Canon NP6251 User manual

SERVICE
MANUAL
REVISION 0
FY8-13F0-000
JULY 1997
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)

IMPORTANT
THIS DOCUMENTATION IS PUBLISHED BY CANON INC., JAPAN, TO SERVE AS A SOURCE OF
REFERENCE FOR WORK IN THE FIELD.
SPECIFICATIONS AND OTHER INFORMATION CONTAINED HEREIN MAY VARY SLIGHTLY FROM
ACTUAL MACHINE VALUES OR THOSE FOUND IN ADVERTISING AND OTHER PRINTED
MATTER.
ANY QUESTIONS REGARDING INFORMATION CONTAINED HEREIN SHOULD BE DIRECTED TO
THE COPIER SERVICE DEPARTMENT OF THE SALES COMPANY.
THIS DOCUMENTATION IS INTENDED FOR ALL SALES AREAS, AND MAY CONTAIN
INFORMATION NOT APPLICABLE TO CERTAIN AREAS.
COPYRIGHT © 1997 CANON INC.
Printed in Japan
Imprimé au Japon
Use of this manual should be
strictly supervised to avoid
disclosure of confidential
information.
Prepared by
OFFICE IMAGING PRODUCTS TECHNICAL SUPPORT DEPARTMENT 1
OFFICE IMAGING PRODUCTS TECHNICAL SUPPORT DIVISION
CANON INC.
5-1, Hakusan 7-chome, Toride-shi, Ibaraki 302 Japan
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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This Service Manual contains basic data and figures on the plain paper copier
NP6350/NP6251 needed to service the machine in the field.
The NP6350/NP6251 is designed to enable full automatic copying work, and comes
with the following systems accessories:
1. Stapler Sorter-E2
2. RDF-D1
3. Paper Deck-A1
4. Sorter-G1
This Service Manual covers the copier only, and consists of the following chapters:
Chapter 1 General Description introduces the copier’s features and specifications,
shows how to operate the copier, and explains how copies are made.
Chapter 2 Basic Operation provides outlines of the copier's various mechanical
workings.
Chapter 3 Exposure System discusses the principles of operation used for the
copier's lens drive unit and scanner drive unit. It also explains the timing
at which these drive units are operated, and shows how they may be
disassembled/assembled and adjusted.
Chapter 4 Image Formation System discusses the principles of how images are
formed. It also explains the timing at which the various units involved in
image formation are operated, and shows how they may be
disassembled/assembled and adjusted.
Chapter 5 Pick-Up/Feeding System explains the principles used from when copy
paper is picked up to when a copy is delivered in view of the functions of
electrical and mechanical units and in relation to their timing of operation.
It also shows how these units may be disassembled/assembled and
adjusted.
Chapter 6 Fixing System explains the principles used to fuse toner images to
transfer media in view of the functions of electrical and mechanical units
and in relation to their timing of operation. It also shows how these units
may be disassembled/assembled and adjusted.
Chapter 7 Externals/Auxiliary Mechanisms shows the copier’s external parts, and
explains the principles used for the copier’s various control mechanisms
in view of the functions of electrical and mechanical units and in relation
to their timing of operation. It also shows how these units may be
disassembled/assembled and adjusted.
Chapter 8 Paper Deck-A1 explains the principles used from when copy paper is
picked up to when a copy is delivered in view of the functions of electrical
and mechanical units and in relation to their timing of operation. It also
shows how these units may be disassembled/assembled and adjusted.
Chapter 9 Installation introduces requirements for the site of installation, and shows
how the copier may be installed using step-by-step instructions.
Chapter 10 Maintenance and Servicing provides tables of periodically replaced parts
and consumables/durables and scheduled servicing charts.
INTRODUCTION

Chapter 11 Troubleshooting provides tables of maintenance/inspection,
standards/adjustments, and problem identification (image
fault/malfunction).
Appendix contains a general timing chart and general circuit diagrams.
