Canon iR C6800 Series User manual

Apr 6 2004
Service Manual
iR C6800 Series
iR C6800C

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 reference 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, however, 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 communicated 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 Introduction
1.1 System Construction........................................................................................................................................... 11
1.1.1 System Configuration with Pickup/Delivery Accessories .......................................................................... 11
1.1.2 System Configuration with Printing/Transmission Accessories................................................................. 12
1.1.3 Functions of Printing/Transmitting Accessories......................................................................................... 13
1.2 Product Specifications........................................................................................................................................ 14
1.2.1 Names of Parts ............................................................................................................................................. 14
1.2.2 Using the Machine ....................................................................................................................................... 18
1.2.3 User Mode Items........................................................................................................................................ 111
1.2.4 User Maintenance ...................................................................................................................................... 118
1.2.5 Safety ......................................................................................................................................................... 122
1.2.6 Product Specifications ............................................................................................................................... 124
1.2.7 Function List .............................................................................................................................................. 127
Chapter 2 Installation
2.1 Making PreChecks ............................................................................................................................................ 21
2.1.1 Selecting the Site of Installation.................................................................................................................. 21
2.1.2 Installation Environment............................................................................................................................. 23
2.1.3 Checking the Contents................................................................................................................................. 24
2.2 Unpacking and Installation................................................................................................................................. 26
2.2.1 Before Starting the Work ............................................................................................................................ 26
2.2.2 Unpacking the Machine............................................................................................................................... 26
2.2.3 Mounting the Pickup Assembly .................................................................................................................. 29
2.2.4 Mounting the Scanner System..................................................................................................................... 29
2.2.5 Locking the Primary Transfer Roller in Place........................................................................................... 210
2.2.6 Before Mounting the Developing Assembly............................................................................................. 210
2.2.7 Mounting the Color Developing Assemblies ............................................................................................ 214
2.2.8 Mounting the Black Developing Assembly .............................................................................................. 217
2.2.9 Mounting the Process Unit........................................................................................................................ 219
2.2.10 Mounting the Fixing Assembly............................................................................................................... 223
2.2.11 Fitting the Black Toner Bottle................................................................................................................. 224
2.2.12 Checking the Environment Switch.......................................................................................................... 225
2.2.13 Turning On the Main Power Switch........................................................................................................ 226
2.2.14 Setting Up the Paper Cassette ................................................................................................................. 226
2.2.15 Changing the Deck Paper Size (right, left).............................................................................................. 227
2.2.16 Fitting the Color Toner Cartridge............................................................................................................ 228
2.2.17 Supplying Black Toner............................................................................................................................ 229
2.2.18 Cleaning the Intermediate Transfer Belt ................................................................................................. 229
2.2.19 Supplying Color Toner............................................................................................................................ 229
2.2.20 Setting Auto Gradation Correction.......................................................................................................... 230
2.2.21 Checking the Image/Operation................................................................................................................ 230
2.2.22 Adjusting the Horizontal Registration..................................................................................................... 230
2.2.23 Adjusting the Leading Edge Registration ............................................................................................... 233
2.2.24 Securing the Machine in Place ................................................................................................................ 233
2.2.25 If Not Connected to a Network ............................................................................................................... 234

