapter V : Maintenance and Servicing

Parts replacement schedule, list of tools, lubricants and cleaners.

Chapter VI : Troubleshooting

Reference values and adjustment, troubleshooting for image defects, troubleshooting

for malfunctions, etc.

Appendices : Engine Block Diagram, PCB Circuitry Diagrams, etc.

Information in this manual is subject to change due to improvement or re-design of the product. All relevant
information in such cases will be supplied in service information bulletins (Technical Information).

A thorough understanding of this printer, based on information in this service manual and service
information bulletins, is required for maintaining its quality performance and for fostering the practical ability
to find the cause of troubles.

PREFACE

i

CONTENTS

CHAPTER I GENERAL

1. FEA TURES..........................................................................................................................I-1

2 . SPECIFICATIONS ...............................................................................................................I-1

3 . SAFETY INFORMA TION .....................................................................................................I-6

3.1 Laser Safety (110 - 120V Model only) ........................................................................ I-6

3.2 CDRH Regulations (110 - 120V Model only) ...............................................................I-7

3.3 Additional Information ................................................................................................ I-7

4 . PAR TS OF THE PRINTER...................................................................................................I-8

4.1 External Views...........................................................................................................I-8

4.2 Cross Sectional View.................................................................................................I-9

5. STORAGE AND HANDLING OF EP-ED CARTRIDGES..................................................... I-10

5.1 Storage of Sealed EP-ED Cartridges .......................................................................I-10

5.2 Storage of Unsealed EP-ED Cartridges ...................................................................I-10

CHAPTER II THEORY OF OPERATION

1 . BASIC OPERATIONS........................................................................................................ II-1

1.1 Mechanical Configuration ......................................................................................... II -1

1.2 Main Drive ............................................................................................................... II -2

1.3 Basic Sequence of Operations ................................................................................ II-3

2 . LASER/SCANNER SYSTEM............................................................................................. II-4

3 . IMAGE FORMA TION SYSTEM ......................................................................................... II-5

3.1 Outline ..................................................................................................................... II-5

3.2 Printing Process ...................................................................................................... II-5

3.2.1 Electrostatic latent image formation stage................................................. II-6

3.2.2 Developing stage....................................................................................... II -8

3.2.3 Transfer stage............................................................................................ II-9

3.2.4 Fixing stage..............................................................................................II-10

3.2.5 Drum cleaning stage.................................................................................II-10

3.3 Operation ................................................................................................................II-11

4 . PAPER PICK-UP/FEED SYSTEM....................................................................................II-12

4.1 Outline ....................................................................................................................II-12

4.2 Cassette Feed ........................................................................................................ II-13

4.3 MP Tray Feed .........................................................................................................II-14

4.4 Paper Jam Detection ..............................................................................................II-15

ii

CHAPTER III ELECTRICAL SYSTEM

1 . MAIN PCB ........................................................................................................................ III-1

1.1 Outline.................................................................................................................... III -1

1.2 Video Controller Circuit ........................................................................................... III-2

1.3 Engine Controller Circuit ......................................................................................... III-7

2 . PAPER FEED DRIVE CIRCUIT ........................................................................................ III-9

3 . DISPLA Y CIRCUIT ..........................................................................................................III-11

3.1 Outline...................................................................................................................III -11

3.2 Operation ...............................................................................................................III -11

4 . LOW-VOL TAGE POWER SUPPL Y ASSY......................................................................... III-12

4.1 Outline...................................................................................................................III -12

4.2 Protection Functions..............................................................................................III-12

5 . HIGH-VOL T AGE POWER SUPPL Y ASSY .......................................................................III-14

5.1 Outline...................................................................................................................III-14

5.2 Operation of the Components of the High-V oltage Power Supply Assy ..................III-14

CHAPTER IV MECHANICAL SYSTEM

PRINTER DISASSEMBLING PROCEDURE

PRINTER BODY

1.1 Configuration........................................................................................................... IV-3

1.2 T oner Cartridge Lid.................................................................................................. IV -3

1.3 Side Cover L........................................................................................................... IV-3

1.4 Font Cover Assy..................................................................................................... IV-4

1.5 Upper Cover Assy, Rear Cover Assy ...................................................................... IV-4

1.5.1 Upper cover assy , rear cover assy ........................................................... IV-4

1.5.2 Changeover guide, jam remove cover....................................................... IV -5

1.6 Side Cover R .......................................................................................................... IV-5

1.7 DC Fan Motor ......................................................................................................... IV-6

1.8 Main PCB............................................................................................................... IV -6

1.9 Control Panel Unit ................................................................................................... IV-8

1.10 Scanner Unit........................................................................................................... IV -9

1.11 Cartridge Stopper Assy .......................................................................................... IV-9

1.12 Paper Feed Chassis Unit .......................................................................................IV-10

1.13 Separation Pad Assy .............................................................................................IV-1 1

1.14 MP PE Sub Actuator .............................................................................................IV-12

1.15 P Feed /Size-SW PCB Assy .................................................................................IV-12

1.16 Side-Switch Spring ................................................................................................IV-12

1.17 Regist Sensor Actuator..........................................................................................IV-13

1.18 MP Paper Detection Actuator.................................................................................IV-13

1.19 PE Sensor Actuator MP ........................................................................................IV-13

1.20 Tray Sensor Holder ................................................................................................IV-14

1.21 Roller Holder ..........................................................................................................IV-14

1.22 Paper Pick-up Roller Assy , Bearing........................................................................IV-15

1.23 Paper Pick-up Solenoid..........................................................................................IV-16

1.24 Paper Feed Motor Assy .........................................................................................IV-16

1.25 MP Tray Cover .......................................................................................................IV-17

1.26 MP Tray Assy ........................................................................................................IV-17

1.27 Paper Path Separation Plate, Paper Path Separation Film ......................................IV-18

1.28 Latch .....................................................................................................................IV-19

1.29 Fixing Unit (for both 120V and 230V , the only difference is the halogen heater) ....IV-19

1.30 Transfer Unit ..........................................................................................................IV-22

iii

1.31 DC Gear Holder Assy ............................................................................................IV-23

1.32 PS Switch Wire, Remote Switch ............................................................................IV-23

1.33 High-Voltage Power Supply PCB Assy...................................................................IV-24

1.34 Low-Voltage Power Supply PCB Assy ...................................................................IV-24

1.35 Toner Cartridge (EP-ED Cartridge) .........................................................................IV-25

1.36 Paper Tray..............................................................................................................IV-25

CHAPTER V MAINTENANCE AND SERVICING

1 . PERIODICAL REPLACEMENT P ARTS ............................................................................. V-1

2 . CONSUMABLE PARTS ST ANDARD ENDURANCE T ABLE ............................................... V-1

3 . LIST OF ST ANDARD TOOLS............................................................................................. V-2

4 . LIST OF LUBRICANTS AND CLEANERS ......................................................................... V-3

CHAPTER VI TROUBLESHOOTING

1. INTRODUCTION ............................................................................................................... VI-1

1.1 Initial Check............................................................................................................ VI-1

1.2 Basic Procedure ..................................................................................................... VI-2

2. TEST PRINTING AND MECHANICAL CHECK................................................................. VI-2

2.1 T est Printing............................................................................................................ VI-2

3 . IMAGE DEFECTS ............................................................................................................ VI-3

3.1 Image Defect Examples ......................................................................................... VI-3

3.2 Troubleshooting Image Defects ............................................................................... VI-4

4. TROUBLESHOOTING OF MALFUNCTIONS .................................................................. VI-11

5. TROUBLESHOOTING PAPER TRANSPORT PROBLEMS ............................................. VI-19

5.1 Paper Jams .......................................................................................................... VI-19

5.2 Incomplete Paper Feed ......................................................................................... VI-22

6. OPERATION................................................................................................................... VI-23

6.1 Line Inspection Mode Procedure........................................................................... VI-23

6.2 DRAM T est ........................................................................................................... VI-25

7. ST ATUS MESSAGE LIST............................................................................................... VI-26

APPENDICES

1. Engine Block Diagram ....................................................................................................... A-1

2. Paper Feed/Size-SW PCB Circuitry Diagram (1/1) ............................................................. A-2

3. Main PCB Circuitry Diagram (1/7) ...................................................................................... A-3

4. Main PCB Circuitry Diagram (2/7) ...................................................................................... A-4

5. Main PCB Circuitry Diagram (3/7) ...................................................................................... A-5

6. Main PCB Circuitry Diagram (4/7) ...................................................................................... A-6

7. Main PCB Circuitry Diagram (5/7) ...................................................................................... A-7

8. Main PCB Circuitry Diagram (6/7) ...................................................................................... A-8

9. Main PCB Circuitry Diagram (7/7) ...................................................................................... A-9

10. Control Panel PCB Circuitry Diagram (1/1) ....................................................................... A-10

11. Scanner LD PCB Circuitry Diagram (1/1).......................................................................... A-11

I - 1

CHAPTER I GENERAL

1. FEATURES

A. This high-speed, non-impact (low-noise) printer is based on electrophotography, electronics

and laser technology.

B. The printer is compact and easy to carry. The internally-storable, front-loading paper

cassette enables you to save an occupation space for the machine; the printer can now
be installed in a smaller place.

C. The charging roller, developing cylinder, photosensitive drum and cleaner of the printer

are combined into a single assembly called an ”EP-ED cartridge”. The cartridge can be
replaced by the user when necessary without a need of service call. High printing quality
is maintained by a simple cleaning procedure.

D. Laser beam safety is designed into the printer. The printer is approved by the US Center

for Devices and Radiological Health (CDRH).
E. Paper can be fed in two ways, by the multi-purpose paper feed tray and paper cassette.
F. Maintenance is easy with print component units which are directly detachable, and they

require no adjustment after reassembly.

2. SPECIFICATIONS

(1) Type Desktop page printer
(2) Printing method Electrophotography (single-component dry toner)
(3) Printing speed

Cassette feed 12 pages/minute (A4/Letter size by cassette feed)

10.2 pages/minute (Legal size)

(4) First print time Approx. 20 seconds

(A4 size by face-down print delivery from the paper cassette)
(5) Warm-up (WAIT) time Max. 1 minute at 20°C (68°F)
(6) Optical system

Laser Semiconductor laser

Output power : 5mW max.

Wave length

: 780 nm

Scanning system Rotating six-faced polygon mirror

(7) Resolution

Horizontal 600 dots/inch and high resolution control (HRC)
Vertical 600 raster lines/inch

I - 2

(8) Printing system

Photosensitive drum OPC
Charging Charging Roller
Exposure Laser scanning system
Development Toner projection development system
Paper feed Cassette or manual feed
Image transfer Roller method
Separation Natural(utilizing a small drum radius), Static charge eliminator
Fixing Heated fixing roller
Toner supply Included in the replaceable EP-ED cartridge
Life expectancy 6000 pages/cartridge

(9) Paper

Cassette feed Plain paper for Letter, Legal, A4, ISO B5, A5, ISO B6, A6,

Executive (A4 or letter size paper with the print density set at
level 8 with 4% coverage, recommended: 60 g/m

105 g/m )

and Envelope (com10, monarch, C5, DL, ISO B5)

Multi-purpose Tray Plain paper of 90 x 148 mm 216 x 356 mm (recommended:

60g/m 135 g/m , overhead projector (OHP) film, postcards,
label stock and envelopes (specified sizes)

(10) Cassette (Tray 1)

Universal cassette A4, Letter, Legal, ISO B5, Executive, A5, ISO B6, and A6
Maximum load height 55 mm (500 sheets of 80 g/m paper)
Feedable paper type 60 105 g/m

Envelopes 40 envelopes
(11) Print delivery Face-down or (face-up)
(12) Print delivery tray capacity

Face-down 250 sheets (80 g/m )

Face-up Discharge only

2

2

2

2

2

2

2

I - 3

Effective printable area is referred to as a area within which is guaranteed the printing of all

interface signal data on a hard copy without any omission.

The tables below shows the effective printable area for each paper size.

SIZE A (mm) B (mm) C (mm) D (mm)

COM-10
MONARCH

DL

B5 (ISO)

C5

104.8 241.3 96.3

232.8

98.4 190.5 89.9 182.0

110.1 221.0 101.6 212.5

162.2 228.6 154.1 220.1

176.0 250.0 167.5 241.5

E (mm)

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

SIZE A (mm) B (mm) C (mm) D (mm)

A 4
Letter

Legal

Executive

B 6 (ISO)
A 6

B 5 (ISO)

A 5

210.0 297.0 203.2

288.5

215.9 279.4 207.4 270.9

215.9 355.6 207.4 347.1

176.0 250.0 167.5 241.5

184.2 266.7 175.7 258.2

148.0 210.0 139.5 201.5

125.0 176.0 116.5 167.5

105.0 148.0 96.5 139.5

E (mm)

3.39 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

4.23 ± 1.0

(The sizes above are nominal sizes according to ISO.)

An A4 sheet accepts 80 PICA-pitch characters (203.2mm).

(13) Effective printing area

Printable area

E

D

B

C

E

E

A

E

Figure 1.1 Printable Area

Table 1.2 Envelope

Table 1.1 Plain Paper

I - 4

(14) Standard interfaces Automatic interface selection

• Centronics, Bi-directional parallel

• RS-232C serial
Baud rate : 150, 300,1200, 2400, 4800, 9600

19200, 38400, 57600 bps
Stop bit : 1 bit
Start bit : 1 bit or 2 bits
Data length : 7 bits or 8 bits
Parity : Odd, Even, or None
Protocol : Xon/Xoff or DTR

(15) Emulation Automatic emulation selection

• HP Laser Jet 5 (PCL Level 6)

• EPSON FX-850

• IBM Proprinter XL

• BR-Script level 2 (PostScript language emulation interpreter)

• HP- GL

(16) CPU MB86832
(17) Resident fonts 75 scalable fonts and 12 bitmapped fonts

HP Laser Jet 5, EPSON FX-850, IBM Proprinter XL
Scalable Fonts:

Intellifont Compatible Fonts:

• Albertville, Extrabold

• Antique Oakland, Oblique, Bold

• Brougham, Oblique, Bold,
Bold Oblique

• Cleveland Condensed

• Connecticut

• Guatemala Antique, Italic, Bold,
Bold Italic

• Letter Gothic, Oblique, Bold

• Maryland

• Oklahoma, Oblique, Bold,
Bold Oblique

• PC Brussels Light, Light Italic, Demi,
Demi Italic

• PC Tennessee Roman, Italic, Bold,
Bold Italic

• Utah, Oblique, Bold, Bold Oblique

• Utah Condensed, Oblique, Bold,
Bold Oblique

Bitmapped Fonts (Portrait and Landscape):

• Letter Gothic 16.66 Medium, Italic, Bold, Bold Italic

• OCR-A

• OCR-B

Windows 3.1 Compatible Fonts:

• Tennessee Roman, Italic, Bold,
Bold Italic

• Helsinki, Oblique, Bold, Bold Oblique

• BR Symbol

• W Dingbats
BR-Script Fonts:

• Atlanta Book, Book Oblique, Demi,

Demi Oblique

• Copenhagen Roman, Italic, Bold,
Bold Italic

• Portugal Roman, Italic, Bold, Bold Italic

• Calgary Medium Italic
Brother Original Fonts:

• Bermuda Script

• Germany

• San Diego

• US Roman

I - 5

(18) RAM 2M bytes (expandable to 26M bytes)
(19) Font cartridge/card slots Two slots

One font cartridge slot and one font card slot

(20) Power souse USA and Canada : AC 110 to 120 V, 60 H

Z

Europe and Australia : AC 220 to 240 V, 50 HZ

(21) Power consumption Printing(peak) 115V/230V : 640 WH/1.010 WH or less

Printing(average): 500 WH or less
Stand-by : 80 WH or less
Sleep : 20 WH o r less

Note:

- The peak figure of power consumption is worked out when the halogen heater lamp is
turned ON.

