Canon LBP3250 Series User manual

Aug 13 2008
Service Manual
LBP3250 Series
LBP3250

Application
This manual has been issued by Canon Inc. for qualified persons to learn technical theory, installation, maintenance, and repair
of products. This manual covers all localities where the products are sold. For this reason, there may be information in this
manual that does not apply to your locality.
Corrections
This manual may contain technical inaccuracies or typographical errors due to improvements or changes in products. When
changes occur in applicable products or in the contents of this manual, Canon will release technical information as the need
arises. In the event of major changes in the contents of this manual over a long or short period, Canon will issue a new edition
of this manual.
The following paragraph does not apply to any countries where such provisions are inconsistent with local law.
Trademarks
The product names and company names used in this manual are the registered trademarks of the individual companies.
Copyright
This manual is copyrighted with all rights reserved. Under the copyright laws, this manual may not be copied, reproduced or
translated into another language, in whole or in part, without the written consent of Canon Inc.
COPYRIGHT © 2001 CANON INC.
Printed in Japan
Caution
Use of this manual should be strictly supervised to avoid disclosure of confidential information.

Introduction
Symbols Used
This documentation uses the following symbols to indicate special information:
Symbol Description
Indicates an item of a non-specific nature, possibly classified as Note, Caution, or Warning.
Indicates an item requiring care to avoid electric shocks.
Indicates an item requiring care to avoid combustion (fire).
Indicates an item prohibiting disassembly to avoid electric shocks or problems.
Indicates an item requiring disconnection of the power plug from the electric outlet.
Indicates an item intended to provide notes assisting the understanding of the topic in question.
Indicates an item of reference assisting the understanding of the topic in question.
Provides a description of a service mode.
Provides a description of the nature of an error indication.
Memo
REF.

Introduction
The following rules apply throughout this Service Manual:
1. Each chapter contains sections explaining the purpose of specific functions and the relationship between electrical and mechanical systems with refer-
ence to the timing of operation.
In the diagrams, represents the path of mechanical drive; where a signal name accompanies the symbol , the arrow indicates the
direction of the electric signal.
The expression "turn on the power" means flipping on the power switch, closing the front door, and closing the delivery unit door, which results in
supplying the machine with power.
2. In the digital circuits, '1'is used to indicate that the voltage level of a given signal is "High", while '0' is used to indicate "Low".(The voltage value, how-
ever, differs from circuit to circuit.) In addition, the asterisk (*) as in "DRMD*" indicates that the DRMD signal goes on when '0'.
In practically all cases, the internal mechanisms of a microprocessor cannot be checked in the field. Therefore, the operations of the microprocessors
used in the machines are not discussed: they are explained in terms of from sensors to the input of the DC controller PCB and from the output of the
DC controller PCB to the loads.
The descriptions in this Service Manual are subject to change without notice for product improvement or other purposes, and major changes will be com-
municated in the form of Service Information bulletins.
All service persons are expected to have a good understanding of the contents of this Service Manual and all relevant Service Information bulletins and be
able to identify and isolate faults in the machine."