Contents
2.3 Checking the Connection to the Network.........................................................................................................235
2.3.1 Overview....................................................................................................................................................235
2.3.2 Using the PING Utility ..............................................................................................................................235
2.3.3 Using a Remote Host Address...................................................................................................................235
2.4 Troubleshooting the Network...........................................................................................................................236
2.4.1 Overview....................................................................................................................................................236
2.4.2 Checking the Connection of the Network Cable .......................................................................................236
2.4.3 Using a Loopback Address........................................................................................................................236
2.4.4 Using a Local Host Address ......................................................................................................................236
2.5 Relocating the Machine....................................................................................................................................237
2.5.1 Relocating the Machine .............................................................................................................................237
2.6 Installing the Card ReaderC1 ..........................................................................................................................238
2.6.1 Points to Note About Installation ..............................................................................................................238
2.6.2 Checking the Contents...............................................................................................................................238
2.6.3 Installation .................................................................................................................................................239
2.6.4 Using the Card Reader in Combination with NetSpot Accountant (hereafter, NSA) ...............................241
2.7 Installing the NE ControllerA1 .......................................................................................................................242
2.7.1 NE ControllerA1 Installation Procedure ..................................................................................................242
2.8 Installing the Original Tray ..............................................................................................................................251
2.8.1 Checking the Contents...............................................................................................................................251
2.8.2 Installation .................................................................................................................................................251
2.9 Installing the Key Switch UnitA1 ...................................................................................................................253
2.9.1 Checking the Contents...............................................................................................................................253
2.9.2 Installation .................................................................................................................................................253
Chapter 3 Basic Operation
3.1 Construction........................................................................................................................................................31
3.1.1 Functional Construction...............................................................................................................................31
3.1.2 Arrangement of the Major PCBs.................................................................................................................33
3.1.3 DC Controller ..............................................................................................................................................34
3.2 Basic Sequence ...................................................................................................................................................36
3.2.1 Basic Sequence of Operation at PowerOn .................................................................................................36
3.2.2 Basic Sequence of Control During Printing (fullcolor)..............................................................................38
3.2.3 Basic Sequence of Operation During Printing (mono color).......................................................................39
Chapter 4 Main Controller
4.1 Construction........................................................................................................................................................41
4.1.1 Functional Construction...............................................................................................................................41
4.2 Construction of the Electrical Circuitry..............................................................................................................43
4.2.1 Main Controller PCB (main) .......................................................................................................................43
4.2.2 Main Controller PCB (sub)..........................................................................................................................45
4.2.3 Expansion Bus PCB.....................................................................................................................................46
4.2.4 SRAM PCB .................................................................................................................................................46
4.2.5 HDD.............................................................................................................................................................47
4.3 StartUp Sequence ..............................................................................................................................................49
4.3.1 Overview......................................................................................................................................................49
4.3.2 StartUp Sequence .....................................................................................................................................410
4.4 Actions when HDD Error .................................................................................................................................412
4.4.1 E602 in Detail............................................................................................................................................412
4.4.2 E609 in Detail............................................................................................................................................416

Contents
4.5 Image Processing.............................................................................................................................................. 417
4.5.1 Overview of the Flow of Image Data........................................................................................................ 417
4.5.2 Construction of the Image Processing Modules........................................................................................ 418
4.5.3 Reader Input Image Processing................................................................................................................. 419
4.5.4 Compression/Decompression and Editing Blocks .................................................................................... 420
4.5.5 Printer Output Image Processing............................................................................................................... 421
4.6 Flow of Image Data.......................................................................................................................................... 422
4.6.1 Flow of Image Data (copier function)....................................................................................................... 422
4.6.2 Flow of Image Data (Box function) .......................................................................................................... 423
4.6.3 Flow of Image Data (SEND function) ...................................................................................................... 424
4.6.4 Flow of Image Data (fax transmission)..................................................................................................... 425
4.6.5 Image Data Flow for Fax Reception Functions......................................................................................... 426
4.6.6 Flow of Image Data (PDL function) ......................................................................................................... 427
4.7 Parts Replacement Procedure........................................................................................................................... 428
4.7.1 Controller Box ........................................................................................................................................... 428
4.7.2 Main Controller PCB (main) ..................................................................................................................... 431
4.7.3 Main Controller PCB (sub)........................................................................................................................ 435
4.7.4 Expansion Bus PCB................................................................................................................................... 436
4.7.5 SRAM PCB................................................................................................................................................ 438
4.7.6 UFR Board ................................................................................................................................................. 440
4.7.7 Ethernet Board ........................................................................................................................................... 441
4.7.8 HDD........................................................................................................................................................... 443
4.7.9 Controller Fan ............................................................................................................................................ 445
Chapter 5 Original Exposure System
5.1 Construction ....................................................................................................................................................... 51
5.1.1 Specifications, Control Mechanisms, and Functions .................................................................................. 51
5.1.2 Major Components...................................................................................................................................... 52
5.1.3 Construction of the Control System ............................................................................................................ 54
5.1.4 Reader Controller PCB................................................................................................................................ 54
5.2 Basic Sequence................................................................................................................................................... 56
5.2.1 Basic Sequence of Operation at PowerOn ................................................................................................. 56
5.2.2 Basic Sequence of Operation in Response to a Press on the Start Key.......................................................57
5.3 Various Control .................................................................................................................................................. 59
5.3.1 Controlling the Scanner Drive System ........................................................................................................ 59
5.3.2 Enlargement/Reduction.............................................................................................................................. 511
5.3.3 Controlling the Scanning Lamp................................................................................................................. 511
5.3.4 Detecting the Size of Originals.................................................................................................................. 512
5.3.5 Dirt Sensor Control.................................................................................................................................... 516
5.3.6 Image Processing ....................................................................................................................................... 520
5.4 Parts Replacement Procedure........................................................................................................................... 523
5.4.1 Copyboard Glass........................................................................................................................................ 523
5.4.2 Exposure Lamp .......................................................................................................................................... 523
5.4.3 Reader Controller PCB .............................................................................................................................. 527
5.4.4 Interface PCB............................................................................................................................................. 530
5.4.5 Inverter PCB .............................................................................................................................................. 532
5.4.6 CCD Unit ................................................................................................................................................... 533
5.4.7 Scanner Motor............................................................................................................................................ 535
5.4.8 ADF Open/Close Sensor............................................................................................................................ 537
5.4.9 Scanner HP Sensor..................................................................................................................................... 539
5.4.10 Original Sensor ........................................................................................................................................ 541
5.4.11 Cooling Fan.............................................................................................................................................. 542
5.4.12 Scanner Drive Cable ................................................................................................................................ 543