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 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.
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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System Configuration
The NP6350/NP6251 is designed to accommodate the following accessories:
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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Stapler Sorter-E2
RDF-D1
NP6350/NP6251
(front paper deck + cassette type)
Paper Deck-A1
Sorter G1
Control Card V
It feeds a stack of originals to
the copier, sheet by sheet.
It allows control of
copy volume.
It can automatically sort
and group copies.
It can accommodate
as many as 3,500
sheets of
A4/B5/LTR paper.
In addition to the
functions of the 20-Bin
Stapler Sorter, it can
automatically staple
sorted copies.
It also is equipped with
a front access function,
in which copies may be
removed from the front,
and a multiple stacking
function, in which two or
more sets may be
delivered in a single bin.

1. GENERAL DESCRIPTION
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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CONTENTS
CHAPTER 1 GENERAL DESCRIPTION
I. FEATURES.........................................1-1
II. SPECIFICATIONS..............................1-2
A. Copier............................................1-2
1. Type..........................................1-2
2. Mechanisms .............................1-2
3. Performance.............................1-3
4. Others.......................................1-6
B. Paper Deck-A1..............................1-9
III. NAMES OF PARTS............................1-10
A. External View.................................1-10
B. Cross Section................................1-12
1. Copier.......................................1-12
IV. OPERATING THE MACHINE.............1-13
A. Control Panel.................................1-13
B. Extended Modes ...........................1-14
C. User Mode.....................................1-15
1. Types of User Modes...............1-15
V. ROUTINE MAINTENANCE BY THE
USER..................................................1-19
VI. POINTS TO NOTE (BY THE USER) .1-19
VII. IMAGE FORMATION..........................1-20
A. Outline...........................................1-20
CHAPTER 2 BASIC OPERATION
I. BASIC MECHANISMS .......................2-1
A. Functional Construction.................2-1
B. Outline of the Electrical Circuitry...2-2
C. Basic Sequence of Operations......2-4
1. Basic Sequence of Operations
at Power-On (1/2).....................2-4
2. Basic Sequence of Operations
at Power-On (2/2).....................2-5
3. Basic Sequence of
Operations................................2-7
4. Basic Sequence of Operations
in Page Separation Mode.........2-9
D. Main Motor (M1) Control Circuitry..2-11
1. Outline......................................2-11
2. Operation..................................2-12
3. Detecting an Error....................2-12
E. Inputs to the DC Controller............2-13
F. Outputs from the DC Controller.....2-21
G. Inputs to and Outputs from
Accessories...................................2-32
CHAPTER 3 EXPOSURE SYSTEM
I. OUTLINE OF OPERATION................3-1
A. Varying the Reproduction Ratio.....3-1
II. LENS DRIVE SYSTEM ......................3-2
A. Moving of the Lens........................3-2
1. Outline of the Movement..........3-2
2. Moving the Lens.......................3-3
3. Lens Motor Control Circuit .......3-3
4. Moving the Lens.......................3-4
III. SCANNER DRIVE SYSTEM..............3-6
A. Scanner Movement .......................3-6
1. Outline of Movement................3-6
2. Relationship between the
Scanner Sensors and the
Signals......................................3-7
3. Basic Sequence of Operations..3-8
4. Movement of the Scanner in
Page Separation Mode ............3-9
5. Movement of the Scanner with
the RDF in Use (A4, 2 originals,
1 copy)......................................3-11
6. Movement of the Scanner with
the RDF in Use (A4, 2 copies)..3-13
7. Scanner Motor (M3) Control
Circuit .......................................3-17
IV. OTHERS.............................................3-20
A. Original Size Detection..................3-20
1. Outline of Detection..................3-20