Contents
Contents
Chapter 1 PRODUCT DESCRIPTION
1.1 Features .....................................................................................................................................................1- 1
1.1.1 Features ..................................................................................................................................................................1- 1
1.2 Product Specifications................................................................................................................................1- 2
1.2.1 Specifications ..........................................................................................................................................................1- 2
1.3 Name of Parts.............................................................................................................................................1- 3
1.3.1 External View...........................................................................................................................................................1- 3
1.3.2 Cross Section..........................................................................................................................................................1- 4
1.4 Using the Machine......................................................................................................................................1- 5
1.4.1 Control Panel...........................................................................................................................................................1- 5
1.5 Safety .........................................................................................................................................................1- 5
1.5.1 Safety of Laser Light................................................................................................................................................1- 5
1.5.2 CDRH Regulations..................................................................................................................................................1- 5
1.5.3 Safety of Toner........................................................................................................................................................1- 6
1.5.4 Handling the Laser Unit...........................................................................................................................................1- 6
1.5.5 Points to Note at Disassembly/Assembly Work.......................................................................................................1- 6
Chapter 2 TECHNICAL REFERENCE
2.1 Functional Configuration.............................................................................................................................2- 1
2.1.1 Outline.....................................................................................................................................................................2- 1
2.2 Basic Sequence..........................................................................................................................................2- 1
2.2.1 Basic Sequence of Operation..................................................................................................................................2- 1
2.2.2 Power-On Sequence...............................................................................................................................................2- 2
2.3 LASER EXPOSURE SYSTEM...................................................................................................................2- 3
2.3.1 Overview/Configuration...........................................................................................................................................2- 3
2.3.1.1 Overview..................................................................................................................................................................................2- 3
2.3.2 Controlling the Laser Activation Timing...................................................................................................................2- 4
2.3.2.1 Laser ON/OFF Control.............................................................................................................................................................2- 4
2.3.2.2 Horizontal Sync Control...........................................................................................................................................................2- 4
2.3.3 Laser Control...........................................................................................................................................................2- 5
2.3.3.1 Auto Power Control (APC).......................................................................................................................................................2- 5
2.3.4 Laser Scanner Motor Control ..................................................................................................................................2- 5
2.3.4.1 Overview..................................................................................................................................................................................2- 5
2.3.4.2 Scanner Motor Fault Detection ................................................................................................................................................ 2- 6
2.4 IMAGE FORMATION SYSTEM..................................................................................................................2- 7
2.4.1 Overview/Configuration...........................................................................................................................................2- 7
2.4.1.1 Overview..................................................................................................................................................................................2- 7
2.4.1.2 Print Process............................................................................................................................................................................ 2- 8
2.4.1.3 Static Latent Image Formation Block.......................................................................................................................................2- 9
2.4.1.4 Development Block................................................................................................................................................................2- 10
2.4.1.5 Transfer Block........................................................................................................................................................................2- 11
2.4.1.6 Fixing Block............................................................................................................................................................................2- 12
2.4.1.7 Drum Cleaning Block ............................................................................................................................................................. 2- 12
2.4.2 High-Voltage Control.............................................................................................................................................2- 13
2.4.2.1 Overview................................................................................................................................................................................2- 13
2.4.2.2 Generating Primary Charging Bias ........................................................................................................................................2- 13
2.4.2.3 Generating Developing Bias .................................................................................................................................................. 2- 13
2.4.2.4 Generating Transfer Bias.......................................................................................................................................................2- 13
2.4.3 Toner Cartridge .....................................................................................................................................................2- 14
2.4.3.1 Toner Level Detection............................................................................................................................................................2- 14
2.4.3.2 Toner Cartridge Absence/Presence Detection ......................................................................................................................2- 14