- The peak figure of power consumption is worked out excluding inrush current value.

- Be sure that the peak figure of power consumption is reference value and should be
used inside the Brother offices only.

(22) Noise Printing : 4 9 dB A or less

Stand-by : 40 dB A or less
(23) Dimensions (W x H x D) 371.6 x 326.5 x 393 mm (14.6 x12.9 x 15.5 inches)
(24) Weight Approx. 15 kg (32.6 Ibs)
(25) Environmental conditions

Operating Temperature10 ~ 32.5°C
environment Relative humidity 20 ~ 80%RH

(No condensation allowed)

Air pressure 613 ~ 1013 hPa

(0 ~ 2,500 m above sea level)

Non-operating Temperature0 ~ 35°C
environment Relative humidity 10 ~ 80%RH

(No condensation allowed)

Storage conditions

• Printer Temperature

• Albertville, Extrabold

• Antique Oakland, Oblique, Bold

• Cleveland Condensed

• Conecticut

• Guatemala Antique, Italic, Bold, Bold Italic

• Letter Gothic, Oblique, Bold

• Maryland

• Oklahoma, Oblique, Bold, Bold Oblique

• Utah, Oblique, Bold, Bold Oblique

• Utah Condensed, Oblique, Bold,
Bold Oblique

• Bermuda Script

• Germany

• San Diego

• US Roman

BR-Script Level 2 Mode
Scalable Fonts:

• Atlanta Book, Book Oblique, Demi,
Demi Oblique

• Brussels Light, Light Italic, Demi,
Demi Italic

• Brougham, Oblique, Bold, Bold Oblique

• Helsinki, Oblique, Bold, Bold Oblique

• Helsinki Narrow, Oblique, Bold,
Bold Oblique

• Copenhagen Roman, Italic, Bold,
Bold Italic

• Portugal Roman, Italic, Bold, Bold Italic

• Tennessee Roman, Italic, Bold, Bold Italic

• Calgary Medium Italic

• BR Symbol

• BR Dingbats

PR99017

I - 6

• EP-ED cartridge Temperature
Normal (2.45 years max.)

0 ~ 35°C

Severe (0.05 years max.)

High Low
35°C ~ 40°C -20°C ~ 0°C

Temperature change (within 3 minutes)

High Low
40°C 15°C -20°C 25°C

Relative humidity

Normal (2.45 years max.)

35 ~ 85%RH

Severe (0.05 years max.)

High Low

85 ~ 95%RH 10 ~ 35%RH
Air pressure 613 ~ 1013 hPa
Maximum total storage time: 2.5 years including used time

3. SAFETY INFORMATION

3.1 Laser Safety (110 ~ 120V Model only)

This printer is certified as a Class 1 laser product under the US Department of Health and
Human Services (DHHS) Radiation Performance Standard according to the Radiation Control
for Health and Safety Act of 1968. This means that the printer does not produce hazardous
laser radiation,

Since radiation emitted inside the printer is completely confined within the protective housings
and external covers, the laser beam cannot escape from the machine during any phase of

Normal (total storage time x 9/10)

0 ~ 35°C

Severe (total storage time x 1/10)

High Low

35°C ~ 60°C -20°C ~ 0°C

Temperature change (within 3 minutes)
High Low

60°C 15°C -20°C 25°C
Relative humidity

Normal (total storage time x 9/10)

35 ~ 85%RH

Severe (total storage time x 1/10)

High Low

85 ~ 95%RH 10 ~ 35%RH
Air pressure 613 ~ 1013 hPa
Total storage time 0.5 years

I - 7

3.2 CDRH Regulations (110 ~ 120V Model only)

The center for Devices and Radiological Health (CDRH) of the US Food and Drug
Administration implemented regulations for laser products on August 2, 1976. These
regulations apply to laser products manufactured from August 1, 1976. Compliance is
mandatory for products marketed in the United States. The label shown below indicates
compliance with the CDRH regulations and must be attached to laser products marketed in
the United States.

Caution: Use of controls, adjustments or performance of procedures other than those

specified in this manual may result in hazardous radiation exposure.

Figure 1.2

MANUFACTURED :
BROTHER INDUSTRIES, LTD.
15-1, Naeshiro-cho, Mizuho-ku Nagoya 467, Japan.
This product complies with FDA radiation
performance standards , 21 CFR chapter 1
subchapter J.

3.3 Additional Information

When servicing or adjusting the optical system of the printer, be careful not to place
screwdrivers or other reflective objects in the path of the laser beam. Be sure to take off any
personal accessories such as watches and rings before working on the printer. A reflected
beam, though invisible, can permanently damage the eyes.

Since the beam is invisible, the following label is attached to the inside of covers where
danger of exposure to laser radiation exist.

Figure 1.3

I - 8

9 AC inlet

10 Face-up print delivery port
11 Fan outlet port
12 Rating label
13 Optional I/O slot
14 RS-232C interface connector
15 Centronics interface connector
16 Optional interface connector

4. PARTS OF THE PRINTER

4.1 External Views

1 Upper cover
2 Control panel
3 MP tray
4 Tray 1
5 Tray 2 (Option)
6 Font card slot
7 Font cartridge slot
8 Power switch

2

4

10

11

6

3

8

5

7

1

9

15

13

16

12

14

Figure 1.4

I - 9

1 Registration rollers
2 EP-ED cartridge
3 Photosensitive drum
4 Laser scanner unit
5 Transfer unit
6 Face-down tray
7 Print-delivery path
8 Fixing unit

9 Low-voltage power supply assy

10 High-voltage power supply assy
11 Paper cassette (Tray 1)
12 Pick-up rollers
13 MP tray
14 Control panel

9

13

8

1

2

3

4

5

12

11

7

6

10

4.2 Cross Sectional View

14

Figure 1.5

I - 10

5. STORAGE AND HANDLING OF EP-ED CARTRIDGES

An EP-ED cartridge is influenced by the storage conditions even if it is sealed in its package,
so its life depends on the way in which it is used or stored. EP-ED cartridges should be
handled carefully.

5.1 Storage of Sealed EP-ED Cartridges

When storing sealed EP-ED cartridges in a warehouse or workshop, the storage conditions
shown in (25) Environmental conditions on Page 1-5 must be met. Follow the instructions
below:

1) Avoid direct sunlight.

2) Do not store cartridges on a surface that is subject to vibration.

3) Do not hit or drop the packages containing cartridges.

4) The cartridges should be stored horizontal when they are removed from the body (with
their label side upside).

5) Avoid putting the cartridges near a CRT screen, a disk or a floppy disk (to keep their data
from being destroyed).

5.2 Storage of Unsealed EP-ED Cartridges

Each EP-ED cartridge contains a photosensitive drum that has an organic photoconductor
(OPC) which deteriorates when exposed to strong light. It also contains toner. The user,
therefore, should be fully informed about the correct storage and handling of EP-ED
cartridges.

(1) Storage requirements

1) Avoid places exposed to direct sunlight or near a window. Do not leave an EP-ED
cartridge in a car in warm or hot weather even if it is in its storage box.

2) Avoid places with a too-high or too-cool temperature and/or humidity. Also avoid
places exposed to sudden temperature or humidity changes (such as near an air
conditioner outlet).

3) Avoid dusty places or places exposed to ammonia fumes or other harmful fumes.

4) Do not store an EP-ED cartridge in a temperature above 40°C.

(2) EP-ED cartridge life

The effective life of an EP-ED cartridge is 2.5 years from the date of manufacture
(printed on the cartridge.) The expiry year and month (date of manufacture plus 2.5
years) is shown on the EP-ED cartridge box. An EP-ED cartridge used after the expiry
may produce low-quality printing, so a cartridge should be used within the stated
period.

II - 1

CHAPTER II THEORY OF OPERATION

This chapter describes the printer functions, the relationship between the electrical systems and
mechanical systems, and the timing of operations. Striped conduits ( ) indicate mechanical
linkages; solid thin arrows ( ) appearing with a signal name indicate the transmission of
single control signals and outlined thick arrows ( ) indicate the transmission of groups of
signals.

1. BASIC OPERATIONS

1.1 Mechanical Configuration

The printer functions can be divided into four blocks: the laser/scanner system, the image
formation system, the paper pick-up/feed system and the control system.

Figure 2.1

Expansion memory
(SIMM)

Font cartridge/card

Optional I/O
(MIO)

External Device

Control panel

IMAGE FORMATION SYSTEM

Cleaning unit

Photosensitive drum

Developing

unit

Laser/scanner
unit

LASER/SCANNER
SYSTEM

Transfer

separation

unit

Delivery rollers

Fixing unit

Feeder

Tray 1

Tray 2

(Option)

MP tray

Main PCB

CONTROL SYSTEM

PAPER PICK-UP/FEED SYSTEM

II - 2

1.2 Main Drive

The power necessary for driving the printer is supplied by the main motor, the paper feed motor
and the scanner motor.

The main motor is controlled by the main motor drive signal (MDRIVE) output from the main
PCB, and the paper feed motor is controlled by the paper feed motor drive signal output from
the main PCB, and the scanner motor is controlled by the scanner motor drive signal (SDRIVE)
output from the main PCB.

Figure 2.2

Main motor

Main motor drive signal (MDRIVE)

Main PCB

Drum gear

Photosensitive
drum

Fixing unit

Paper delivery
rollers

Paper feed motor

Paper feed motor drive signal

MP tray pick-up roller solenoid drive signal (MPSOL)

MP tray pick-up
roller solenoid

MP tray
pick-up roller

Tray1 pick-up roller solenoid drive signal (PUCL1)

Tray1 pick-up
roller solenoid

Tray1
pick-up roller

Scanner motor drive signal (SDRIVE)

Scanner motor

Scanning mirror

Scanner unit

Note: There are cases, in the following pages, that

a main motor is referred to as a DC motor, but
they are identical.

II - 3

1.3 Basic Sequence of Operations

Timing for two consecutive prints on A4 paper.

Power on Print

WAIT STBY PRINT

Ready lamp

Fixing heater

Main motor

170 C control 190 C

STBY

control

170 C

control

Scanner motor

Paper feed
motor

Pick-up roller
solenoid

Laser diode

Registration
sensor

0.15 sec

0.15 sec

1.88 sec

1.73 sec

3.18 sec

Figure 2.3

II - 4

2. LASER/SCANNER SYSTEM

In response to the print signal transmitted from the external device, the main PCB generates the
drive signals (DATA,VOFF) for the laser diode and sends the signals to the scanner unit.

The laser diode in the scanner unit generates a laser beam modulated by DATA.

The modulated laser beam is aligned into a parallel beam by a collimator lens and a cylindrical
lens and then brought to the scanning mirror which is rotating at a constant speed.

The laser beam reflected by the scanning mirror focuses on the photosensitive drum via the
focusing lenses arranged in front of the scanning mirror.

The path of the beam coming through the focusing lenses is reflected by the reflective mirror.

As the scanning mirror rotates at a constant speed, the laser beam scans the photosensitive
drum at a constant speed.

As the photosensitive drum rotates at a constant speed and the laser beam scans the drum, an
images is formed on the drum.

Scanner driver

Collimator lens

Cylindrical lens

Scanner motor

Scanning mirror

Focusing lenses

Beam detect mirror

Optical sensor

To external device

Main PCB

SBD DATA VOFF

Figure 2.4

II - 5

3. IMAGE FORMATION SYSTEM

3.1 Outline

The image formation system is the main part of the printer. The print information, after input from
the video controller circuit into the engine controller circuit as a TVDO signal, forms a toner image
on the photosensitive drum.

Then the toner image is transferred onto the paper by the transfer charging roller. The image
formation system is composed of the photosensitive drum the charging unit, the developing unit
and the cleaning unit.

3.2 Printing Process

The major part of the image formation system is contained in the cartridge, as shown in Figure

2.5.

The cartridge used by the printer has a seamless photosensitive drum with the structure shown
in Figure 2.6. The outer layer of the drum consists of an organic photoconductor (OPC); the base
is aluminum.

The printing process can be divided into five major stages:

Figure 2.5

Base

Photoconductive layer

Laser beam

Developing cylinder

Primary charging roller

Cleaning blade

Photosensitive drum

Static charge eliminator

Cartridge

Transfer charging roller

Blade

Figure 2.6

1. Electrostatic latent image formation stage
Step 1 Primary charge (-)
Step 2 Scanning exposure

2. Developing stage
Step 3 Development

Paper

II - 6

3. Transfer stage
Step 4 Transfer (+)
Step 5 Separation

4. Fixing stage
Step 6 Fixing

5. Drum cleaning stage
Step 7 Drum cleaning

Electrostatic latent image
formation stage

Transfer stage

Fixing stage

Drum cleaning stage

Developing stage

Paper path
Direction of drum rotation

2. Scanning exposure

1. Primary charge

7. Drum cleaning

Print delivery

6. Fixing

5. Separa­ tion

4. Transfer

Registration

Multi-purpose tray feed

Cassette feed

3. Develop
ment

Figure 2.7

3.2.1 Electrostatic latent image formation stage

This stage has two steps, which together produce a pattern of electrical charges on the
photosensitive drum.

At the end of the stage, negative charges remain in the unexposed ”dark” area. Charges are
absent from the ”light” areas, where the laser beam struck (exposed) the drum surface.

Since this image of negative charges on the drum is invisible to the eye, it is called an
”electrostatic latent image”.

Time (t)

0

-100

Exposed
area

Unexposed
area

Primary
charge
(step 1)

Scanning
exposure
(step 2)

Primary
charge
(step 1)

Transfer
(step 4)

Surface potential (V)

-500

Figure 2.8

II - 7

Step 1 Primary charge

As preparation for latent image formation, a uniform negative potential is applied to the
photosensitive drum surface. The printer uses the charging method that directly charges the
drum for the primary charge.

The primary charging roller consists of conductive rubber. In addition to DC bias, AC bias is
applied to the primary charging roller to keep the potential on the drum surface uniform. This DC
bias is changed with the developing DC bias.

This charging method has advantages such as lower applied voltage, less ozone generation,
etc., compared with the corona charge system.

Step 2 Scanning exposure

Figure 2.10

+++

___

Laser beam

Unexposed area

Exposed area

When the laser beam scans the drum surface, it causes the charge to be neutralized in the areas
struck by the beam. Areas on the drum with no charge form the electrostatic latent image.