2. Operation..................................3-21
3. Sizes of Originals .....................3-22
V. DISASSEMBLY AND ASSEMBLY......3-23
A. Scanner Drive Assembly...............3-24
1. Removing the Scanner Drive
Motor ........................................3-24

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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I. PROCESSES .....................................4-1
A. Controlling the Drum Surface
Potential.........................................4-1
1. Outline......................................4-1
2. Control Method.........................4-2
3. Potential Measurement Circuit..4-4
B. Controlling the Intensity of the
Scanning Lamp .............................4-6
1. Outline......................................4-6
2. Operation..................................4-7
3. Auto Exposure Control.............4-7
4. Making Checks.........................4-10
C. Controlling the Primary/Transfer
Corona Current..............................4-11
1. Outline......................................4-11
2. Controlling the Primary
Corona Current.........................4-11
3. Controlling the Transfer
Corona Current.........................4-13
D. Controlling the Separation/Pre-
Transfer Corona Current ...............4-15
1. Outline......................................4-15
2. Turning ON and OFF the
Separation/ Pre-Transfer
Corona Current.........................4-16
3. Separation Corona Current
(DC component).......................4-17
4. Pre-Transfer Corona Current
(DC component).......................4-17
5. Controlling the DC Component
of the Separation/Pre-Transfer
Corona Current.........................4-18
E. Controlling the Blanking Exposure
Lamp (LED)...................................4-19
1. Outline......................................4-19
2. Controlling the Activation in
Reduce Mode...........................4-19
3. Controlling the Activation in
Direct Mode..............................4-19
4. Controlling the Activation in
Sheet Frame Erase Mode........4-19
5. Controlling the Activation in
Original Frame Erase Mode.....4-20
6. Controlling the Activation in
Book Frame Erase Mode.........4-20
7. Controlling the Activation in
Hole Image Erase Mode ..........4-21
8. Controlling the Activation in
AE Mode...................................4-21
F. Drum Heater Circuit.......................4-22
1. Outline......................................4-22
2. Idle Rotation of the
Photosensitive Drum and the
Developing Cylinder.................4-24
G. Cleaning the Primary Charging
Wire...............................................4-25
1. Outline......................................4-25
2. Automatic Cleaning
Mechanism...............................4-25
H. Pre-Transfer/Transfer/Separation
Charging Wire Automatic
Cleaning Mechanism.....................4-26
II. DRUM CLEANING ASSEMBLY
/DEVELOPING ASSEMBLY...............4-28
A. Outline...........................................4-28
B. Detecting the Level of Toner and
Controlling the Supply Operation ..4-30
C. Controlling the Developing
Bias/Roller Electrode.....................4-32
1. Outline......................................4-32
2. Control Timing..........................4-32
3. Developing Bias Control
Circuit .......................................4-35
4. Roller Electrode Bias Control
Circuit .......................................4-36
D. Detecting the Waste Toner Feeding
Screw (locking)..............................4-38
III. DISASSEMBLY AND ASSEMBLY......4-39
CHAPTER 4 IMAGE FORMATION SYSTEM
2. Routing the Scanner Drive
Cable........................................3-26
3. Orienting the Heat Absorbing
Glass ........................................3-26
4. Removing the Scanner Drive
Cable........................................3-27
5. Adjusting the Tension of the
Scanner Drive Cable................3-29
6. Positioning the Mirror ...............3-29
7. Adjusting the Scanner Home
Position.....................................3-30
8. Positioning the Scanner Locking
Solenoid (SL1)..........................3-31
B. Lens Drive Assembly.....................3-32
1. Removing the Lens Y Direction
Drive Motor...............................3-32
2. Removing the Lens Stage
Temporarily...............................3-34
3. Installing the Light-Blocking