Contents
2.5 PICKUP AND FEEDING SYSTEM...........................................................................................................2- 15
2.5.1 Overview/Configuration..........................................................................................................................................2- 15
2.5.1.1 Overview................................................................................................................................................................................2- 15
2.5.2 Detecting Jams......................................................................................................................................................2- 16
2.5.2.1 Jam Detection Outline............................................................................................................................................................ 2- 16
2.5.2.2 Delay Jams ............................................................................................................................................................................2- 17
2.5.2.3 Stationary Jams ..................................................................................................................................................................... 2- 17
2.5.2.4 Other Jams ............................................................................................................................................................................ 2- 17
2.6 EXTERNAL AND CONTROLS SYSTEM.................................................................................................2- 18
2.6.1 Power Supply.........................................................................................................................................................2- 18
2.6.1.1 Power Supply.........................................................................................................................................................................2- 18
2.6.1.2 Protective Functions .............................................................................................................................................................. 2- 19
2.7 ENGINE CONTROL SYSTEM .................................................................................................................2- 20
2.7.1 Main Controller.......................................................................................................................................................2- 20
2.7.1.1 General description................................................................................................................................................................2- 20
2.7.2 Engine Controller...................................................................................................................................................2- 21
2.7.2.1 General description................................................................................................................................................................2- 21
2.8 FIXING UNIT/DELIVERY SYSTEM..........................................................................................................2- 22
2.8.1 Overview/Configuration..........................................................................................................................................2- 22
2.8.1.1 Overview................................................................................................................................................................................2- 22
2.8.1.2 Main Parts of Fixing Unit........................................................................................................................................................2- 22
2.8.2 Various Control Mechanisms.................................................................................................................................2- 23
2.8.2.1 Fixing Temperature Control ................................................................................................................................................... 2- 23
2.8.2.2 Protective Functions .............................................................................................................................................................. 2- 24
2.8.3 Other Functions .....................................................................................................................................................2- 25
2.8.3.1 Throughput Down Control......................................................................................................................................................2- 25
Chapter 3 DISASSEMBLY AND ASSEMBLY
3.1 EXTERNAL AND CONTROLS SYSTEM...................................................................................................3- 1
3.1.1 Rear Cover...............................................................................................................................................................3- 1
3.1.1.1 Before Removing the Rear Cover............................................................................................................................................ 3- 1
3.1.1.2 Removing the Rear Cover .......................................................................................................................................................3- 1
3.1.2 Right Cover..............................................................................................................................................................3- 1
3.1.2.1 Before Removing the Right Cover...........................................................................................................................................3- 1
3.1.2.2 Removing the Right Cover.......................................................................................................................................................3- 1
3.1.3 Left Cover ................................................................................................................................................................3- 1
3.1.3.1 Before Removing the Left Cover..............................................................................................................................................3- 1
3.1.3.2 Removing the Left Cover.........................................................................................................................................................3- 1
3.1.4 Upper Cover.............................................................................................................................................................3- 2
3.1.4.1 Removing the Upper Cover .....................................................................................................................................................3- 2
3.1.5 Front Cover..............................................................................................................................................................3- 3
3.1.5.1 Before Removing the Front Cover...........................................................................................................................................3- 3
3.1.5.2 Removing the Front Cover.......................................................................................................................................................3- 3
3.1.6 Delivery Tray............................................................................................................................................................3- 3
3.1.6.1 Removing the Delivery Auxiliary Tray...................................................................................................................................... 3- 3
3.1.7 Pickup Tray..............................................................................................................................................................3- 3
3.1.7.1 Before Removing the Pickup Tray ........................................................................................................................................... 3- 3
3.1.7.2 Removing the Pickup Tray Unit ............................................................................................................................................... 3- 3
3.1.8 Drive Unit.................................................................................................................................................................3- 4
3.1.8.1 Before Removing the Drive Belt...............................................................................................................................................3- 4
3.1.8.2 Removing the Drive Belt..........................................................................................................................................................3- 4
3.1.9 Main Drive Unit ........................................................................................................................................................3- 5
3.1.9.1 Before Removing the Main Motor ............................................................................................................................................ 3- 5
3.1.9.2 Removing the Main Motor........................................................................................................................................................3- 5
3.1.10 Engine controller board..........................................................................................................................................3- 7
3.1.10.1 Before Removing the Engine Controller PCB........................................................................................................................ 3- 7
3.1.10.2 Removing the Engine Controller PCB....................................................................................................................................3- 7
3.1.11 Main Controller PCB ..............................................................................................................................................3- 8