Contents
Chapter 6 Laser Exposure
6.1 Construction........................................................................................................................................................61
6.1.1 Specifications, Control Mechanisms, and Functions...................................................................................61
6.1.2 Major Components ......................................................................................................................................62
6.1.3 Construction of the Control System ............................................................................................................63
6.2 Basic Sequence ...................................................................................................................................................64
6.2.1 Basic Sequence of Operation.......................................................................................................................64
6.3 Various Control ..................................................................................................................................................65
6.3.1 Controlling the Laser Activation Timing.....................................................................................................65
6.3.2 Controlling the Intensity of Laser Light.......................................................................................................68
6.3.3 Controlling the Laser Scanner Motor...........................................................................................................69
6.3.4 Controlling the Laser Shutter .....................................................................................................................610
6.4 Parts Replacement Procedure ...........................................................................................................................611
6.4.1 Laser Scanner Unit.....................................................................................................................................611
Chapter 7 Image Formation
7.1 Construction........................................................................................................................................................71
7.1.1 Specifications of the Image Formation System...........................................................................................71
7.1.2 Major Components ......................................................................................................................................74
7.1.3 Charging System..........................................................................................................................................75
7.2 Image Formation Process ...................................................................................................................................77
7.2.1 Image Formation Process ............................................................................................................................77
7.3 Basic Sequence ...................................................................................................................................................79
7.3.1 At Time of PowerOn ..................................................................................................................................79
7.3.2 During Copying/Printing (normal speed)..................................................................................................710
7.3.3 During Copying/Printing (2/3 speed, 1/3 speed) .......................................................................................710
7.4 Image Stabilization Control..............................................................................................................................711
7.4.1 Overview of Image Stabilization Control..................................................................................................711
7.4.2 Timing of Image Stabilization Control......................................................................................................712
7.4.3 Potential Control........................................................................................................................................715
7.4.4 ATVC Control ...........................................................................................................................................719
7.4.5 ATR Control..............................................................................................................................................721
7.4.6 ACR Control (Auto Carrier Refresh Control) ...........................................................................................724
7.4.7 Dmax Control...........................................................................................................................................725
7.4.8 Dhalf Control............................................................................................................................................726
7.4.9 PASCAL control .......................................................................................................................................729
7.5 Charging Meachanism......................................................................................................................................732
7.5.1 Controlling the Primary Charging Bias .....................................................................................................732
7.5.2 Controlling the Primary Charging Assembly Cleaning Mechanism .........................................................733
7.5.3 Controlling the PreTransfer Charging Bias..............................................................................................734
7.5.4 Controlling the PreTransfer Charging Assembly Cleaning Mechanism..................................................734
7.5.5 PreExposure LED.....................................................................................................................................736
7.6 Developing Rotary............................................................................................................................................737
7.6.1 Overview of the Developing Rotary..........................................................................................................737
7.6.2 Controlling the Developing Rotary ...........................................................................................................738
7.7 Developing Unit................................................................................................................................................741
7.7.1 Construction of the Color Developing Assembly......................................................................................741
7.7.2 Controlling the Color Developing Assembly Drive Mechanism ..............................................................742
7.7.3 Controlling the Color Developing Bias .....................................................................................................743
7.7.4 Color Toner Supply ...................................................................................................................................744
7.7.5 Detecting the Level of Color Toner...........................................................................................................745
7.7.6 Construction of the Black Developing Assembly .....................................................................................748