DC bias

AC bias

Photosensitive drum

Primary charging roller

,,

,

,

,,

,,

,

,

,

,,

,,

,,

,

,

,,

Figure 2.9

II - 8

3.2.2 Developing stage

Development places particles of toner onto the areas of the drum that have been cleared of
charge by the laser beam. This makes a visible image. This printer uses the toner projection
development method with a single-component toner.

Blade

Stirrer

Developing cylinder

Cylinder
Magnet

DC bias

AC bias

Photo-

sensitive

drum

Figure 2.11

Note: The charges on the light areas on the photosensitive drum are shown as positive in this

figure. Actually they are negative, but they are more positive than the developing
cylinder and explanation is simplified by regarding them as positive.

As shown in Figure 2.11, the developing unit consists of a developing cylinder and rubber blade.
The developing cylinder rotates around a fixed internal magnet. The single-component toner
consists of magnetite and a resin binder, and is held to the cylinder by magnetic attraction. The
toner is an insulator, and acquires a negative charge by friction due to the rotation of the cylinder.

The areas on the drum that were exposed to the laser beam have a higher potential (are less
negative) than the negatively charged toner particles on the developing cylinder. When these
areas approach the cylinder, the potential difference projects the toner particles onto them. This
is called toner projection, and the latent image on the drum becomes visible.

Developing cylinder
surface potential

Drum surface
potential
(exposed area)

DC bias
Drum surface

potential
(unexposed area)

Time t

+V

0

-V

Voltage (V)

Figure 2.12

An AC bias is applied to the developing cylinder to help project the toner particles to the drum
surface and improve the contrast of the printed image. The center voltage of the AC bias (1600
Vp-p) varies with the DC bias voltage.

The IMAGE DENSITY ADJUSTMENT signal (sent from the Engine CPU to the high-voltage
power supply) changes the DC bias, and thus the potential difference between the cylinder and
drum. This changes the density of the print.

This printer has a stirring mechanism to supply toner in the cartridge smoothly to the cylinder.

Step 3 Development

II - 9

A positive charge applied to the back of the paper attracts the negatively charged toner particles
to the paper. The printer accomplishes transfer by using the charging roller method. Advantages
compared with the corona transfer method are as follows:

• Low transfer voltage that is less than half that for corona transfer.

• Less ozone generation.

• The paper is supported by the transfer charging roller and photosensitive drum, so feed is

more stable.

Reference:

If the image on the photosensitive drum is not completely transferred to the paper due to
jamming, etc., the toner may adhere to the transfer charging roller. The printer removes the toner
from the transfer charging roller by switching the transfer voltage between positive and negative
in sequence. During wait, initial rotation, and last rotation, the printer sets the primary DC voltage
to zero, and sets the charge on the drum to zero. In this case, the transfer voltage is made
negative to remove the negatively-charged toner on the transfer charging roller to the drum. The
transfer charging roller is thus cleaned.

3.2.3 Transfer stage

In the transfer stage, the toner image is transferred from the drum surface to the paper.

Step 4 Transfer

Figure 2.13

The stiffness of the paper causes it to separate from the drum. (Curvature separation)
To stabilize the paper feed and prevent small white circles from appearing in the printed image

at low temperature and humidity, the charge on the back of the paper is reduced by the static
charge eliminator after transfer.

Figure 2.14

Photo-

sensitive

drum

Paper

Transfer charging roller

Photo-

sensitive

drum

Paper

Transfer char

ging roller

Static charge
eliminator

Step 5 Separation

II - 10

3.2.4 Fixing stage

The toner image transferred to the paper in the transfer stage is held only by electrostatic
attraction and slight physical adhesion, so even a light touch will smear the image.

In the fixing stage, the toner image is fixed by heating the paper and applying pressure. This
fuses the toner particles to the paper to make a permanent image.

Figure 2.15

Step 6 Fixing

The upper roller surface is PFA-coated. The upper and lower roller surfaces are grounded via
a diode to prevent the negative potential of the upper roller becoming higher than that of the
lower roller, resulting in the toner being drawn to the lower roller, and adhering to the lower roller
surface.

3.2.5 Drum cleaning stage

In the transfer stage, not all the toner is transferred to the paper. Some remains on the
photosensitive drum. This residual toner is cleaned off in the drum cleaning stage so that the
next print image will be clear.

Step 7 Drum cleaning

Photo-

sensitive

drum

Prior to the next printing, the residual toner on the drum surface is scraped away by the cleaning
blade to clean the drum surface. The removed toner is collected in the cleaner container.

Cleaning blade

Sweeper strip

Cleaner container

Figure 2.16

Upper fixing roller

Toner

Paper

Lower fixing roller

Halogen heater

II - 11

3.3 Operation

When the engine controller circuit receives a print signal (PRINT) or a pre-feed signal (PRFD)
from the video controller circuit, the engine controller circuit drives the main motor to rotate the
photosensitive drum.

After the drum surface is charged negatively by the primary charge roller, the laser beam
modulated by a DATA signal scans the drum surface to from a latent image on the drum.

The latent image formed on the drum surface is converted into a visible image by the toner on
the developing cylinder and then image is transferred onto the paper by the transfer roller unit.
Then the residual toner is removed from the drum surface with the cleaner blade.

The cartridge also has a toner sensor. When the output from this sensor falls below a certain
level, it warns that the EP-ED cartridge will be out of toner with an alarm.

Primary charge (AC) drive (HV1AC)
Primary charge (DC) drive (HV1DC)

Developing bias (AC) drive (DBAC)
Developing bias (DC) drive (DBDC)

Transfer charger 1 drive (HVT1)
Transfer charger 2 drive (HVT2)
Transfer charger 3 drive (HVT3)
Transfer charger 4 drive (HVT4)

Toner sensor signal 1 (TONER 1)
Toner sensor signal 2 (TONER 2)

Main
PCB

Scanner unit

EP-ED cartridge

Transfer
roller

High-voltage
power supply
PCB

Laser beam

Reflection mirror

Scanner motor drive signal (SDRIVE)

Laser diode drive signal (DATA)

Figure 2.17

II - 12

4. PAPER PICK-UP/FEED SYSTEM

4.1 Outline

If a tray1 paper pick-up roller solenoid drive signal (PUCL1) is input to the circuit while the paper
feed motor is rotating, the paper pick-up solenoid comes on and the paper pick-up roller solenoid
is engaged. As a result, the paper pick-up roller rotates to feed paper down to the photosensitive
drum.

The paper position is controlled by the registration sensor so that the leading edge of the paper
is aligned with the leading edge of the image on the photosensitive drum. After this operation,
the paper is deliveried to the face down tray via the fixing unit. Paper ejection is detected by the
paper ejection sensor; if printed paper has not reached or not cleared the paper ejection sensor
in a specified time, the printer judges that a paper jam has occurred. In this case a paper jam
is noticed to the external devise by a status signal.

Figure 2.18

Main PCB

Paper ejection sensor

Fixing rollers

Transfer roller

Main motor

Photosensitive

drum

Registration

sensor

Tray1 Pick-up

roller solenoid

Paper-

feed

motor

MP tray Pick-up

roller solenoid

MP tray

paper empty sensor

Tray paper

empty sensor

MP tray paper empty sensor signal (PEMP)

MP tray pick-up roller
solenoid drive signal (MPSOL)

Paper feed motor drive signal

Tray1 pick-up roller solenoid drive signal (PUCL1)

Tray1 paper empty sensor signal (PETRAY1)

Registration sensor signal (REGIST)

Main motor drive
signal (MDRIVE)

Paper ejection sensor signal (EJECT)

II - 13

Figure 2.19

0.15 sec

2.17 sec

1.73 sec 3.18 sec

Main motor

Paper feed
motor

Registration
sensor

Paper empty
sensor

Pick-up roller
solenoid

Paper ejection
sensor

STBY PRINT STBY

PRNT or PRFD

0.15 sec

4.2 Cassette Feed

When the fixing rollers reach the specified temperature while a cassette with paper is in the
printer, the READY lamp changes from flashing to lighting.

When the engine controller circuit receives PRNT or PRFD signal from the video controller
circuit, the paper feed motor starts rotation. About 0.2 seconds later, the printer actuates the
tray1 pick-up roller solenoid and the pick-up roller makes one rotation. This feeds paper to the
photosensitive drum.

Timing chart for the pick-up one sheet

II - 14

4.3 MP Tray Feed

The timing of the MP tray feed is identical to the timing of the cassette paper feed except for
the following points:

(1) The paper empty sensors are different.

Cassette feed : Tray1 paper empty sensor
MP tray feed

: MP tray paper empty sensor

(2) The pick-up roller solenoids are different.

Cassette feed : Tray1 pick-up roller solenoid
MP tray feed

: MP tray pick-up roller solenoid

0.15 sec 0.15 sec

Main motor

Paper feed
motor

Registration
sensor

Paper empty
sensor

Pick-up roller
solenoid

Paper ejection
sensor

STBY PRINT STBY

PRNT or PRFD

0.84 sec

Figure 2.20

II - 15

4.4 Paper Jam Detection

The printer has a registration sensor and a paper eject sensor at the paper outlet to detect
whether the printed paper has been fed correctly. A paper jam is detected by whether the paper
is present at the sensor at the check periods programmed in the engine CPU memory. If the
engine CPU detects a paper jam, the main motor, paper feed motor and scanner motor is turned
off immediately and the jam status is transmitted to the video controller circuit.

A paper jam is detected in any of following conditions:

1) Paper exists at the paper ejection sensor or the registration sensor when power is
switched on. (JAM REAR or JAM INSIDE)

2) Paper has not reached the registration sensor within a specified time (JAM TRAYS).

3) Printed paper has not passed through the registration sensor within a specified time (JAM
INSIDE (1) ).

4) Printed paper has not reached the paper ejection sensor within a specified time (JAM
INSIDE (2) ).

5) Printed paper has not passed through the paper ejection sensor within a specified time
(JAM REAR).

Figure 2.22

Figure 2.21

Main motor

Registration
sensor

Pick-up
solenoid

STBY PRINT

Jam check

JamNormal

3.75 sec3.75 sec

Jam

3.67 sec3.67 sec

Normal

Main motor

Registration
sensor

Paper feed
motor

Jam check

STBY PRINT

Jam inside (1)

Jam tray

II - 16

STBY PRINT

JamNormal

1.88 sec1.88 sec

Main motor

Paper ejection
sensor

Paper feed
motor

Jam check

Jam inside (2)

Figure 2.23

Jam rear

STBY PRINT

JamNormal

7.17 sec

7.17 sec

Main motor

Paper ejection
sensor

Paper feed
motor

Jam check

Figure 2.24

III - 1

CHAPTER III ELECTRICAL SYSTEM

Electric signal levels are expressed by ”High” (approximate the supply voltage) or ”Low”
(approximate 0V). Signals with hyphen or slash, such as -FSRD or FSRD/, are low-active and
signals without hyphen or slash, such as FSRD, are high-active signals.

1. MAIN PCB

1.1 Outline

The Main PCB consists of the Video Controller Circuit and the Engine Controller Circuit.
The Video Controller Circuit performs the following functions.
(1) Converts data received from an external device, such as a personal computer, through

Centronics parallel interface or RS-232C serial interface into video data and transfers it
to the Engine controller circuit.

(2) Displays the current printer status in LED and LCD, and enables settings from the control

panel.

The operation sequence of the printer controlled by a microprocessor in the Engine Controller
Circuit. The Engine Controller Circuit outputs signals to drive the various loads on the laser
diode, scanner motor, main motor, etc. according to the print commands and image data from
the external device.

Figure 3.1 Main PCB Block Diagram

FONT
CARTRIDGE

IC CARD
(PCMCIA)

MIO BOARD

Regurator

+24V

PC

PC

CDCC (bolse) IF

RS-232C IF

ASIC
MB87F1610

Video controller

Engine controller

Engine CPU

M38063

+24V

+5V

GND

CONTROL PANEL

Low-voltage
Power Supply

Gate Array
µPD65632GF­(IO PORT. ENGINE)

MASK ROM

32M mask 2 4MB

DRAM

16M 4 8MB

DRAM (SIMM 2 slots)

64MBmax.

EEPROM

24CO4 4Kbit

Main CPU

MB86832

Main PCB

MIO RELAY

(CONNECTOR)

PCB

III - 2

1.2 Video Controller Circuit

(1) CPU block

CPU(#33) MB86832-100 manufactured by Fujitsu
RISC chip
Clock speed: 19.6608 MHz
Appearance: 178-pin QFP
Voltage: 3V

(2 ) ASIC/Gate Array Block

• #19 MB87F1610(Fujitsu) - 240-pin QFP
Controls the address decoder, timers and interfaces (Centronics and RS-232C).

• Controls HRC(High Resolution Control), GSC(Gray Scale Control) and economy mode,
drivened by 3V.

• #3 µPD65632GF - 100-pin QFP
Controls the I/O ports and others.

(3) Font Cartridge/Card Block

• Font cartridge (option)
The font cartridge has a 32MB memory area and is controlled by the 16-bit bus.
The address bus a buffer LS245 and the data bus, a buffer LCX245.

• Font Card (option)
The font card has a 32MB memory area and is controlled by the 16-bit bus.
The card is supplied with 12V power because the flash card requires 12V power supply
when writing or erasing data.
The address bus is buffered by LS245 and the data bus, is buffered by LCX245.

(4) Centronics/RS-232C interface block

• Centronics parallel interface
Data transmission and reception are controlled by the MB87F1610 (#19).

• RS-232C
Data transmission and reception are controlled by the MB87F1610 (#19).
The ADM202JRN (#35) serves as driver/receiver.

(5) SIMM block

• SIMM (Single-Inline-Memory-Module) allows memory extension up to 72MB

• 2 SIMM sockets are available.

• SIMM should be of 72-pin type and its access time should be less than 70 ns.

• 6 types of SIMM (1MB, 2MB, 4MB and 8MB) can be combined:
1MB MH25632BJ-7 (MITSUBISHI), HB56D25632B-7A (HITACHI)
2MB MH51232BJ-7 (MITSUBISHI), HB56D51232B-7A (HITACHI)
4MB MH1M32EJ-7 (MITSUBISHI), HB56A132BT-7A (HITACHI)
8MB MH2M32EJ-7 (MITSUBISHI), HB56A232BT-7A (HITACHI)

1) The SIMMs have its printed marking on the PCB by silk screen: SLOT1 and SLOT2,

respectively. The SIMMs should be set in the order of SLOT1 - SLOT3.

III - 3

3) The attached Printer SIMM map shows the memory map for 4 SIMMs combined.

(6 ) ROM block

ROMs store the CPU control program and font data. ROMs are two 32Mbit masked ROMs.
Optional sockets are available for two 8Mbit EPROM (µPD27C8000DZ-120 - NEC or equivalent)

for expansion.
ROM access time should be less than 120nsec.

(7 ) DRAM block

DRAMs are used for receiving buffer or working area of the CPU. The DRAM block contains four
16Mbit DRAMs, thus having 8MB memory capacity in total.