Contents
3.1.11.1 Before Removing the Main Controller PCB............................................................................................................................3- 8
3.1.11.2 Removing the Main Controller PCB....................................................................................................................................... 3- 8
3.1.12 Top sensor.............................................................................................................................................................3- 8
3.1.12.1 Before Removing the Paper Lead Edge Sensor....................................................................................................................3- 8
3.1.12.2 Removing the Paper Lead Edge Sensor................................................................................................................................ 3- 8
3.1.13 Sensor Boade........................................................................................................................................................3- 9
3.1.13.1 Before Removing the Sensor PCB.........................................................................................................................................3- 9
3.1.13.2 Removing the Sensor PCB.................................................................................................................................................... 3- 9
3.2 LASER EXPOSURE SYSTEM.................................................................................................................3- 10
3.2.1 Laser Scanner Unit................................................................................................................................................3- 10
3.2.1.1 Before Removing the Laser Scanner Unit ............................................................................................................................. 3- 10
3.2.1.2 Removing the Laser Scanner Unit.........................................................................................................................................3- 10
3.3 IMAGE FORMATION SYSTEM................................................................................................................3- 11
3.3.1 Transfer Charging Roller.......................................................................................................................................3- 11
3.3.1.1 Removing the Transfer Roller................................................................................................................................................ 3- 11
3.3.2 Memory Tag Contact Unit......................................................................................................................................3- 12
3.3.2.1 Before Removing the Memory Contact Unit ..........................................................................................................................3- 12
3.3.2.2 Removing the Memory Contact Unit......................................................................................................................................3- 12
3.4 PICKUP AND FEEDING SYSTEM...........................................................................................................3- 14
3.4.1 Pickup Unit ............................................................................................................................................................3- 14
3.4.1.1 Before Removing the Pickup Unit..........................................................................................................................................3- 14
3.4.1.2 Removing the Pickup Unit......................................................................................................................................................3- 14
3.4.2 Cassette Pickup Roller..........................................................................................................................................3- 15
3.4.2.1 Removing the Pickup Roller...................................................................................................................................................3- 15
3.4.3 Cassette Pickup solenoid......................................................................................................................................3- 15
3.4.3.1 Before Removing the Pickup Solenoid ..................................................................................................................................3- 15
3.4.3.2 Removing the Pickup Solenoid.............................................................................................................................................. 3- 16
3.4.4 Cassette Separation Pad.......................................................................................................................................3- 16
3.4.4.1 Removing the Separation Pad...............................................................................................................................................3- 16
3.5 FIXING SYSTEM......................................................................................................................................3- 16
3.5.1 Fixing Unit..............................................................................................................................................................3- 16
3.5.1.1 Before Removing the Fixing Unit........................................................................................................................................... 3- 16
3.5.1.2 Removing the Fixing Unit.......................................................................................................................................................3- 16
3.5.2 Fixing Film Unit......................................................................................................................................................3- 17
3.5.2.1 Before Removing the Fixing Film Unit ................................................................................................................................... 3- 17
3.5.2.2 Removing the Fixing Film Unit...............................................................................................................................................3- 17
3.5.3 Fixing Pressure Roller...........................................................................................................................................3- 18
3.5.3.1 Before Removing the Fixing Pressure Roller......................................................................................................................... 3- 18
3.5.3.2 Removing the Fixing Pressure Roller .................................................................................................................................... 3- 18
Chapter 4 MAINTENANCE AND INSPECTION
4.1 Periodically Replaced Parts........................................................................................................................4- 1
4.1.1 Periodically Replaced Parts.....................................................................................................................................4- 1
4.2 Consumables..............................................................................................................................................4- 1
4.2.1 Consumables...........................................................................................................................................................4- 1
4.3 Periodical Service.......................................................................................................................................4- 1
4.3.1 Scheduled Servicing................................................................................................................................................4- 1
4.4 Cleaning .....................................................................................................................................................4- 2
4.4.1 Cleaning Method .....................................................................................................................................................4- 2
Chapter 5 TROUBLESHOOTING
5.1 MEASUREMENT AND ADJUSTMENT......................................................................................................5- 1
5.1.1 Test Print.................................................................................................................................................................5- 1
5.1.1.1 Test Print Function...................................................................................................................................................................5- 1
5.1.2 Mechanical Adjustment ...........................................................................................................................................5- 1
5.1.2.1 Checking the Pressure of the Pressure Roller (nip)................................................................................................................. 5- 1

Contents
5.2 SERVICE TOOLS ......................................................................................................................................5- 2
5.2.1 Standard tools..........................................................................................................................................................5- 2
5.2.2 Special Tool.............................................................................................................................................................5- 2
5.2.3 List of solvent/ lubricant ...........................................................................................................................................5- 2
5.3 ERROR CODE TABLE...............................................................................................................................5- 3
5.3.1 Overview..................................................................................................................................................................5- 3
5.3.2 Service Message .....................................................................................................................................................5- 4
5.4 Version Up..................................................................................................................................................5- 4
5.4.1 Upgrade...................................................................................................................................................................5- 4
Chapter 6 APPENDIX
6.1 OUTLINE OF ELECTRICAL COMPONENTS............................................................................................6- 1
6.1.1 Clutch/Solenoid........................................................................................................................................................6- 1
6.1.1.1 Solenoid................................................................................................................................................................................... 6- 1
6.1.2 Motor........................................................................................................................................................................6- 1
6.1.2.1 Motor........................................................................................................................................................................................6- 1
6.1.3 Sensor......................................................................................................................................................................6- 2
6.1.3.1 Sensor......................................................................................................................................................................................6- 2
6.1.4 Switch ......................................................................................................................................................................6- 2
6.1.4.1 Switch ...................................................................................................................................................................................... 6- 2
6.1.5 PCBs........................................................................................................................................................................6- 3
6.1.5.1 PCB..........................................................................................................................................................................................6- 3