Belt Mount................................3-35
4. Removing the Lens X Direction
Drive Motor...............................3-36
5. Attaching the Lens X Direction
Drive Belt..................................3-37
6. Routing the Light-Blocking
Belt ...........................................3-37
7. Replacing the Light-
Blocking Belt.............................3-38

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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A. Scanning Lamp Assembly.............4-39
1. Removing the Scanning Lamp.4-39
2. Removing the Thermal Fuse....4-41
B. Standard White Plate ....................4-41
C. Pre-Exposure Lamp Unit...............4-43
1. Removing the Pre-Exposure
Lamp Unit.................................4-43
D. Blanking Exposure Lamp
Assembly.......................................4-44
1. Removing the Blanking
Exposure Lamp Assembly .......4-44
E. Photosensitive Drum .....................4-45
1. Removing the Drum Unit..........4-45
2. Replacing the Drum Heater......4-47
3. Installing the Photosensitive
Drum.........................................4-47
F. Potential Sensor Assembly ...........4-48
1. Removing the Potential
Sensor Assembly .....................4-48
G. Primary Charging Assembly..........4-48
1. Removing the Primary
Charging Assembly..................4-48
H. Pre-Transfer Charging Assembly..4-49
1. Removing the Pre-Transfer
Charging Assembly..................4-49
I. Transfer/Separation Charging
Assembly.......................................4-49
1. Removing the Transfer/
Separation Charging
Assembly..................................4-49
2. Installing the Transfer/
Separation Charging
Assembly..................................4-51
J. Charging Wire ...............................4-53
1. Outline......................................4-53
2. Removing the Wire Cleaner of
the Primary Charging
Assembly..................................4-53
3. Stringing the Charging Wires...4-53
4. Stringing the Grid Wire of the
Primary Charging Assembly.....4-56
5. Adjusting the Height of the
Charging Wire ..........................4-58
6. Cleaning the Primary Charging
Assembly Anti-Stray Sheet ......4-59
K. Developing Assembly....................4-60
1. Removing the Developing
Assembly from the Copier........4-60
2. Removing the Blade Unit .........4-61
3. Installing the Blade...................4-61
4. Removing the Developing
Cylinder and the Magnetic
Seal ..........................................4-62
5. Cleaning the Developing
Assembly Anti-Stray Sheet ......4-65
L. Hopper Assembly..........................4-66
1. Removing the Hopper
Assembly from the Copier........4-66
M. Drum Cleaner................................4-67
1. Construction .............................4-67
2. Removing the Cleaning Blade..4-67
3. Installing the Cleaning Blade....4-68
4. Installing the Side Seal.............4-69
5. Cleaning the Cleaning Side
Scraper.....................................4-70
N. Separation Claw/Separation
Claw Drive Assembly ....................4-71
1. Removing from the Drum Unit .4-71
O. Waste Toner Feeding Assembly....4-72
CHAPTER 5 PICK-UP/FEEDING SYSTEM
I. PICK-UP/FEEDING SYSTEM............5-1
A. Outline...........................................5-1
II. CASSETTE PICK-UP.........................5-4
A. Pick-Up Operation.........................5-4
1. Outline......................................5-5
2. Sequence of Pick-Up
Operations................................5-5
B. Cassette Lifter Operation ..............5-6
C. Identifying the Size of Copy
Paper in the Cassette....................5-8
1. Outline......................................5-8
2. Identifying the Size of Copy
Paper........................................5-8
3. Markings on the Width Guide
Rail ...........................................5-10
4. Paper Size................................5-11
5. Registering Paper Width Basic
Value.........................................5-12
III. FRONT PAPER DECK ASSEMBLY ......5-13
A. Outline...........................................5-13
1. Pick-Up Operation....................5-14
2. Sequence of Pick-Up
Operations................................5-15
B. Lifter Operation..............................5-16
1. Operation..................................5-16
2. Deck Limit Detection ................5-18