The refreshing method is CBR (Cas Before Ras).
DRAM access time should be less than 80nsec.

III - 4

0000_0000
0040_0000
0080_0000

0100_0000

0200_0000

0400_0000

0600_0000

0800_0000

0B00_0000

0C00_0000

0E00_0000

0FC0_0000
0FD0_0000

(256MB)

ROM

(4 bunk)

Font card

(64MB)

Font cartridge

(16MB)

ROM3

(128MB)

Ghost for CS1#

CPU

DRAM

(MAX 128MB)

64MB x 8 bunk

Reverved

(16MB x 4)

MIO / EOT

ASIC

Ghost for CS4#

There are 4 CS terminals for CSROM#0 - CSROM#3.
2MB or 4MB is selectable from CSROM#0 - CSROM#2.
If the both are selected, it will become one memory space
and ROM#0 supports upto 16MB. CSROM#3 is a rest of
the memory space with 256MB

$5E00_0000

$5E20_0000

$5E40_0000

$5E60_0000

$5E80_0000

$5EA0_0000

$5EC0_0000

$5EE0_0000

$5F00_0000

$5F20_0000

$5F40_0000

$5F60_0000

$5F80_0000
$5FA0_0000

$5FC0_0000

$5FFF_FFFF

USB

HRC/GS setting

Memory wait setting

BD

LSB setting

Write to LSB

DRAM transfer

SDRAM mode setting

Soft support function

FC control setting

Memory structure

setting

Timer

Engine
CDCC

Easy serial 1

16550

Switching clock

Default setting

$5FE0_0000

Mediation level setting

Interruption

External interruption

Figure 3.2 Memory map

III - 5

Figure 3.3 SIMM map

ADDRESS

0820 0000

123456789101112131415161718192021

NONE

1MB

1MB

1MB

2MB 2MB 2MB

1MB

1MB

2MB 2MB

1MB 1MB

2MB 2MB 2MB

1MB

1MB

2MB

4MB 4MB 4MB

4MB 4MB 4MB 4MB 4MB 4MB

8MB 8MB 8MB 8MB 8MB 8MB 8MB 8MB 8MB

8MB 8MB 8MB 8MB

1MB

2MB

4MB

1MB

1MB

2MB 2MB

4MB 4MB 4MB

1MB

2MB

1MB

2MB

4MB

1MB

2MB

4MB

8MB

0830 0000

0840 0000

0850 0000

0860 0000

0870 0000

0880 0000

0890 0000

08A0 0000

08B0 0000

08C0 0000

08D0 0000

08E0 0000

08F0 0000

0900 0000

0910 0000

0920 0000

0930 0000

0940 0000

0950 0000

0960 0000

0970 0000

0980 0000

0990 0000

09A0 0000

III - 6

Figure 3.4 Main PCB

ASIC M65243FP

CPU(VIDEO)

CPU(ENGINE)

ASIC µPD65626

ASIC M65340 FP

Control panel connector

Font card connector

Font cartridge connector

Centronics parallel I/F connector

ROM block

RS-232C serial I/F connector

DRAM block

SIMM block

Option I/F connector

III - 7

1.3 Engine Controller Circuit

A. Engine Control CPU
B. Low-Voltage Power Supply Connector
C. Fuser Unit Control

C-1. Heater Drive Circuit
C-2. Heater Temperature Input Signal

C-3. Paper Eject Input Signal
D. Paper Feeder PCB Control Signals and Connector
E. Option Interface Circuit and Connector
F. High-Voltage Power Supply Control Circuit and Connector
G. Scanner Unit Control

G-1. Scanner Motor Control Circuit

G-2. Laser Diode Drive PCB Control Circuit
H. Fan Motor Drive Circuit
I. Main Motor Control Circuit
J. Cover Open Detect Circuit
K. Safety Door Switch Circuit

Components in the Circuit (refer to the next page)

Engine

Controller

Circuit

Primary charging roller

MP Tray Pick-up Solenoid

Scanner Unit

High-Voltage
Power Supply

Assy

Paper Feeder

PCB

Detectors

Main Motor

Low-Voltage

Power Supply

Assy

Pick-up Motor

Fixing Unit

Transfer roller

Developing cylinder

Toner sensor

Pick-up Solenoid

Figure 3.5 Engine Controller Block Diagram

III - 8

2. PAPER FEED DRIVE CIRCUIT

A. Connector to Main PCB
B. Pick-up Motor Drive Circuit and Connector
C. Pick-up Solenoid Drive Circuit and Connector
D. Multi Purpose Tray Pick-up Solenoid Drive Circuit and Connector
E. Sensors

E-1. Tray1 Paper Empty Sensor
E-2. Multi Purpose Tray Paper Empty Sensor
E-3. Regist Sensor
E-4. Pre-Regist Sensor
E-5. Paper Detect Sensor in Duplex Unit

F. Tray1 Paper Size Detect Switches

Refer to the next page.

III - 9

Figure 3.7 Paper Feed/Size-SW PCB Circuit

B48K139-1

P5(ENGINE)

ABC

D

FE-MT

FE-MT

FE-MT

FE-MT

CA SOL

MP SOL

PF-PE

796820

19

3

±0V

±0V

±0V

±0V

±0V

MP-PE

REGIST

PREREG

DUPE

PH2

PH5

PH1

PH4

PH3

14

5

13

2

±0V

±0V

±0V

±0V

±0V

+5V

470

R2

E-1

+5V

E-2

+5V

E-3

+5V

E-4

+5V

E-5

470

470

470

470

R14

R1

R13

R9

P2(SIZE)

PSIZE1

PSIZE2

PSIZE3

PSIZE4

±0V 0V

243

1

5

171516

18

SIZE1

SIZE2

SIZE3

SIZE4

HOLD

+24VB

+24VRET

+5V

0V

HLD (* -05D)

+24VB

+24VRET

+5V

±0V

R16

4.7K

+24VRET

±0V

R15

4.7K

0V

Q3

2SC5060

+24V +24V

CA-SOL

P3 (CA SOL)

1

2

+24VRET

Q2

2SC5060

+24V +24V

MP-SOL

P4 (MP SOL)

1

2

(* -02D) HLD

Q1

DTC114ES

±0V

R12

82

R11

27

R10

1K

+5V

+24VRET

+24VRET+24VRET

R5

1-1W

R6

1-1W

R4

2.2K

R7

2.2K

C4

222

C5

222

C6

471

C3

471

R8

47K

R3

47K

+5V

0V

C2

103

C1

100µ-35V

+24VB

+24VB

+

+24VB

+24VB

4

3

MT D

6

MT C

1

MT B

2

MT A

5

P1(FEED MOTOR)

#1

SLA7027M

B48K140-1

P1(SIZE)

PSIZE1

PSIZE2

PSIZE3

PSIZE4

0V

4

3

2

1

5

SW1

SW2

SW3

SW4

±0V

INA

INB

INAN

INBN

TDA

TDB

OUTA

OUTB

OUTAN

OUTBN

VSSA

VSSB

RSA

RSB

GNDA

GNDB

REFA

REFB

6175162

13910

8181117

12314415

F

D

C

B

F

A

11410

12

1

III - 10

LCD

LED1

LED3
LED4

LED2

SW8 SW7 SW6 SW5 SW4 SW3 SW2 SW1

PAD4-PAD7

LED2 (READY)

LED3 (DATA)

LED4 (ALARM)

LCDE, LCDRS

LED1 (ONLINE)

SW8 (SEL)

SW7 (MODE)

SW6 (FONT)

SW5 (

FORM FEED

)

SW4 (SET)

SW3 (CONTINUE)

SW2 (DOWN)

SW1 (UP)

Main PCB

Figure 3.8 Display Circuit

3.2 Operation

Indicators on the control panel (LED lamps and LCD) are controlled by the video controller
circuit.

All the switch signals are input to the video controller circuit.
Signals Descriptions:
LED1 - LED4 On-off control for the respective LED lamps.

Illuminating when Low and extinguished when High.
PAD4 - PAD7 LCD control signal.
LCDRS A signal to distinguish PAD4 - PAD7 into command and data.
LCDE A signal to start the operation.
SW1 - SW8 Input signals from the switches.

Going Low when each switch is pressed.

3. DISPLAY CIRCUIT

3.1 Outline

The control panel of this printer has four LED lamps, one LCD display, and eight switches.
The control panel is connected to the Main PCB and its functions are as follows:
(1) The LCD shows the printer status and error message in alpha-numeric characters.
(2) The LED lamps indicate the operating conditions of the printer.
(3) The printing mode and LCD brightness can be changed by switches.

III - 11

4. LOW-VOLTAGE POWER SUPPLY ASSY

4.1 Outline

The low-voltage power supply assy consists of the low-voltage generating block (hereinafter the
DC block) and the heater drive circuit block to turn the heater on (hereinafter the AC block).

When the power switch (SW1) is turned on, AC power is supplied to the low-voltage power supply
assy.

The DC block generates +5 VDC, and +24 VDC.
When the heater is turned on, AC power is supplied to the AC block under control of the heater

on-off signal from the engine controller.
+24V output is reserved in the DC block, for the cooling fan for the low-voltage power supply

assy.

4.2 Protection Functions

Each of the power supply circuits, +5V, and +24V, has a protection function to prevent the circuit
from accident by automatically cutting off the power supply in the case of a over-voltage or over­current of the load.

When the cooling fan stops to rotating, an over-voltage protection or a short-circuit protection
function is activated, and all the DC power supplies are cutoff.

In this case check and clear the cause on the load after turning the power switch (SW1) off, and
then switch the power on again at least one minute after the power shut-down.

III - 12

Heater

Control

Thermal

Fuse

Lamp

H1TH1

AC IN

21

L

N

L

N

Power

Switch

(SW1)

Noise

Filter

Rectfier

Inlet

Transformer

Rectfier

Chopper

Over

Voltage

Detector

Feedback Control

1

4

2

3

6

7

5

8

HEAT/

+24V

+5V

+5V

±0V

±0V

+24VRET

FANLOCK/

P3

To Heater Circuit

F101

F102

P1

Figure 3.9 Low-Voltage Power Supply PCB Block Diagram

III - 13

5. HIGH-VOLTAGE POWER SUPPLY ASSY

5.1 Outline

The High-Voltage Power Supply Assy supplies the high-voltage for the charging roller, the
developer cylinder and the transfer roller according to the engine CPU’s control signals.

The block diagrams are shown Fig 3.10 and 3.11.

5.2 Operation of the Components of the High-Voltage Power Supply Assy

(1) Primary charging

When input signal/HV1AC gets the Low level, the primary high-voltage AC is applied to the
primary charging roller. And when input signal/HV1DC gets the Low level, the primary high­voltage DC is applied to the primary charging roller. The primary high-voltage DC changes with
developer bias DC according to values of the input signal DNSTY which is for print density
adjustment.

(2) Developer bias

When input signal/DBAC gets the Low level, the developer bias AC is applied to the developer
cylinder. And when input signal/DBDC gets the Low level, the developer bias DC is applied to
the developer cylinder. The developer bias DC changes according to values of the input signal
DNSTY which is for print density adjustment, like the primary high-voltage DC.

(3) Transfer charging

Transfer bias is controlled by the input signals HVT1 - 4 and HVTFB. When the input signal/
HVT1 gets the Low level, negative high-voltage is applied to the transfer roller. When the input
signal/HVT2 gets the Low level, positive high-voltage is applied to the transfer roller. When the
input signal/HVT3 gets the Low level, positive high-voltage about 1100 times that of the input
signal HVT4 is applied to the transfer roller. The input signal HVTFB has voltage about 1/1100
times the positive voltage generated on the transfer roller. Once the engine CPU is informed of
this voltage, the bias applied to the transfer roller can be known.

Note: The HVT2 signal generates high-voltage irrespective of the HVT4 signal.

(4) Toner sensing

Voltage levels of the input signals TONER1 and TONER2 allow the engine CPU to check if the
cartridge is set or not and if toner is empty. The TONER1 carries the voltage generated at the
toner sensor and the TONER2 carries the developing bias output value.

III - 14

Current
Buffer

Current
Buffer

Current
Buffer

Current
Buffer

Current
Buffer

Current
Buffer

Sin Wave
Generator

High-Voltage
Electrode

P1

Control Unit
(Feedback Circuit)

(ON / OFF Circuit)

Pulse
Generator

Control Unit

(DNSTY Control Circuit)
(ON / OFF Circuit)

(Feedback Circuit)

Pulse
Generator

Control Unit
(Feedback Circuit)

(ON / OFF Circuit)

Control Unit

(DNSTY Control Circuit)
(ON / OFF Circuit)

(Feedback Circuit)

PULSE

DEVELOPER BIAS DC

DEVELOPER BIAS AC

PULSE

PRIMARY HIGH-VOLTAGE DC

PRIMARY HIGH-VOLTAGE AC

1
5
2
3
4

/HV1AC

DNSTY

/HV1DC

/DBAC
/DBDC

P4

High-Voltage
Electrode

P2

DBOUT

Figure 3.10 High-Voltage Power Supply Block Diagram 1

III - 15

TRANSFER HIGH-VOLTAGE

TONER SENSE

DBOUT

P4

8
7

10

9

6
11
13
12
14
15
16

/HVT3
/HVT2

HVTFB

HVT4

/HVT1
TONER1
TONER2

0V

24VRET

+5V

+24V

Pulse
Generator

Current
Buffer

P5

High-Voltage
Electrode

Current
Buffer

Attenuator

Constant Current
Control Unit

(Feedback Circuit)
(ON / OFF Circuit)

Toner Sense
Control Unit

(HVT4 Control Circuit)

Current
Buffer

(Toner 1 Circuit)
(Toner 2 Circuit)

P3

Toner Sense
Electrode

Pulse
Generator

Constant Voltage
Control Unit

Figure 3.11 High-Voltage Power Supply Block Diagram 2

IV - 1

•

Tapping screws

S tight M3 : 7kgf

•

cm

B tight M3 x 6 : 5kgf

•

cm

M3 x 8 : 7kgf

•

cm

•

Stepped screws

M3 : 7kgf

•

cm

M4 : 10kgf

•

cm

Safety Precautions

(9) When connecting or disconnecting cable connectors, hold the connector bodies not the

cables. If the connector has a lock, always slide the connector lock to unlock it.

(10) After repairs, check not only the repaired portion but also that the connectors and other

related portions function properly before operation checks.

Notes

•

On the next page is a disassembly order flow which helps you access the object
component.

•

Unless otherwise specified, the disassembled parts or components should be
reassembled in the reverse order of removal.

To prevent the creation of secondary problems by mishandling, observe the following precau­tions during maintenance work.

(1)

Always turn off the power before replacing parts or units. When having access to the power

supply, be sure to unplug the power cord form the power outlet.
(2) Be careful not to lose screws, washers, or other parts removed for parts replacement.
(3) Be sure to apply grease to the teeth of gears.
(4)

When using soldering irons and other heat-generating tools, take care not to damage

the

resin parts such as wires, PCBs, and covers.
(5)

Before handling the PCBs, touch a metal portion of the equipment to discharge static

electricity, or the electronic parts may be damaged due to the electricity charged in your

body.
(6) When transporting PCBs, be sure to wrap them in conductive sheets such as aluminum

foil.
(7) Be sure to reinsert self-tapping screws correctly, if removed.
(8) Unless otherwise specified, tighten screws to the torque values listed below.