Chapter 1 PRODUCT DESCRIPTION

Contents
Contents
1.1 Features..........................................................................................................................................................................1-1
1.1.1 Features........................................................................................................................................................................................ 1-1
1.2 Product Specifications....................................................................................................................................................1-2
1.2.1 Specifications............................................................................................................................................................................... 1-2
1.3 Name of Parts.................................................................................................................................................................1-3
1.3.1 External View .............................................................................................................................................................................. 1-3
1.3.2 Cross Section ............................................................................................................................................................................... 1-4
1.4 Using the Machine.........................................................................................................................................................1-5
1.4.1 Control Panel ............................................................................................................................................................................... 1-5
1.5 Safety .............................................................................................................................................................................1-5
1.5.1 Safety of Laser Light ................................................................................................................................................................... 1-5
1.5.2 CDRH Regulations ...................................................................................................................................................................... 1-5
1.5.3 Safety of Toner ............................................................................................................................................................................ 1-6
1.5.4 Handling the Laser Unit............................................................................................................................................................... 1-6
1.5.5 Points to Note at Disassembly/Assembly Work .......................................................................................................................... 1-6

Chapter 1
1-1
1.1 Features
1.1.1 Features
0019-9494
1. Small-size, high-speed monochrome printer
This equipment has a compact body that realizes high-speed print of 23 ppm.
2. Reduction in standby time and energy consumption
This equipment employs on-demand fixing where the heater activates only during printing, resulting in a reduction in standby time and energy consumption on this
mode.
3. Realization of noise reduction and stable image quality
This equipment employs a belt drive method for transmitting the drive of the main motor. This enables lower noise and more stable image quality compared to the
conventional gear drive method. (See MEMO)
4.Improved Usability
In this equipment, the power switch is situated at the front of the host machine, and maintenance (jam removal, replacing the cartridge) can be performed by ac-
cessing one point of the delivery tray.
MEMO:
Changing the drive method from gear to belt reduces uneven pitch due to varied rotation speed of the photosensitive drum, which realizes stable image quality.

Chapter 1
1-2
1.2 Product Specifications
1.2.1 Specifications
0019-9496
Body installation method desktop page printer
Photosensitive medium OPC drum
Exposure method semiconductor laser
Development method Toner projection development
Transfer method by roller
Separation method Curvature
Pickup-tray pickup method by pad
Multifeeder pickup method by pad
Drum cleaning method by blade
Fixing method on-demand
Delivery method face-down
Toner supply type By toner cartridge
Warm-up time in standby: 0 sec (at power-on: 10 sec or less)
Print area top: 5 mm; bottom: 5 mm; left/right: 5 mm (if envelope, top, bottom, left,
right: 10 mm)
Printing resolution 600dpi
First print time approx. 6 sec or less (A4)
Print speed (A4) approx. 23ppm
Pickup-tray paper size A4, B5, A5, LGL, LTR, Executive,16K, Envelope(DL,COM10,C5,
Monarch), user-defined paper (76.2 to 215.9 mm in width, 127 to 355.6
mm in length)
Multi-purpose paper size A4, B5, A5, LGL, LTR, Executive,16K, Envelope(DL,COM10,C5,
Monarch), user-defined paper (76.2 to 215.9 mm in width, 127 to 355.6
mm in length)
Pickup-tray paper type plain paper (60 to 105 g/m2), heavy paper (106 to 163 g/m2),
transparency, label sheet, postcard
Pickup-tray paper capacity Approx. 250 sheets (plain paper 64 g/m2)
Multi-purpose capacity 1 sheet (plain paper 64 g/m2)
Delivery tray stack Approx. 100 sheets (plain paper 64 g/m2)
Duplex method None
Hard disk Standard: none, Option: none
Interface USB 2.0, Option: none
Memory Standard: 2MB, Option: none
Operating environment
(Temperature range) 7.5 deg C to 32.5 deg C
Operating environment
(Humidity range) 10 to 80%RH
Noise 55 dB or less (during printing; based on ISO9296; announced noise
emission)
Power supply rating AC120-127V, +/-10% (50,60Hz +/-2Hz)
AC220-240V, +/-10% (50,60Hz +/-2Hz)
Power consumption (Maximum) AC120-127V:
Approx.830W more less (The value of the reference room temperature at
20 deg C)
AC220-240V:
Approx.990W more less (The value of the reference room temperature at
20 deg C)
Dimensions 384 (W) x 258 (D) x 227 (H) mm
Weight Printer: Approx. 6.4kg, Toner cartridge: Approx. 0.6kg