C. Detecting the Presence/Absence
of Paper in the Deck......................5-19
1. Detecting the Presence/
Absence of Paper in the Deck..5-19
2. Detecting the Size of the Deck..5-19
D. High-Speed Pick-Up......................5-19
IV. MULTIFEEDER...................................5-20
A. Pick-Up Operation.........................5-20
B. Identifying the Size of Paper in
the Multifeeder...............................5-21

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C. Sequence of Pick-Up Operations
(multifeeder) ..................................5-22
V. CONTROLLING THE
REGISTRATION CLUTCH .................5-23
VI. MAKING TWO-SIDED/OVERLAY
COPIES..............................................5-24
A. Making Two-Sided/Overlay
Copies (1st side) ...........................5-24
1. Sequence of Operations
(two-sided/overlay copies;
1st side)....................................5-25
B. Making Two-Sided Copies
(2nd side) ......................................5-26
1. Sequence of Operations
(two-sided copying; 2nd side) ..5-27
C. Making Overlay Copies
(2nd side) ......................................5-28
1. Outline......................................5-28
2. Outline of Operation.................5-29
3. Sequence of Operations
(overlay copying; 2nd side)......5-31
D. Reversal Delivery ..........................5-32
1. Sequence of Reversal
Delivery Operations..................5-33
E. Switching the Paper Size for Two-
Sided/Overlay/Reversal Delivery
Copies ...........................................5-34
1. Movement of the Paper Size
Guide........................................5-34
2. Movement of the Paper
Jogging Plate and the Trailing
Edge Guide Plate.....................5-35
3. Detecting the Presence/
Absence of Copy Paper...........5-36
F. Re-Pick Up from the Holding
Tray................................................5-37
G. Skipping Operation........................5-38
1. Outline......................................5-38
2. Outline of Operations ...............5-39
3. Skipping Operation (odd
number of originals) .................5-41
4. Skipping Operation (odd
number of originals) .................5-42
5. Reversal Delivery.....................5-45
VII. DETECTING JAMS............................5-46
A. Outline...........................................5-46
1. Registration Roller Delay Jam..5-49
2. Registration Roller Stationary
Jam...........................................5-49
3. Pick-Up Vertical Path Feeding
0/1 Delay Jam ..........................5-50
4. Pick-Up Vertical Path Feeding
0/1 Stationary Jam ...................5-50
5. Pick-Up Vertical Path Feeding
2 through 4 Delay Jam.............5-51
6. Pick-Up Vertical Path Feeding
2 through 4 Stationary Jam......5-51
7. Fixing Assembly Outlet Delay
Jam...........................................5-52
8. Fixing Assembly Outlet
Stationary Jam .........................5-52
9. External Delivery Delay Jam....5-53
10.External Delivery Stationary
Jam...........................................5-53
11.Internal Delivery Delay Jam.....5-54
12.Internal Delivery Stationary
Jam...........................................5-54
13.Holding Tray Inlet Delay Jam...5-55
14.Holding Tray Inlet Stationary
Jam...........................................5-55
15.Holding Tray Re-Pick Up Delay
Jam...........................................5-56
16.Holding Tray Registration
Delay Jam ................................5-56
17.Holding Tray Registration
Stationary Jam .........................5-57
18.Holding Tray Feeding 1/2
Delay Jam ................................5-57
19.Holding Tray Feeding 1/2
Stationary Jam .........................5-58
20.Left Deck Pick-Up Delay Jam..5-58
21.Left Deck Pick-Up Stationary
Jam...........................................5-59
22.Fixing Separation Claw
Assembly Stationary Jam.........5-59
VIII. DISASSEMBLY AND ASSEMBLY......5-60
A. Multifeeder Assembly....................5-61
1. Removing the Multifeeder
Assembly..................................5-61
2. Removing the Pick-Up Roller...5-61
3. Installing the Pick-Up Roller.....5-62
4. Removing the Separation
Roller........................................5-63
5. Removing the Feeding Roller...5-65
6. Removing the Multifeeder
Paper Sensor ...........................5-66
7. Attaching the Side Guide
Timing Belt in the Multifeeder