CHAPTER IV MECHANICAL SYSTEM

IV - 2

PRINNTER DISASSEMBLING PROCEDURE

PRINTER BODY

1

2

3

4

5

6

8

9

10

11

12

19

18

17

16

15

14

13

EP-ED CARTRIDGE
PAPER TRAY

TONER CARTRIDGE LID

SIDE COVER L

FONT COVER ASSY

UPPER COVER ASSY

REAR COVER ASSY

MIO LID

SIDE COVER R

DC FAN MOTOR
HOLDER

SIMM REPLACE LID MIO BOX

PCB HOLDER

MAIN PCB

CONTROL PANEL UNIT

BEAM

SCANNER UNIT

DUCT, CARTRIDGE GUIDE L

CARTRIDGE STOPPER ASSY

SCANNER HOLDER ASSY

FEED FLAT CABLE 20P

PAPER FEED CHASSIS UNIT

PAPER DELIVERY HOLDER SPRING

FIXING UNIT

TRANSFER UNIT

CARTRIDGE GUIDE R

GROUND LEAF SPRING

PANEL ARM L,R

HEAT INSULATION COVER

LV HARNESS 8P

DC GEAR HOLDER ASSY

PS SWITCH WIRE

REMOTE SWITCH

HIGH-VOLTAGE POWER SUPPLY PCB ASSY

LOW-VOLTAGE POWER SUPPLY PCB ASSY

CHASSIS

7

DC FAN MOTOR

CARTRIDGE LOCK SPRING L.R,
HOLD ROLLER

IV - 3

PRINTER BODY

1.1 Configuration

Figure 4.1

1.2 Toner Cartridge Lid

(1) Remove the supporter from the toner cartridge lid.
(2) Remove the toner cartridge lid from the upper cover.

Figure 4.2

1.3 Side Cover L

(1) Release the lock by pinching the lever on the left top surface ( A ) and remove the cover

by pulling it rearward ( B ).

Figure 4.3

Toner cartridge lid

Upper cover assy

Control panel unit

Side cover L

Paper tray

Rear cover assy

Cleaner brush

Hook lever

Side cover L

A

Open the toner
cartridge lid

Supporter

Upper cover assy

Toner cartridge lid

Side cover R

B

Font cover assy

IV - 4

B

1.5 Upper Cover Assy, Rear Cover Assy

1.5.1 Upper cover assy, rear cover assy

(1) Loosen the 4 screws on the rear (the upper 2 screws secure also the upper cover ).

1.4 Font Cover Assy

(1) Remove the font cover assy by loosening the screw on the top and releasing the hooks

on the bottom and the side.

Figure 4.6

Figure 4.4

A

Screw

Hook

Font cover assy

Hook

Upper cover assy

Screws

Screws

Rear cover assy

Figure 4.5

(2) Loosen the top left screw.
(3) Remove the upper cover assy ( A ) (Refer to Figure 4.5).
(4) Remove the rear cover by pulling it rearward ( B ) (Refer to Figure 4.5).

Screw

hook

Upper cover assy

Note: The hook is released automati cally

by removing the upper cover assy
in the direction of the arrow.

IV - 5

1.5.2 Changeover guide, jam remove cover

(1) Open the jam remove cover by hooking your finger on 2 dents ( A ).
(2) Remove the jam remove cover with its center part opened by bending the arm of the

boss both on sides ( B ) toward the front ( C ).

(3) Remove the changeover guide from the boss by bending the right hook (viewed from the

rear) of the rear cover ( D ), then remove the changeover guide ( E ).

1.6 Side Cover R

(1) Remove the side cover R by releasing the 4 hooks.

Figure 4.7

Hole

Rear cover assy

Changeover guide

Jam remove cover

Dents

Boss

D

E

B

C

A

Figure 4.8

Front

Side cover R

Hook at 4 places

Note: Before releasing the 4 hooks, remove

the paper tray.

Rear

IV - 6

1.7 DC Fan Motor 97-P031

(1) Remove the DC fan motor from the DC fan motor holder by loosening the two screws.
(2) Loosen the screws securing the PCB holder and remove the entire DC fan motor holder.
(3) Remove the fan harness connector from the main PCB assy.

Figure 4.10

Figure 4.11

1.8 Main PCB

Note: If replacing the main PCB with a new one, follow the step in the attached insertion

sheet with the new main PCB to install it.

(1) Remove the SIMM replace lid.

Figure 4.9

2 screws

DC fan holder

Screw

Fan connector

DC fan motor

Screws (yellow)

SIMM replace lid

MIO box

Screws

(2) Remove the MIO box.

IV - 7

(3) Remove the PCB holder by loosening PCB holder fixing screws, 2 centronics connector

screws and 2 RS-232C connector screws.

Figure 4.12

(4) Remove the switch flat cable 21P and the feed flat cable 20P.
(5) Remove the fan harness 3P, the fuser harness 4P, the SCN harness 4P, the SCN flat cable 6P,

the DC motor harness 4P, the HV harness 16P and the LV harness 8P.

Figure 4.14

Figure 4.13

PCB holder

Screws

SCN harness 4P

HV harness 16P

LV harness 8P

Switch flat cable 21P

Feed flat cable 20P

SCN flat cable 6P

Fuser harness 4P

7 screws

Main PCB assy

(6) Remove the main PCB assy.

Fan harness 3P

DC motor harness 4P

IV - 8

1.9 Control Panel Unit

Figure 4.17

READY

DATA

ALARM

ON LINE
SEL

MODE

FONT

FORM FEED

SET

CONTINUE

EMULATION

ECONOMY

FEEDER

COPY

SHIFT

RESET

TEST

COPY PAGES

FEEDER

ORIENTATION

DUPLEX

(4) Release the panel sheet 8 hooks to remove the panel sheet from the control panel.

Figure 4.16

Screws

Switch flat cable 21P

Pin

Panel arm L

Control panel unit

Control panel unit

Panel sheet

8 Hooks

C

Main PCB

(1) Remove the left side the control panel from the arm L by loosening the screws of the panel

arm L.
(2) Remove the switch flat cable 21P from the main PCB.
(3) Remove the control panel from the right panel arm R pin by sliding the control panel to the right.

Figure 4.15

D

A

B

A Tilt the control panel unit.
B Pinch the lever.
C While pinching the lever,

rotate, downward toward
you, the control panel unit on
the right pin taken as a fulcrum.

D Remove the control panel

unit.

IV - 9

1.10 Scanner Unit

(1)

Unplug the LD PCB harness (scanner flat cable) connector (6P), and SCN harness connector

(4P).
(2) Remove the beam from the body by loosening the screws.
(3) Remove the scanner unit from the body by loosening the screws.

Caution: Do not disassemble the scanner unit, it can be only adjusted at the factory.

Figure 4.20

Figure 4.19

1.11 Cartridge Stopper Assy

(1)

Loosen 4 screws and remove the scanner mount plate in the direction of the arrow (the

ground

leaf spring is also released at the same time.)

(2) Release the hook by bending the arm of the cartridge stopper assy ( A ), slide the cartridge

stopper assy to the left ( B ) and the remove the cartridge stopper assy ( C ).

Figure 4.18

SCN harness 4P
connector

Screws

Screws

Scanner unit

Ground leaf spring

Scanner mount plate

Screws

Cartridge stopper assy

Scanner mount plate

Cartridge stopper assy

C

B

A

Beam

Scanner flat cable 6P
connector

Right side

Left side

Rear

Front

IV - 10

1.12 Paper Feed Chassis Unit

(1) Pull out the unit by loosening the 8 screws (4 screws for front and 4 screws for bottom).

(2) Remove the paper hold front and paper hold rear by pinching the pawl of the paper hold front

with pliers.

Paper hold front

Screws

Screws

(3) Release the left cartridge hold roller and remove the cartridge guide L (by loosening the screw

and releasing the hook) then pull out feed flat cable 20P.

Screw

Figure 4.22

Note: When installing the paper feed chassis unit, screw the left chassis of this paper feed chassis unit,

set the paper tray, displace the right chassis of this unit up to the paper tray and screw them.

Hook (the rear side)

Cartridge hold roller

Pliers

Figure 4.21

Paper hold rear

Feed flat cable 20P

Screws

Screws

Paper feed chassis unit

Cartridge guide L

IV - 11

(4) Remove the paper feed chassis unit.

Figure 4.23

1.13 Separation Pad Assy

(1) Remove the paper pick-up roller assy and roller collar. (Refer to subsection 1.22)
(2) Remove the separation pad assy by pulling it out from the paper feed guide upper.

Figure 4.24

(3) Remove the spring from the separation pad assy.

Figure 4.25

Separation pad assy

Separation pad spring

Paper feed chassis unit

Paper feed guide upper

Paper pick-up roller assy

Paper pick-up roller collars

Separation pad assy

IV - 12

1.14 MP PE Sub Actuator

(1) Pull out the actuator upward from the MP tray assy (pay attention to the hook because it is fragile).

Figure 4.28

MP PE sub actuator

Figure 4.26

1.15 P Feed /Size-SW PCB Assy

(1) Put the 3 chassis L tabs to their original position.

Tabs

2 solenoid harness
connector

2 screws

Paper feed motor
harness connector

Figure 4.27

(2) Unplug the 2 solenoid connector and the paper feed motor harness connector.
(3) Loosen the 2 screws of the size-sw PCB.

Size-switch spring

Size-SW PCB

1.16 Side-Switch Spring

(1) Pull out the size-switch spring.

P feed/ size -SW PCB assy

IV - 13

1.17 Regist sensor actuator

(1) Remove the actuator by shifting it to the left from the chassis hole.

1.18 MP Paper Detection Actuator

(1) Remove the actuator by removing the 2 bearings from the roller holder.

This operation should be carried out with the PCB removed.

1.19 PE Sensor Actuator MP

(1) Pull out the actuator by shifting it to the right from the chassis hole.

Figure 4.30

Figure 4.31

Figure 4.29

MP paper detection actuator

Roller holder

MP paper detection actuator

PE sensor actuator MP

Regist sensor actuator

Regist sensor actuator

PE sensor actuator MP

IV - 14

1.20 Tray Sensor Holder

(1) Disengage the DU (Duplex) detection actuator from the hook and slide it to the outside.
(2) Loosen the screw and remove the holder by lifting it from the chassis.

PE sensor actuator tray, PE actuator link, DU detection actuator

1) Remove the PE actuator link from the PE sensor actuator tray.

2) Remove the PE actuator link from the tray sensor holder.

3) Remove the PE sensor actuator tray from the tray sensor holder.

4) Remove the DU detection actuator from the tray sensor holder.

Roller holder

Screws

Figure 4.32

1.21 Roller Holder

(1) Remove the gear 28.
(2) Loosen and pull out the 2 screws.

DU detection actuator

PE actuator link

Tray sensor holder

PE sensor actuator tray

Screw

Hook

Gear 28

Figure 4.33

IV - 15

1.22 Paper Pick-up Roller Assy, Bearing

(1) Pull out the MP paper pick-up gear 35 and the tray paper pick-up gear 35, from the paper pick-

up roller shafts.

(2) Loosen the bearing screws and pull out the paper pick-up rollers.

*When only the paper feed rollers are to be replaced, they can be replaced without removing
the paper feed unit (with the body assembled).

Paper pick-up roller shafts

Tray paper pick-up gear 35

MP paper pick-up gear 35

Bearing

Paper pick-up roller assy

Figure 4.34

Figure 4.35

Paper pick-up roller collars

Paper pick-up
roller assy

Bearing

Paper pick-up roller shafts

(3) Pull out the paper pick-up roller shafts.
(4) Remove the paper pick-up roller collars from the paper pick-up rollers assy.

Screws

Paper pick-up roller collars

Bearings

Paper pick-up roller assy

Paper pick-up roller
collars

Figure 4.36

IV - 16

Figure 4.39

1.23 Paper Pick-up Solenoid

(1) Remove each solenoid by loosening their screw.

1.24 Paper Feed Motor Assy

(1) Pull out the paper feed motor assy by loosening its 2 screws.

Figure 4.37

Paper pick-up solenoid

Screw

Paper pick-up solenoid

Screw

Screw

Screw

Paper feed motor assy

(2) For each assy, loosen a screw and pull out the bearing and the 6 washers.

See the picture below.

Figure 4.38

Paper feed roller assy 70s

Washer

Paper feed roller assy 60

Screws

Washer

Washer

Washer

Washer

Bearing

Screw

Bearings

Washer

IV - 17

1.25 MP Tray Cover

(1) Remove the MP tray cover from the paper feed chassis unit by bending its hook on both sides.

Figure 4.40

Figure 4.41

Figure 4.42

(2) Remove the MP extension tray from the MP tray cover by bending the former.

1.26 MP Tray Assy

(1) Remove the MP tray assy from the MP tray cover by bending its bosses.

Paper feed chassis unit

Hook

MP tray cover

MP extension tray

Hook

MP extension tray

MP tray cover

Boss

MP tray assy

Boss

MP tray cover

IV - 18

(2) Remove the 2 fixing bushes.
(3) Remove the MP tray assy.

(4) Remove the MP tray assy from the MP release plate bending its bosses.

The MP tray can be easily removed if it is slanted.

Figure 4.44

1.27 Paper Path Separation Plate, Paper Path Separation Film

(1) Remove them from the paper feed guide lower by bending them.

Paper feed guide lower

Paper path separation plate

Paper path separation film

Fixing bushes

MP tray assy

Figure 4.43

Figure 4.45

MP tray assy

Boss

MP release plate

Boss

IV - 19

1.28 Latch

(1) Remove the latch from the paper feed guide upper by releasing the 2 hooks.

Figure 4.46

1.29 Fixing unit (for both 120V and 230V, the only difference is the halogen heater)

(The fixing unit can be disassembled even after removing the rear cover in section 1.6).
(1) Release the hook of the heater lead wire connector (2P) by pinching the connector and pull it

out upward (to remove it from the low-voltage power supply assy).
(2) Pull out the fixing PCB connector (4P) to the rear ( A ).
(3) Loosen the 2 screws which are securing from the rear, and remove the fixing unit by pulling it

to the rear.

Figure 4.47

Paper feed guide upper

Hook

Hook

Latch

Heater lead wire

Fixing unit

Screw

Connector (2P)

Screw

Connector (4P)

A

IV - 20

,

,,,

,

,

,,

,,,,,

,,,,,

,

,,,

,,,

,

(4) Take off the halogen heater from the heater support spring, remove the halogen heater by

pushing it and pulling the heater support spring at the same time ( A ).

Figure 4.50

(6) Loosen a screw and remove the fixing PCB assy.

Figure 4.51

(5) Loosen 4 screws and remove the thermistor lead wire connector (2P) of the fixing PCB (see

Figure 4.51), and remove the fixing unit cover by detaching the wire from the hooks of the fixing
unit chassis.