Chapter 1
1-3
1.3 Name of Parts
1.3.1 External View
0019-9497
F-1-1
[1] Power switch [2] Delivery auxiliary tray
[3] Delivery tray [4] Manual feed tray paper guide
[5] Manual feed tray [6] Tray cover
[7] Pickup tray [8] Rear paper guide
[9] Pickup tray Paper guide [10] USB cover
[11] USB connector [12] Power receptacle
[9]
[8]
[1] [2]
[7] [6] [5] [4]
[11]
[12]
[10]
[3]

Chapter 1
1-4
1.3.2 Cross Section
0019-9498
F-1-2
[1] Fixing unit [2] Pressure roller
[3] Fixing sleeve unit [4] Delivery roller
[5] Laser scanner unit [6] Manual feed tray
[7] Pickup tray [8] Photosensitive drum
[9] Pickup roller [10] separation pad
[11] Feed roller [12] Transfer roller
[13] Toner cartridge
[1] [2] [3] [4] [5]
[6]
[7][8][9]
[11][12][13] [10]

Chapter 1
1-5
1.4 Using the Machine
1.4.1 Control Panel
0019-9499
F-1-3
[1] Power lamp (green)
Lighting:
Indicates that the power of the host machine is turned on.
Not lighting:
Indicates that the power of the host machine is not turned on.
[2] Paper lamp/paper key (red)
<Lamp>
Flashing:
Indicates that there is no paper in the pickup source and print cannot be executed, or papers cannot be fed correctly.
Not lighting:
Indicates that the machine can make prints.
<Key>
Pressing this key after executing pickup of paper or jam removal restarts printing.
1.5 Safety
1.5.1 Safety of Laser Light
0019-9500
Laser light can be extremely hazardous to the human body.
The machines laser scanning system is contained in a protective housing and external covers to prevent escape of laser light outside the machine. In other words,
the user is free of laser-related hazards as long as the machine is being used for its intended purposes.
The following warnings are given to comply with Safety Principles (EN60950).
Laserstrahlen können für den menschlichen Körper gefährlich sein. Aus diesem Grund ist das optische Lasersystem mit einem Schutzgehäuse und einer Außenab-
deckung dicht verschlossen und hat eine Struktur, die keine Laserstrahlen nach außen dringen lässt. Unter der Voraussetzung, dass der Benutzer dieses Gerät normal
bedient, ist ein Austritt von Laserstrahlen daher ausgeschlossen.
1.5.2 CDRH Regulations
0019-9501
The Center for Devices and Radiological Health of the US Food and Drug Administration put into effect regulations concerning laser products on August 2, 1976.
These regulations apply to products produced on and after August 1, 1976, and prohibit the sale of laser products without certification. The following is a label used
to certify compliance with the CDRH regulations, and all laser products to be sold in the US must bear this label.
F-1-4
[1]
[2]

Chapter 1
1-6
1.5.3 Safety of Toner
0019-9502
The machines toner is a non-toxic material made up of plastic, iron, and small amounts of dye.
Toner on Clothing or Skin
1. Remove toner from clothing or skin, and wash with water.
2. Do not use warm or hot water, which will cause the toner to turn jelly-like and fuse permanently with the fibers of clothing.
3. Toner tends to react readily with vinyl. Do not bring it in contact.
4. Storage of copy/print output
Do not use the polyvinyl case.
If printed side contacts with the surface of case, toner melts and the paper may be adhered with a case.
1.5.4 Handling the Laser Unit
0019-9503
The laser scanner unit emits invisible laser beam. DO NOT disassemble the unit as the laser beam can possibly damage your eyes. The unit cannot be adjusted in
the field. The following label is attached to the cover of the unit:
F-1-5
1.5.5 Points to Note at Disassembly/Assembly Work
0019-9505
Be sure to ensure the following notes when performing disassembly/assembly work.
1. Be sure to disconnect the power plug for safety when performing disassembly/assembly work.
2. As for assembly procedure, perform the reverse procedure of disassembly unless otherwise instructed.
3. Avoid making mistakes in the type of screws (length/diameter) and usage locations for assembly.
4. Screws w/washer are used as mounting screws for grounding wires and varistors with the aim of checking electric continuity. Be sure to use this screw for as-
sembly.
5. Basically, do not activate the machine with their parts being removed.
6. Do not remove paintlock screws at the time of disassembly.
Do not throw toner into fire. Doing so can lead to explosion.