Assembly..................................5-68
8. Installing the Feeding Roller of
the Multifeeder..........................5-69
9. Adjusting the Pressure of the
Pick-Up/Feeding Roller of the
Multifeeder................................5-69
10.Position of the Pick-Up Roller
Releasing Solenoid of the
Multifeeder................................5-70
B. Front Paper Deck Assembly .........5-71
1. Removing the Paper Deck
Assembly from the Copier........5-71
2. Removing the Lifter Cable........5-72
3. Changing the Deck Paper Size..5-77
4. Adjusting the Deck
Registration ..............................5-79
C. Right Deck Pick-Up Assembly
(cassette holder)............................5-80
1. Removing the Pick-Up
Assembly from the Copier........5-80

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2. Removing the Pick-Up Roller...5-80
3. Removing the Feeding Roller...5-82
4. Removing the Separation
Roller........................................5-82
5. Adjusting the Pressure of the
Separation Roller......................5-84
6. Orientation of the Separation
Roller........................................5-85
7. Orientation of the Feeding
Roller of the Cassette/Deck
Pick-Up Assembly....................5-86
8. Positioning the Pick-Up Roller
Releasing Solenoid of the
Deck .........................................5-86
9. Positioning of the Pick-Up Roller
Releasing Solenoid of the
Cassette ...................................5-87
10.Adjusting the Registration of
the Cassette.............................5-87
D. Left Deck Pick-Up Assembly.........5-88
1. Removing the Pick-Up
Assembly from the Copier........5-88
2. Removing the Pick-Up Roller...5-88
3. Removing the Feeding Roller...5-90
4. Removing the Separation
Roller........................................5-90
5. Orientation of the Feeding
Roller Assembly of the Left
Deck Pick-Up Assembly...........5-91
E. Pick-Up Vertical Path Roller
Assembly.......................................5-92
1. Removing the Pick-Up Vertical
Path Roller Assembly...............5-92
F. Registration Feeding Assembly.....5-93
1. Construction .............................5-93
2. Removing the Registration
Feeding Assembly....................5-93
3. Removing the Registration
Roller (upper rubber roller).......5-94
G. Feeding Assembly.........................5-96
1. Construction .............................5-96
2. Removing the Fixing/Feeding
Unit...........................................5-96
3. Removing the Feeding Belt......5-97
H. Holding Tray Assembly..................5-101
1. Construction .............................5-101
2. Removing the Holding Tray
from the Copier ........................5-102
3. Removing the Holding Tray
Re-Pick Up Assembly ..............5-102
4. Removing the Holding Tray
Registration Paper Sensor.......5-103
5. Removing the Re-Pick Up
Roller........................................5-104
6. Removing the Holding Tray
Driver PCB ...............................5-104
7. Removing the Holding Tray Y
Motor ........................................5-105
8. Removing the Y Motor Home
Position Sensor........................5-107
9. Removing the Holding Tray
Inlet Assembly..........................5-107
10.Removing the Feeding
Roller/Separation Belt
Assembly..................................5-109
11.Removing the Feeding Roller...5-110
12.Removing the Separation Belt
Assembly..................................5-111
13.Adjusting the Pressure of the
Separation Roller of the
Holding Tray.............................5-111
14.Positioning the Holding Tray
Paper Deflecting Plate Drive
Solenoid ...................................5-112
15.Removing the Side Guide
Plate Assembly.........................5-112
16.Removing the Holding Tray X
Motor ........................................5-113
17.Removing the Holding Tray
Re-Circulating Motor ................5-113
18.Removing the Holding Tray
Paper Jogging Solenoid...........5-114
19.Installing the Holding Tray
Paper Jogging Guide Plate
Assembly..................................5-116
20.Installing the Holding Tray
Assembly Side Guide Plate
Assembly..................................5-116
21.Attaching the Timing Belt of
the Holding Tray Assembly
Paper Jogging Guide Plate......5-117
22.Positioning the Holding Tray
Paper Jogging Solenoid...........5-117
I. Holding Tray Feeding Assembly ...5-118