Heater support spring

Halogen heater

Figure 4.48

Screws

Fixing unit cover

Fixing unit chassis

Hooks

Screws

Screw

Connector

A

A

Fixing PCB assy

Fixing unit

C

Halogen heater

B

A

Heater Push

A

Support spring Pull

Figure 4.49

IV - 21

(7) Release the left hook and take off the paper delivery actuator.

Figure 4.55

(8)

1) Remove the fixing heat insulation cover ( by loosening the 2 screws), the pressure roller
spring and pressure roller bearing on both sides, and the pressure roller.

Figure 4.53

2) Remove the retaining rings (on both sides).

3) Remove the HR gear, loosen the screw and remove the spring washer, remove the left and
right HR bearings and the heat roller by sliding it.

Figure 4.54

Screws

Heat insulation cover

Retaining ring

HR bearing

Screw

HR bearing

Heat roller

HR gear

Retaining ring

Spring washer

Pressure roller bearing

Pressure roller spring

Fixing unit chassis

Pressure roller

Paper delivery actuator

Fixing unit cover

Figure 4.52

IV - 22

1.30 Transfer Unit

(1) Loosen a screw.
(2) Release the 3 right hooks, (see Figure 4.57) lift the right part of the unit ( A ) and slide it to

the right ( B ) to take off the left part from the main chassis L. Remove the transfer unit from
the body by lifting the former.

(3) Open the transfer base hook and take off the left bearing (white) from the hook ( A ). Lift the

left side ( B ), slide it to the left ( C ) and take off the roller shaft from the right bearing (black) ( D ).

(4) Remove the transfer roller assy.

Caution : Do not touch the sponge rubber roller when replacing the transfer roller (the roller with

hand grease or clasped too strongly may result in poor printing quality).

Figure 4.57

Figure 4.56

Main chassis L

D

Transfer base assy

C

B

A

Transfer roller assy

3 Hooks

Screw

Transfer unit

Right

A

IV - 23

1.31 DC Gear Holder Assy

(1) Remove the DC motor connector, then remove the paper delivery holder spring.
(2) Loosen the 4 screws and remove the DC gear unit from the body.
(3) Remove the paper delivery gear assy, the gears, the gear 48 spring, and the washer.
(4) Loosen the 3 screws and remove the DC motor assy from the gear holder.

Figure 4.61

Figure 4.60

Figure 4.58

Figure 4.59

1.32 PS Switch Wire, Remote Switch

(1) Pull out the PS switch wire from the remote switch and the switch attachment.

Lift slightly the wires when pulling them out. This is in order to release the chassis caught at 2
places.

(2) Remove the remote switch from the chassis.

Paper delivery
holder spring

DC gear unit

PS switch wire

Remote switch

Gear 48

Gear 48 spring

Gear 24/72

Gear 20/50

Gear 39

3 screws

DC gear holder assy

Gear 22/55

Gear 28

Connector

DC motor assy

Gear 21

Paper delivery gear assy

Washer

Remote switch

Remote switch

Chassis

4 screws

Switch attachment

PS switch wire

IV - 24

1.33 High-Voltage Power Supply PCB

(1) Loosen the 2 screws.
(2) Hold the head of 4 resin spacers and lift this side of PCB ( A ).
(3) Slide the PCB to the opposite side ( B ).

(2) Remove the PS switch wire.
(3) Loosen the 2 screws on the side.
(4) Loosen the 4 screws on the top.

Figure 4.63

Figure 4.62

1.34 Low-Voltage Power Supply PCB Assy

(1) Be sure to remove the heat insulation cover before removing the low-voltage power supply block.

Figure 4.64

Resin spacers

Screws

The PCB can be detached without
removing this spacer

Resin spacers

Heat insulation cover

Heat insulation cover

Screw

Low-voltage power supply
PCB assy

PS switch wire

Screw

Screw

Screw

Screw

Hook

Hook

A

B

C

High-voltage power supply PCB assy

IV - 25

1.35 Toner Cartridge (EP-ED Cartridge)

(1) Remove the toner cartridge from the body.

Figure 4.65

1.36 Paper Tray

(1) Release the roller holder fixing pawl and remove the roller holder by pulling it out upward.
(2) Remove the roller.
(3) Remove the separation pad assy (pull it out by turning it) .

Figure 4.66

Separation pad assy and spring

Roller holder fixing pawl

Paper tray

Roller holder

Toner cartridge lid

EP-ED Cartridge

Roller

IV - 26

(4) Remove the tray gear holder from the other side by loosening the 3 screws and remove the gear

56T link.

Figure 4.67

Screws

Tray gear holder

Gear 56T link

V - 1

Table 5.1

No. Description Part No. Qty. Remarks

1

2

3

4

2

2

1

1

1Fixing unit UH2791001

(UH2601001)

(100,000) 120V

Fixing unit UH2792001

(UH2602001)

(100,000) 230V

Pick-up roller assy MP
Pick-up roller assy cassette

UH2362001 (100,000)
UH2362001

Separation pad MP
Separation pad cassette

UH2393001 (100,000)

Transfer roller assy

UH2788001

(100,000)

UH2393001

Service life

(number of print)

(UH2323001)

Note: The above table shows only estimated value, so these value are subject to change

without prior notice.

CHAPTER V MAINTENANCE AND SERVICING

1. PERIODICAL REPLACEMENT PARTS

Periodical replacement parts are the parts to be replaced periodically to maintain product
quality at same level (in other words the parts which would affect the product greatly if they lost
their function even if they are not damaged or there is no change in their appearance.)

It is recommended to replace such parts on the occasion of a periodical service which is
carried out before or after the specified number of sheets are used, whichever more
immediate to that time.

This machine contains no periodical replacement parts.

2. CONSUMABLE PARTS STANDARD ENDURANCE TABLE

The table below shows the suspected mean life (in terms of number of sheets) of the
consumable parts, that is the parts which subject to deterioration or damage, should be
replaced at least once during the period of warranty of the product only when the parts have
such a failure.

V - 2

3. LIST OF STANDARD TOOLS

The standard tool set required for servicing the printer is as listed below. These tools are
commercially available on the market.

Table 5.2

No. Description Remarks

1
3

4
5

Tool box

2 Lead cable

Feeler gauge
Compression spring scale (0 1kg)

Phillips screwdriver
6
8

9

10

Phillips screwdriver
7 Phillips screwdriver

Phillips screwdriver

Flat-blade screwdriver

Precision flat-blade screwdriver

11
13

14
15

Allen wrench set

12 File, fine

Allen (hex) screwdriver

Diagonal-cutting pliers

Needle-nose pliers

16
18

19
20

Pliers

17 Snap-ring pliers, ext. 19 30 mm

Crimper

Tweezers

Ruler

21
23

24
25

Mallet, plastic head

22 Brush

Penlight

Bottle, plastic

Solder

26
28

29
30

Desoldering wick

27 Oiler

Jar, plastic

Digital logic tester

Digital multimeter

31

33

Soldering iron

32 Digital memory scope or syncroscope

(100 MHz or over)

ROM remover

For checking cassette spring strength
M4, M5

M3, M5
M4, M5
M4, M5

M4

V - 3

4. LIST OF LUBRICANTS AND CLEANERS

No. Material name Components Use Remarks

Alcohol ethyl (pure
or denatured) or
isopropyl (pure or
denatured)

C

2H5

OH, (CH3)

2

CHOH

Cleaning of plastic,
rubber, and external
parts

•

Purchase locally

1

MEK (methyl ethyl
ketone)

CH

3

CO-C2H

5

Cleaning for oil and
toner stains

•

Purchase locally

•

Highly flammable; keep

away from flame

2

Lubricating oil
(silicon grease
KS64F)

For fuser

•

Tool No. ZX-43D

•

Equivalent oil may be

used

3

Lubricating oil
(Moly kote EM-30L)

For drive mechanism

•

Tool No. ZX-43N

•

Equivalent oil may be

used

4

Table 5.3

VI - 1

CHAPTER VI TROUBLESHOOTING

1. INTRODUCTION

1.1 Initial Check

(1) Operating environment

Check if:

1) The source voltage stays within ±10% from the rating voltage shown on the rating
label.

2) The printer is installed on a solid, level surface.

3) The room temperature is maintained between 10°C and 32.5°C. The relative humidity
is maintained between 20% and 80%.

4) The printer is not exposed to ammonia fumes or other harmful gases.

5) The printer is not located in a hot or humid area (such as near water or a humidifier), in
a cold place (such as outlet of an air conditioner), near open flames or in a dusty place.

6) The printer is not exposed to direct sunlight.

7) The room is well-ventilated.

(2) Printer paper

Check if:

1) A recommended type of print paper is being used (if the paper is too thick or too thin,
or tends to curl, paper jams or paper feed problems may occur, or prints may be
blurred).

2) The print paper is damped. [If so, use fresh paper, and check whether the print quality
improve or not.]

(3) Consumables

Check if:

1) The message "16 TONER EMPTY" is not shown on the status display when a
cartridge is installed in the printer . [If the message is displayed, replace the cartridge
with a new one. If blank spots occur on prints, take out the EP-ED cartridge and slowly
rock it to distribute the toner evenly.]

(4) Others

Check if:
The transfer guide and feed guide are clean. [If not, clean them with a damp cloth.]
Condensation:
When the printer is moved from a cold room into a warm room in cold weather,

condensation may occur inside the printer, causing various problems as below:

1) Condensation on the optical surfaces such as the scanning mirror, lenses, the reflection
mirror and the protection glass may cause the print image to be light.

2) If the photosensitive drum is cold, the electrical resistance of the photosensitive layer
gets high, making it impossible to obtain a correct contrast in printing.

3) Condensation on the pick-up guide and feed guide plates may cause paper feed
troubles.

If condensation has occurred, wipe the effected units or parts with a dry cloth.
If an EP-ED cartridge is unsealed soon after moved from a cold room to a warm room,

condensation may occur inside the cartridge, which may cause incorrect image. Instruct the user
to allow the cartridge to come to room temperature before unsealing it. This will take one to
two hours.

VI - 2

1.2 Basic Procedure

If a malfunction or incorrect print is appeared, make an initial check, then follow the basic
procedure below:

(1) Check the status display. If any message is shown, see Section 4 for troubleshooting.
(2)

If an incorrect image is found, see Section 3.1 to determine the defect type and Section

3.2 for image troubleshooting.

2. TEST PRINTING AND MECHANICAL CHECK

2.1 Test Printing

If an image problem occurs, follow the procedure below to produce a test print.

1) Enter the offline mode.

2) Press the SHIFT and TEST switches simultaneously, so the printer enters the test print
mode.

3)

Press the or switch to appear the message "TEST PRINT" then press the SET
switch.

The message "05 TEST PRINT" will appear on the status display of the control panel and

the

DATA lamp will come on. Then, the printer will produce the test print.

4) Determine the image trouble type and see Section 3 for troubleshooting.

TEST PRINT

Figure 6.1

VI - 3

3. IMAGE DEFECTS

3.1 Image Defect Examples

I-1 Light I-2 Dark I-3 Completely blank I-4 All black

I-6 Dirt on back of paper

I-7 Black vertical streaks I-8 Black and blurred

vertical stripes

I-10 Black and blurred
horizontal stripes

I-11 Dropout I-12 White vertical

streaks

I-13 Faulty

re

gistration

I-14 Poor fixing

I-5 Polka dots

I-9 Black and thin

horizontal streaks

Figure 6.2

VI - 4

3.2 Troubleshooting Image Defects

Yes

Possible cause Step Check Result Remedy

1

Yes

2

I-1

Yes3

Yes

Light

4

No

5

9

Yes

Toner shortage

Replace EP-ED cartridge.

Adjust the proper setting
on the control panel.

During a printing, open the toner cartridge lid
in the printer and pull out the EP-ED cartridge.

Go to the Step 9.

Paper failure

Does the print quality improve when fresh
paper is used?

Use recommended paper.

Does printed image improve when printed
density setting is changed on the control
panel ?

Printing
density setting

Does printed image improve when the EP-ED
cartridge is replaced?

Transfer input
signal error

Do the pins 7 and 8 of the connector P6
on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?

P6-7 pin (HVT2) --- Change in voltage from
15V approx. to 0V about 1 second after paper
feeding.

P6-8 pin (HVT3) --- Change in voltage from
9V approx. to 0V just when the voltage at the
7 pin changes from 0V to 15V.

Replace the main PCB assy
or the harness.

Dirt on power
supply terminal

Failure in the
transfer high­voltage circuit

Clean the transfer roller right end bearing, the
check continuity between the transfer roller
power supply spring and the terminal of the
high-voltage transfer unit. Is there continuity?

Clean the contact to assure
the continuity.

Replace the high-voltage
power supply assy.

Insufficient LD
light

Does print quality improve when the scanner
unit is improved?

Replace the scanner unit or
the harness.

Yes

-

7

8

6

No

ECONOMY
mode

Is the ECONOMY mode active?

Yes

Cancel the ECONOMY
mode.

Transfer roller
failure

Yes

Does the print quality improve when print is
made with transfer roller changed?

Clean the transfer roller [Use
dry lint-free paper (producing
little paper dust) to clean the
transfer roller. Never use
solvents] and, if dirts subsist,
replace the transfer roller assy.

Open the drum shutter of the EP-ED cartridge
and check the toner image on the drum.

Is the toner image before transfer is light?

Continued to the following page

VI - 5

10

No

Development
input signal error

Do the pins 3, 4 and 5 of the connector
P6 on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-3 pin (DBAC) --- Change in voltage from
6V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-4 pin (DBDC) --- Change in voltage from
9V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-5 pin (DNSTY) --- Change in voltage to

2.5V just when a sheet of paper is fed.

Replace the scanner unit or
the harness.

Possible cause Step Check Result Remedy

Dirt on power
supply terminal

Failure in the
development
high-voltage
circuit

Is there any dirt on the cartridge side
development terminal of the transfer unit and
on the terminal of the high-voltage power
supply development unit? (is there continuity
between them?)

11

No

Clean the contacts to assure
the continuity.

Yes

Replace the high-voltage
power supply PCB assy.

1

Yes

Density setting Does printed image improve when density

setting is changed on the control panel?

Adjust the proper setting on
the control panel.

I-2

Dark

Possible cause Step Check Result Remedy

EP-ED cartridge

Is there any dirt on the cartridge side charging
terminal of the transfer unit and on the terminal
of the high-voltage power supply charging unit?
(is there continuity between them?)

5

No

Clean the terminal to assure
the continuity.

Yes

Replace the high-voltage
power supply PCB assy.

2

Does printed image improve when the EP-ED
cartridge is replaced?

Yes

Replace the EP-ED cartridge.

Dirt on the
grounding
terminal

3

Does printed image improve when continuity
is improved by cleaning the EP-ED cartridge
grounding terminal and the printer unit
grounding terminal?

Yes

Clean the contacts to assure
the continuity.