Chapter 2 TECHNICAL REFERENCE

Contents
Contents
2.1 Functional Configuration...............................................................................................................................................2-1
2.1.1 Outline.......................................................................................................................................................................................... 2-1
2.2 Basic Sequence ..............................................................................................................................................................2-1
2.2.1 Basic Sequence of Operation....................................................................................................................................................... 2-1
2.2.2 Power-On Sequence..................................................................................................................................................................... 2-2
2.3 LASER EXPOSURE SYSTEM.....................................................................................................................................2-3
2.3.1 Overview/Configuration .............................................................................................................................................................. 2-3
2.3.1.1 Overview.........................................................................................................................................................................................................2-3
2.3.2 Controlling the Laser Activation Timing..................................................................................................................................... 2-4
2.3.2.1 Laser ON/OFF Control ...................................................................................................................................................................................2-4
2.3.2.2 Horizontal Sync Control .................................................................................................................................................................................2-4
2.3.3 Laser Control ............................................................................................................................................................................... 2-5
2.3.3.1 Auto Power Control (APC).............................................................................................................................................................................2-5
2.3.4 Laser Scanner Motor Control....................................................................................................................................................... 2-5
2.3.4.1 Overview.........................................................................................................................................................................................................2-5
2.3.4.2 Scanner Motor Fault Detection .......................................................................................................................................................................2-6
2.4 IMAGE FORMATION SYSTEM.................................................................................................................................2-7
2.4.1 Overview/Configuration .............................................................................................................................................................. 2-7
2.4.1.1 Overview.........................................................................................................................................................................................................2-7
2.4.1.2 Print Process....................................................................................................................................................................................................2-8
2.4.1.3 Static Latent Image Formation Block .............................................................................................................................................................2-9
2.4.1.4 Development Block.......................................................................................................................................................................................2-10
2.4.1.5 Transfer Block...............................................................................................................................................................................................2-11
2.4.1.6 Fixing Block..................................................................................................................................................................................................2-12
2.4.1.7 Drum Cleaning Block ...................................................................................................................................................................................2-12
2.4.2 High-Voltage Control ................................................................................................................................................................ 2-13
2.4.2.1 Overview.......................................................................................................................................................................................................2-13
2.4.2.2 Generating Primary Charging Bias...............................................................................................................................................................2-13
2.4.2.3 Generating Developing Bias .........................................................................................................................................................................2-13
2.4.2.4 Generating Transfer Bias ..............................................................................................................................................................................2-13
2.4.3 Toner Cartridge.......................................................................................................................................................................... 2-14
2.4.3.1 Toner Level Detection...................................................................................................................................................................................2-14
2.4.3.2 Toner Cartridge Absence/Presence Detection ..............................................................................................................................................2-14
2.5 PICKUP AND FEEDING SYSTEM...........................................................................................................................2-15
2.5.1 Overview/Configuration ............................................................................................................................................................ 2-15
2.5.1.1 Overview.......................................................................................................................................................................................................2-15
2.5.2 Detecting Jams........................................................................................................................................................................... 2-16
2.5.2.1 Jam Detection Outline...................................................................................................................................................................................2-16
2.5.2.1.1 Overview...............................................................................................................................................................................................2-16
2.5.2.2 Delay Jams....................................................................................................................................................................................................2-17
2.5.2.2.1 Delivery Delay Jam...............................................................................................................................................................................2-17
2.5.2.3 Stationary Jams .............................................................................................................................................................................................2-17
2.5.2.3.1 Pickup Stationary Jam...........................................................................................................................................................................2-17
2.5.2.3.2 Delivery Stationary Jam........................................................................................................................................................................2-17
2.5.2.4 Other Jams.....................................................................................................................................................................................................2-17
2.5.2.4.1 Fixing Take-up Jam...............................................................................................................................................................................2-17
2.5.2.4.2 Remaining Jam at Start-up....................................................................................................................................................................2-17
2.6 EXTERNAL AND CONTROLS SYSTEM................................................................................................................2-18
2.6.1 Power Supply............................................................................................................................................................................. 2-18
2.6.1.1 Power Supply ................................................................................................................................................................................................2-18
2.6.1.1.1 Low voltage power circuit.....................................................................................................................................................................2-18
2.6.1.2 Protective Functions......................................................................................................................................................................................2-19
2.6.1.2.1 Power protective function .....................................................................................................................................................................2-19

Contents
2.6.1.2.2 Safety function......................................................................................................................................................................................2-19
2.7 ENGINE CONTROL SYSTEM ................................................................................................................................. 2-20
2.7.1 Main Controller.......................................................................................................................................................................... 2-20
2.7.1.1 General description.......................................................................................................................................................................................2-20
2.7.2 Engine Controller....................................................................................................................................................................... 2-21
2.7.2.1 General description.......................................................................................................................................................................................2-21
2.8 FIXING UNIT/DELIVERY SYSTEM....................................................................................................................... 2-22
2.8.1 Overview/Configuration ............................................................................................................................................................ 2-22
2.8.1.1 Overview.......................................................................................................................................................................................................2-22
2.8.1.2 Main Parts of Fixing Unit.............................................................................................................................................................................2-22
2.8.2 Various Control Mechanisms .................................................................................................................................................... 2-23
2.8.2.1 Fixing Temperature Control .........................................................................................................................................................................2-23
2.8.2.1.1 Fixing Temperature Control .................................................................................................................................................................2-23
2.8.2.2 Protective Functions .....................................................................................................................................................................................2-24
2.8.2.2.1 Protective Function of Fixing Unit .......................................................................................................................................................2-24
2.8.2.2.2 Error detection ......................................................................................................................................................................................2-24
2.8.3 Other Functions.......................................................................................................................................................................... 2-25
2.8.3.1 Throughput Down Control............................................................................................................................................................................2-25

Chapter 2
2-1
2.1 Functional Configuration
2.1.1 Outline
0019-9506
The machine may be broadly divided into the following 6 functional blocks: engine control system, laser exposure system, image formation system, pickup/trans-
port/delivery system, fixing system, and externals/auxiliary control system.
F-2-1
2.2 Basic Sequence
2.2.1 Basic Sequence of Operation
0019-9507
The engine controller controls the operation sequence. The following table provides an outline of machine operation occurring from when the power switch is turned
on to when printing ends and motors stop, indicating the purposes of intervals and engine operation. For details of various loads, see the timing chart.
T-2-1
Interval Purpose Remarks
WAIT
(Wait) From power-ON until initial drive for main motor is completed. To clear potential from the drum surface and to clean the transfer roller.
Also to bring the heater temperature up to the
targeted temperature.
Detect whether the Toner cartridge is installed or
not.
STBY
(Standby) From the end of the WAIT period or the LSTR period until the print command is sent from the
main controller. Or, from the end of the LSTR
period until power switch is turned OFF.
To keep the printer ready to print.
INTR
(initial
rotation)
From the input of the print command from the
main controller until the pick-up solenoid is
turned ON.
To stabilize the photosensitive drum sensitivity
in preparation for printing. Also to clean the
transfer roller.
PRINT
(print) From the end of the INTR period until the top of page sensor detects the trailing edge of paper. Toform image on the photosensitive drum based on the VIDEO (/VD01, /VD02, VD01, VD02)
signals input from the main controller, and to
transfer the toner image onto paper.
LSTR
(last rotation) From the end of PRINT period until the Main motor stops. To deliver the last paper completely out of the printer. Return to the INTR period as soon as another print command is sent from the main controller.
External device
Engine control
system
Laser exposure system
Pickup/transport/delivery system
Image formation system
Fixing system
Externals and control system