Charging input
signal error

4

Do the pins 1, 2 and 5 of the connector P6
on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-1 pin (HV1AC) --- Change in voltage from
6V approx. to 0V just when a sheet of paper is fed.
P6-2 pin (HV1DC) --- Change in voltage from
9V approx. to 0V just when a sheet of paper is fed.
P6-5 pin (DNSTY) --- Change in voltage to

2.5V just when a sheet of paper is fed.

No

Replace the main PCB assy
or the harness.

Dirt on power
supply terminal

Failure in the
charging high­voltage circuit

VI - 6

1

Yes

EP-ED cartridge Does printed image improve when the EP-ED

cartridge is replaced?

Replace the EP-ED cartridge.

I-3

Completely blank

Possible cause Step Check Result Remedy

Development
input signal
error

2

Do the pins 3, 4 and 5 of the connector?
P6 on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-3 pin (DBAC) --- Change in voltage from
6V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-4 pin (DBDC) --- Change in voltage from
9V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-5 pin (DNSTY) --- Change in voltage to

2.5V just when a sheet of paper is fed.

No

Replace the main PCB assy
or the harness.

Failure in power
supply terminal

3

Is there any dirt on the cartridge side
development terminal of the transfer unit and
on the terminal of the high-voltage power
supply development unit? (is there continuity
between them?)

No

Clean the terminal to assure
the continuity.

LD failure
Failure in

development
high-voltage circuit

4

Does print quality improve when the scanner
unit is improved?

Replace the scanner unit or
the harness.

Replace the high-voltage
power supply PCB assy.

Yes

No

1

Yes

Beam detection
error

Is the printer hung up with the PRINT message
remaining on the display even after a printing
when only a copy is printed?

Replace the scanner unit or
the harness.

I-4

All black

Possible cause Step Check Result Remedy

EP-ED cartridge

2

Does printed image improve when the EP-ED
cartridge is replaced?

Yes

Replace the EP-ED cartridge.

Charging input
signal error

3

Do the pins 1 and 2 of the connector P6 on the
main PCB have the following value respectively
when a sheet of paper is fed from the MP tray?

No

Replace the main PCB assy
or the harness.

Dirt on power
supply terminal

Failure in the
charging high­voltage circuit

4

Is there any dirt on the cartridge side charging
t

erminal of the transfer unit and on the terminal

of
the high-voltage power supply charging unit?
(is there continuity between them?)

Clean the contact to assure
the continuity

No

P6-1 pin (HV1AC) --- Change in voltage from 6V
approx. to 0V just when a sheet of paper is fed.
P6-2 pin (HV1DC) --- Change in voltage from 9V
approx. to 0V just when a sheet of paper is fed.

LD failure

Yes

Replace the high-voltage
power supply PCB assy and,
if the problem is not resolved,
replace the scanner unit or
the harness.

VI - 7

1

Yes

Failure in static­charge eliminator

Is there any dirt on the static-charge eliminator?

Clean the static-charge
eliminator.

I-5

Polka dots

Possible cause Step Check Result Remedy

Dirt on the
transfer roller

2

Is there continuity between the static-charge
eliminator and the chassis?

Yes

Ensure the grounding of the
static-charge eliminator.

Static-charge
eliminator
grounding failure

3

Does print quality improve when the transfer
roller is replaced?

Yes

Clean the transfer roller [Use dry
lint-free paper (producing little
paper dust) to clean the transfer
roller. Never use solvents] and,
if the dirt remains, replace the
transfer roller assy.

1

Yes

Dirt on the
PF guide

Is there any dirt on the back of the paper feed
guide and the jam remove cover near the static­charge eliminator?

Clean the PF guide or the
jam remove cover.

I-6

Dirt on back of paper

Possible cause Step Check Result Remedy

Dirt on the
transfer roller

2

Open the toner cartridge lid in the printer, pull
out the EP-ED cartridge and remove the paper
in the printer. Is there already dirt on the back
of the sheet thus removed?

No

Go to Step 6.

-

3

Is there any dirt on the transfer roller?

Yes

Clean the transfer roller and,
if the dirt remains, replace
the transfer roller assy.

Transfer input
signal error

4

Does the voltage at the 6 pin (HVT1) of the
connector P6 on the main PCB change from
9V to 0V for about 0.8 seconds?

Yes

Replace the main PCB assy
or the harness.

5

No

Dirt on power
supply terminal

Clean the transfer roller right end bearing, the
check continuity between the transfer roller
power supply spring and the terminal of the
high-voltage transfer unit. Is there continuity?

Clean the contact to assure
the continuity.

Failure in the
transfer high­voltage circuit

Replace the high-voltage
power supply PCB assy.

No

Dirt the fixing
guide

Is there any dirt on the fixing unit inlet guide?

6

Clean the fixing unit inlet
guide.

Yes

Fixing roller
grounding failure

Are the upper and lower rollers of the fixing
unit securely connected to the chassis via the
diode?

7

Ensure the grounding. No
Replace the fixing unit.Yes

Fixing unit failure

VI - 8

1

Yes

EP-ED cartridge

During a printing, open the toner cartridge lid
in the printer and pull out the EP-ED cartridge.
Open the drum shutter of the EP-ED cartridge
and check the toner image on the drum.
Are there vertical stripes on the drum?

Replace the EP-ED cartridge.

I-8

Black vertical streaks or Blurred vertical line

Possible cause Step Check Result Remedy

Fixing unit
damaged

Replace the fixing unit.

No

I-7

Possible cause Step Check Result Remedy

Drum or charging
roller failure

1 Do stripes appears at 95 mm or 38 mm

interval?

Yes Replace the EP-ED cartridge.

Fixing unit
failure

2 Do stripes appears at 80 mm interval? Yes Replace the fixing unit.

Black and blurred horizontal stripesI-10

1

Beam detection
error

-

I-9

Black and thin horizontal streaks

Possible cause Step Check Result Remedy

-

Replace the scanner unit or
the harness and, if the problem
is not resolved, replace the
main PCB assy.

VI - 9

Possible cause Step Check Result Remedy

Paper failure 1 Is recommended paper used? No Use recommended paper.

Paper soaked 2 Is paper soaked? Yes Store the paper in packing

paper to keep it from soaking.

DropoutI-11

EP-ED cartridge 3 Does printed image improve when the EP-ED

cartridge is replaced?

Yes Replace the EP-ED cartridge.

Transfer roller
failure

4 Is there any dirt on the transfer roller or is it

deformed?

Yes Clean or replace the transfer

roller assy.

Transfer input
signal error

5

Do the pins 7 and 8 of the connector
P6 on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-7 pin (HVT2) --- Change in voltage from
15V approx. to 0V about 1 second after a
sheet of paper is fed.
P6-8 pin (HVT3) --- Change in voltage from
9V approx. to 0V when the voltage at the
pin 7 changes from 0V to 15V.

No Replace the main PCB assy

or the harness.

Dirt on power
supply terminal

6 No Clean the contact to assure

the continuity.

Failure in the
transfer high­voltage circuit

Clean the transfer roller right end bearing, the
check continuity between the transfer roller
power supply spring and the terminal of the
high-voltage transfer unit. Is there continuity?

Replace the high-voltage
power supply PCB assy.

Yes

Possible cause Step Check Result Remedy

Toner bias 1 Do white vertical stripes appear like a band? Yes

Rock the cartridge, set it
again in the printer and
check again the print quality.

Drum damage 2 Does print quality improve when the EP-ED

cartridge is replaced?

Yes Replace the EP-ED cartridge.

White vertical streaksI-12

Transfer roller
failure

3 Is the transfer roller damaged or deformed? Yes Replace the transfer roller

assy.

Dirt on the
reflecting
mirror

4 Is the problem solved when the scanner unit

is replaced?

Yes Clean the reflecting mirror

with a cleaning tip or replace
the scanner unit.

VI - 10

Possible cause Step Check Result Remedy

Top margin
setting error

1 Does self test printing have no problem? Yes

Check again the top margin
setting in the printing data.

Paper load in
the cassette

2 Is over-amount of paper than specified load

on the cassette?

Yes Reduce the paper load below

the specified limit.

Faulty registrationI-13

Paper failure 3 Does print quality improve when

recommended paper is used?

Yes Use recommended paper.

Paper failure 4 Is paper curled? Yes Use recommended fresh

paper without curl.

Improper Y
offset setting

5 Does print quality improve when Y offset

setting is changed?

Yes Ajust Y offset setting to an

appropriate value.

Jam remove
cover failure

6 Is the jam remove cover deformed? Yes Replace the jam remove

cover.

Failure in
regist sensor
actuator motion

7 Does the regist sensor actuator operate

smoothly?

No Reassemble the actuator

and, if the problem is not
resolved, replace the actuator.

Regist sensor
failure

8 Is the voltage at the pin 5 of the connector P3

of the main PCB 5V when no paper passes
and 0V when paper passes?

No Replace the paper feed/size-

sw PCB assy or the harness
and, if the problem remains,
replace the main PCB assy.

Paper feed
roller failure

Yes Replace the paper feed roller

assy.

Possible cause Step Check Result Remedy

Fixing unit release
spacer not
removed

1 Is the fixing unit release spacer removed? No

Remove the fixing unit
release spacer.

Paper failure 3 Is thick paper over than 36lb (135g/m2) used? Yes Instruct the user to use the

paper whose thickness is
less than the recommended
value.

Poor fixingI-14

Thermistor
failure

4 Is the voltage at the pin 3 of the connector

P11 of the main PCB is controlled within

1.80

±0.10V during continuous printing?

No Replace the fixing unit.

Replace the fixing unit.

Fixing unit
failure

Yes

2

MEDIA TYPE
setting

YesIs the MEDIA TYPE set to TRANSPARENCY?

Set the MEDIA TYPE to
REGULAR or THICK PAPER.

VI - 11

Malfunction of control panel LED lamps.M-3

Possible cause Step Check Result Remedy
LED lamps Dose the voltage of the following signals stay

0V while the "04 SELF TEST " is displayed
after switching the power on and stay 5V for
about 0.5 seconds after the message goes off?
(Do the LED lamps turn on and off in response
to the signal levels of 0V and 5V?)

1

Control panel
PCB

Switch flat cable

Main PCB Signal

LED1(ON LINE)
LED2(READY)
LED3(DATA)
LED4(ALARM)

Main PCB
P1-13
P1-7
P1-1
P1-6

Panel PCB
P1-9
P1-15
P1-21
P1-16

Yes

No

Replace the control panel
unit.

---

---

---

---

Replace the main PCB assy
or the switch flat cable.

4. TROUBLESHOOTING OF MALFUNCTIONS

Is the voltage of P4-8 in the low-voltage power
supply PCB connector 0V?

Possible cause Step Check Result Remedy

PCBs 1 Does any PCB have the short circuit between

+24V and 0V,+5V and 0V or +24V and +5V?

Yes Replace the PCB having the

short circuit.

Low-voltage
power supply
PCB

Main PCB
LV harness
DC fan motor

2

Yes

Replace the low-voltage power
supply PCB assy.

No

Replace the main PCB assy,
the LV harness or the DC fan
motor.

No DC power suppliedM-1

Possible cause Step Check Result Remedy

LCD module 1 Yes

No

Replace the main PCB assy,
the switch flat cable or the
control panel unit.

Malfunction of LCD display on the control panel.M-2

Dose the voltage of the following signals
vary to 5V or 0V when the LCD displays are
changed through switch operations?
(Check following signals using the digital
memory scope with the trigger function for
this check)

Control panel
PCB

Switch flat cable

Main PCB Signal

PAD4
PAD5
PAD6
PAD7
LCDRS
LCDE

Main PCB
P1-9
P1-5
P1-11
P1-4
P1-3
P1-2

Panel PCB
P1-13
P1-17
P1-11
P1-18
P1-19
P1-20

P2-4
P2-3
P2-2
P2-1
P2-7
P2-5

Replace the control panel
unit.

---

---

---

---

---

---

---

---

---

---

---

---

LCD
7
8
9
10
4
6

---

---

---

---

---

---

VI - 12

Does the upper cover hook press the actuator
of the interlock switch on the main PCB
correctly when upper cover is closed?

Possible cause Step Check Result Remedy

Upper cover 1 No

Replace the upper cover assy.

"12 COVER OPEN" is displayed even if the upper cover is closedM-6

Yes

Replace the main PCB assy.

Main PCB

Possible cause Step Check Result Remedy

1

Control panel
PCB

Switch flat cable

Main PCB

Yes

No

Replace the Main PCB assy.

Mis-operation Are the switchs operated according to the

operation manual?

Operate the switches
correctly following the
operation manual.

Switch

2

When a switch is pressed,does the voltage of
the following signals change from 5V to 0V?

Signal
SW8(SEL)
SW7(MODE/EMULATION)
SW6(FONT/ECONOMY)
SW5(FORM FEED/FEEDER)
SW4(SET/COPY)
SW3(CONTINUE/SHIFT)
SW2(DOWN/RESET)
SW1(UP/TEST)

Main PCB
P1-8
P1-10
P1-12
P1-14
P1-16
P1-18
P1-20
P1-21

---

---

---

---

Panel PCB
P1-14
P1-12
P1-10
P1-8
P1-6
P1-4
P1-2
P1-1

---

---

---

---

No

Replace the control panel
unit or the switch flat cable.

Malfunction of control panel switches.M-4

Is the "Buzzer on mode "selected according
to the operation manual?
(To alternate the buzzer on/off mode selection,
press the MODE switch and select the
"Advanced mode".)

Check the buzzer signal with a oscilloscope.
Is the pulse of 4KHz output?

Possible cause Step Check Result Remedy

Operational
error

1 No Set the buzzer on mode.

2

No

Replace the main PCB assy.

Malfunction of buzzerM-5

Yes

Replace the main PCB assy.

Main PCB
Buzzer

VI - 13

Is the paper feed mode set correctly?

Possible cause Step Check Result Remedy

Mis-operation 1 No Set paper feed mode

correctly.

2

No

Replace the feed flat cable.

" CHECK XX TRAY " is displayed even if a paper-loaded cassette is mountedM-7

Yes

Replace the main PCB assy.

Main PCB

Actuator Does the actuator for the paper empty sensor

operate smoothly?

Reassemble or replace the
actuator.

No

Paper empty
sensor
Feed flat cable

Does the voltage of P5-3 (or P5-14) in the
Paper feeder PCB connector rise from 0V to
5V when the paper empty sensor is covered?

3

No

Replace the paper feed/size­sw PCB assy or feed flat
cable .

Paper feed flat
cable

Does the voltage of P3-3 (or P3-14) in the main
PCB connector rise from 0V to 5V when the
paper empty sensor is covered?

(or even if a paper is set on MP tray) XX is MP/T1/T2

4

Yes

Possible cause Step Check Result Remedy

1No

2 Yes

3

Yes

4

No

M-8 "14 NO CARTRIDGE " is displayed

EP-ED cartridge

Is an EP-ED cartridge installed correctly? Install the EP-ED cartridge

correctly.
Clean the electrode of the

transfer unit.

Is the electrode of the transfer unit dirty?

Transfer unit
electrode

High-voltage
power supply
PCB

Is the voltage of P4-13 in the high-voltage
power supply PCB connector higher than that
of P4-11 over 2.5V?

Is the voltage of P6-13 in the main PCB
connector higher than that of P6-11 over 2.5V?

HV harness
Main PCB

Replace the high-voltage
power supply PCB assy.

Replace the HV harness.
Replace the main PCB assy.

VI - 14

Possible cause Step Check Result Remedy

EP-ED cartridge 1 Take the EP-ED cartridge out of the printer

and rock it to distribute the toner evenly.
When the cartridge is returned to the printer,

does the LCD show "00 READY"?

Yes The problem was caused by

toner onesided due to too
little toner remaining.
Prepare to replace the new
cartridge.

High-voltage
electrode

2 Are the developing bias or the toner sensor

electrode of the high-voltage power supply PCB
assy

dirty?

Yes Clean the electrode.

High-voltage
power supply
PCB

3 Is the voltage of P4-13 in high-voltage power

supply PCB connector higher than that of P4-11,
when the EP-ED cartridge which is full with toner
is installed?

Yes Replace the high-voltage

power supply PCB assy.

HV harness 4 Is the voltage of P6-13 in the main PCB

connector higher than that of P6-11?

Yes Replace the HV harness.

Replace the main PCB assy.

No

Main PCB

M-9 "16 TONER EMPTY " is displayed

Possible cause Step Check Result Remedy
Actuator 1

Does the actuator of the paper delivery sensor
or the registration sensor operate smoothly?

No Reassemble or replace the

paper delivery actuator and
regist sensor actuator.

Fuser harness
Feed flat cable

3 Does the voltage of P11-1 in the main PCB

connector rise from 0V to 5V when the eject
sensor is covered, or the voltage of P3-5 in
the main PCB connector rise from 0V to 5V?

No Replace the fuser harness

or the feed flat cable.
Replace the main PCB assy.

Yes

2 Does the voltage of P2-1 in the fixing PCB

connector rise from 0V to 5V when the eject
sensor is covered, or the voltage of P5-5 in
the paper feeder PCB connector rise from
0V to 5V when the registration sensor is
covered?

No

Replace the fixing PCB assy
or the paper feed/size-sw PCB
assy.

Paper delivery
sensor
Regist sensor

"13 JAM XXXXXX" is not displayed even if a paper jam has occured
(or is displayed even if a paper jam has not occurred) XXXXXX is TRAYS/INSIDE/REAR/DUPLEX.

M-10

VI - 15

Possible cause Step Check Result Remedy

Low-voltage power
supply PCB

LV harness
Main PCB

1 Is the voltage of P7-1 in the main PCB

connector +24V?

No

R

eplace the main PCB assy

l

ow-voltage power supply PCB

assy, or the LV harness.

DC motor harness
DC motor assy.

2 Does the voltage of P7-4 in the main PCB

connector drop from 5V to 0V after dropping
the voltage of P7-3 from 5V to 0V?

No Replace the main PCB assy.

"54 MOTOR MALF" is displayed (The main motor rotation disabled)M-11

Yes

Replace the DC motor harness
or the DC motor assy.

Possible cause Step Check Result Remedy

Mis-operation 1 Is the paper feed mode set correctly? No Set paper feed mode

correctly.

Main PCB 2 Does the voltage of P3-20 (or 19) in the main

PCB connector rise from 0V to 5V and is a
pulses having about 11ms period generated
at P3-6, 7, 8 ,9 pin?

No

Replace the main PCB assy.

No paper pick-up from cassette (or MP tray)M-12

Feed flat cable 3 Does the voltage of P5-20 (or 19) in the paper

feeder PCB. Connector rise from 0V to 5V
and is the pulses having about 11ms period
generated at P3-6, 7, 8 ,9 pin?

No Replace the feed flat cable.

Paper feeder
PCB

4 Does the voltage of P3-1 (or P4-1) in the

paper feeder PCB connector drop from
24V to 0V and is the chopping pulses
generated at P1-1, 2, 5 ,6 pin?

No Replace the Paper feed/size-

SW PCB assy.

Pick-up(or MP
Pick) solenoid

5 Does the pick-up (or MP Pick) solenoid

operate?

No Replace the pick-up (or MP

Pick) solenoid.

Paper feed motor

6 Does the pick-up motor rotate? No

Replace the paper feed motor assy.

VI - 16

Possible cause Step Check Result Remedy

Main PCB 1 When a test print is carried out, is the voltage

of the each pin in the main PCB connector
P6 turned on and off as the below list?

No

Replace the main PCB assy.

HV harness 2

Is the voltage of the each pin of the high-voltage
power supply PCB connector P4 turned on and
off?

No Replace the HV harness.

M-13

Yes Replace the high-voltage

power supply PCB assy.

"55 HIGH VOL MALF" is displayed (Faulty output from the H.V.P.S. ASSY)

High-voltage
power supply PCB

Pin No. Signal name Voltage

(reference

value)

Remarks

/HV1AC 0V

5.8V

/HV1DC 0V

8.6V

/DBAC 0V

6.3V

/DBDC 0V

8.6V
DNSTY 1.0 ~ 4.0V
/HVT1 0V

8.7V

/HVT2 0V

15.1V

/HVT3 0V

9.0V

HVT4 0.4 ~ 5.0V

HVTFB 0.4 ~ 4.0V

TONER1 0.0 ~ 3.5V

0V 0V
TONER2 2.0 ~ 4.5V

24VRET 0V
5V 5V
24V 24V

1

2

3

4

5
6

7

8

9

10

11

13

12

14
15
16

Default: 2.5V

VI - 17

Possible cause Step Check Result Remedy

Thermal fuse 1 Is the thermal fuse located in the fixing unit

conductive?

No Replace the fixing unit.

Thermistor 2 Remove the fixing unit from the printer and

measure the resistance between two pins of
the 2 pin connector on the fixing PCB. Is the
measured resistance within the range of

1.0 M 1.6M (normal temperature)?

No Replace the fixing unit.

"50 FUSER MALF" is displayedM-14

Fixing heat
roller

3 Is the fixing heat roller located in the fixing unit

conductive?

No Replace the fixing heat roller.

Low-voltage
power supply
PCB

4 When the power is switched on, does the

voltage at connector pin P4-1 on the main
PCB go from 5V to 0V?

Yes Replace the low-voltage

power supply PCB assy.

Main PCB 5 Make sure if:

The EP-ED cartridge is installed in the printer
correctly.
The upper cover of the printer is closed.
A paper-loaded cassette is mounted.

No Replace the main PCB assy.

Note: When the printer has detected a fixing unit malfunction, do not power on for about 15

minutes.
Even if the power is on, the printer will shut off the power supply to the fixing heat roller

to prevent the fixing the unit from overheating.

Replace the main PCB assy ,
the SCN harness 4P,SCN flat
cable 6P or the scanner unit.

Possible cause Step Check Result Remedy

Main PCB
Scanner harness

1 Is the problem remedied when the power off

and on again?

No

"51 LASER BD MALF" is displayedM-15

Replace the main PCB assy,
the SCN harness 4P, SCN flat
cable 6P or the scanner unit.

Possible cause Step Check Result Remedy

Main PCB
Scanner harness

1 Is the problem remedied when the power off

and on again?

No

"52 SCANNER MALF" is displayedM-16

Scanner unit

VI - 18

Since this is a temporary
problem, remove the paper
used when the error
occurred and continue to
print.

Possible cause Step Check Result Remedy

Main PCB 1 Does this problem frequently occur? No

"41 PRINT CHECK" is displayedM-17

Replace the main PCB assy.Yes

VI - 19

5. TROUBLESHOOTING PAPER TRANSPORT PROBLEMS

5.1 Paper Jams

The paper path is divided into following three blocks:

1) The paper pick-up block, (The LCD display "JAM TRAYS")

2) The separation and feed block, (The LCD display "JAM INSIDE")

3) The fixing and paper delivery block, (The LCD display "JAM REAR")
Therefore, remedies for paper jam problems are described.
Respectively for these three blocks.

Figure 6.3

3

2

1

VI - 20

Yes

Instruct the user not to load
more than the maximum
amount of paper.

Possible cause Step Check Result Remedy

Adjustment
lever

Is the position of the adjustment lever of the

cassette corresponding to the paper sheet size?
(spring pressure
switching lever)

1No

2

J-1a

Print paper Instruct the user to use

recommended type of paper.

Instruct the user to follow the
correct method.

No

Maximum
paper load on
the cassette

3

Is a recommended type of paper being used ?

Is the print paper deformed, curled or wavy ?

Yes

Replace the print paper.
Instruct the user how to
storage.

Does the amount of paper loaded on the

cassette exceed the specified maximum paper

load?

Paper pick-up block (Pick miss)

4

Yes

Replace the pick-up rollers.

Pick-up rollers

5

Are the pick-up rollers defomed or worn?

6

Separation pad

Yes

Is the separation pad deformed or worn, or

is it detached?

Replace the pad assy.

For solenoid activation, no feeder motor operation and no regist sensor activation, refer to the
item NO PAPER PICK-UP FROM THE CASSETTE in the column MALFUNCTIONS.

Possible cause Step Check Result Remedy

2No

3

4

Paper front guide

J-1b Paper pick-up block ( Oblique feed jam )

No

No

Is the paper front guide set in the correct
position?

Set the paper front guide.

Cassette-feeding
sheet guide.
Cassette rear,
side guide

MP-feeding
paper sheet

1No

Adjustment lever
(spring pressure
switching lever)

Is the position of the adjustment lever of the
cassette corresponding to the paper sheet size?

Instruct the user to follow the
correct method.

Are paper sheets set along the left wall?

Instruct the user to set paper
sheets correctly?

MP-feeding
paper sheet MP
sheet guide

Is the cassette rear side guide set correctly?

No

Is the MP sheet guide set correctly?

Instruct the user to set it
correctly?

Instruct the user to set it
correctly?

VI - 21

YesIs the static-charge eliminator dirty?

Possible cause Step Check Result Remedy

Static-charge
eliminator

1 Is a recommended type of paper being used? Instruct the user to use

recommended type of paper.

2

Clean the static-charge
eliminator.

Separation and feed block (Paper jam)J-2

No

Print Paper

No Replace the transfer base assy.

Possible cause Step Check Result Remedy

Fixing unit
entrance guide

1 Yes

2

J-3

Replace the fixing unit.

Clean the entrance guide.

Yes

3

Is the separation guide worn or deformed?

Is the paper sensor arm movement smooth?

Yes

Replace the fixing unit.

Fixing and paper delivery block (Paper jam)

4

No

Replace the jam remove cover
and the rear cover assy.

5

Is the entrance guide dirty?

Paper delivery
actuator

No

Replace the changeover
guide.

Is the changeover guide movement smooth?

Is the delivery roller movement smooth?
Are there dirts or flaws on the ribs of the jam

remove cover and rear cover?

Delivery rollers

Changeover
guide

No

Replace the rear cover assy.

Paper jam
remove cover

Rear cover

Separation
guide

Fixing unit

VI - 22

5.2 Incomplete Paper Feed

Yes

Clean the entrance guide.

Yes

Check the motion of the
paper-pick up block.

No

Replace the fixing unit.

Possible cause Step Check Result Remedy

1

No

2

F-2

Instruct the user in correct
print paper storage procedure
to be free from moisture.

Yes

3

Is the wrinkle problem solved if fresh paper is

used?

Is the paper already wrinkled or being

fed askew?

Wrinkles

4

Print paper

Is a recommended type of paper being used?

Instruct the user to use
recommended type of paper.

Paper pick-up
block

Fixing unit
entrance guide
Fixing unit

Is the entrance guide dirty?

Is the position of the adjustment lever of the

cassette corresponding to the paper sheet size?

Possible cause Step Check Result Remedy

Print paper 1 No Instruct the user to use

recommended type of paper.

Adjustment lever
(spring pressure
switching lever)

2

Yes

Replace the paper front guide.

No

Replace the separation pad.

Double feedingF -1

Is a recommended type of paper being used?

3

Is the paper front guide broken?

Paper front guide

Separation pad

No

Instruct the user to switch
adjustment lever position.

VI - 23

X X X X X X X X

1 2 3 4 5 6 7 8

(2) While pressing the switch, turn the power on.

The LCD will display: LINE TEST

(1) Mount the font cartridge, the flush memory card and the optional MIO board.

Note: Use a Hewlett Packard Company C2053A#C01 Word Perfect as font cartridge.

6. OPERATION

6.1 Line Inspection Mode Procedure

34567812

(7) Press the CONTINUE switch to check the 1st stage cassette.

TRAY 1 = A4 Appears when the cassette is set to A4 size.
TRAY 1 = LETTER Appears when the cassette is set to letter size.
TRAY 1 = NO Appears when no cassette is set.
CASSETTE ERROR!! Appears in case of error.

(8) Press the CONTINUE switch to check the 2nd stage cassette.

TRAY 2 = A4 Appears when the cassette is set to A4 size.
TRAY 2 = LETTER Appears when the cassette is set to letter size.
TRAY 2 = NO Appears when no cassette is set.
CASSETTE ERROR!! Appears in case of error.

(9) Press the CONTINUE switch to check multi purpose tray.

MP TRAY Set paper on the MP tray.
MP TRAY OK!!

(3) Press the SET switch to check if the LCD comes on.

All the LCD elements will come on
simultaneously.

(4) Press the CONTINUE switch to check the pushbutton switch.

All the LEDs will go out and the LCD will display the characters shown below:
Press all the switches by turns.

(6) Press the CONTINUE switch to check the fan.

FAN HIGH SPEED Make sure that the fan rotates at the high speed.
Press the CONTINUE switch.
FAN LOW SPEED Make sure that the fan rotates at the low speed.

(5) Press the CONTINUE switch to check RAM size.

RAM SIZE = 8MB 8M (standard)
RAM SIZE = XXMB XX : SIMM capacity + 2M
RAM SIZE ERROR In case of error

Switch key numbers

VI - 24

(10) Press the CONTINUE switch to check the font cartridge.

CART CHECK START

FONTCART OK!! The font cartridge is normal.

(11) Flash memory check

CARD CHECK START

FLASH OK!! The flash memory is normal.

(12) MIO check

MIO CHECK START

RAM SIZE = 2M

Now initializing

LJ WAIT 001P T1 You can turn off the power when this message is displayed. If there

is no toner cartridge or paper, the message "14 NO
CARTRIDGE"
will

be displayed.

LJ READY 001P T1

(13) Turn off the power.

Note:

The checks on and after (10) are carried out automatically, and if an error is

detected,
on of the following messages will be displayed. Checks can be resumed if the
CONTINUE switch is pressed.

FONTCART ERROR!! Font cartridge error (this message is displayed if a font cartridge

than a Hewlett Packard Company C2053A#C01 Word Perfect is
used.)

NO FONTCART!! No font cartridge is set.

FLASH ERROR!! Flash memory error

NO FLASH CARD!! No flash memory is set.

CHECK WP SWITCH The Write Protect switch of the flash memory is on.

45 MIO ERROR MIO error

NO MIO BOARD!! No MIO board is set.

Now initializing MIO error if this message remains displayed.