1. Removing the Holding Tray
Feeding Assembly from the
Copier.......................................5-118
2. Removing the Sensor from the
Holding Tray Feeding
Assembly..................................5-119
CHAPTER 6 FIXING SYSTEM
I. OUTLINE OF OPERATIONS..............6-1
A. Outline...........................................6-1
B. Fixing Drive Assembly...................6-3
C. Controlling the Fixing Temperature..6-5
D. Reciprocating Mechanism for
the Main Thermistor (TH1)............6-10

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CHAPTER 7 EXTERNALS/AUXILIARY MECHANISMS
I. CONTROL PANEL .............................7-1
A. Outline...........................................7-1
B. Operation.......................................7-1
1. Data Communication................7-1
2. LCD Processing .......................7-2
3. Automatic Control of LCD
Contrast....................................7-4
4. Touch Switch Inputs .................7-5
II. FANS ..................................................7-6
III. POWER SUPPLY...............................7-9
A. Outline of Power Supply................7-9
B. Power Supply Circuit.....................7-10
C. Date/Time Display Power Supply..7-12
IV. DISASSEMBLY AND ASSEMBLY......7-13
A. External Covers.............................7-14
1. Removing the Front Door.........7-15
2. Removing the Inside Upper
Cover........................................7-16
3. Removing the Fixing/Feeding
Unit Front Cover.......................7-17
4. Removing the Rear Cover........7-17
5. Sliding Out the Hopper
Assembly..................................7-18
6. Removing the Process Unit......7-18
7. Installing the Process Unit........7-21
B. Control Panel.................................7-22
1. Removing the Control Panel
from the Copier ........................7-22
2. Removing the Control Panel
PCB..........................................7-25
3. Removing the Touch Panel......7-26
4. Removing the Control Panel
Controller (CPU) PCB ..............7-27
C. Door Switch Assembly ..................7-28
1. Removing the Front Door
Switch Assembly......................7-28
2. Removing the Multifeeder
Door Switch Assembly .............7-28
3. Installing the Drum Heater
Switch.......................................7-29
D. Fan Unit.........................................7-30
1. Removing the Scanner
Cooling Fan..............................7-30
2. Removing the Exhaust Fan......7-30
3. Removing the Fixing Heat
Exhaust Fan.............................7-31
E. Reciprocating Mechanism for
the Upper Separation Claw...........6-11
F. SSR Error Detection Circuit for
the Fixing Heater...........................6-12
G. Locking Operation (fixing/feeding
unit)................................................6-14
H. Error Detection Circuit...................6-15
1. Outline......................................6-15
2. Scanning Lamp Error
Activation Detection Circuit ......6-15
3. Fixing Heater Error Activation
Detection Circuit.......................6-16
4. Motor Error Rotation
Detection Circuit.......................6-17
II. DISASSEMBLY AND ASSEMBLY......6-18
A. Fixing Assembly ............................6-19
1. Construction .............................6-19
2. Locking Mechanism..................6-19
3. Removing the Fixing Cleaning
Belt ...........................................6-20
4. Installing the Fixing Cleaning
Belt ...........................................6-22
5. Removing the Upper Fixing
Unit...........................................6-23
6. Removing the Fixing Heater.....6-25
7. Installing the Fixing Heater.......6-27
8. Removing the Fixing Upper
Roller........................................6-27
9. Installing the Upper Fixing
Roller........................................6-29
10.Removing the Thermal Switch..6-30
11.Removing the Main Thermistor
(TH1) ........................................6-30
12.Removing the Lower
Separation Claw Assembly ......6-31
13.Removing the Lower Roller......6-32
14.Removing the Upper
Separation Claw.......................6-32
15.Adjusting the Nip (tightening
the pressure adjusting nut).......6-33
16.Adjusting the Fixing Clutch.......6-34
17.Removing the Sub Thermistor
(TH2) ........................................6-35
B. Delivery Assembly.........................6-36
1. Construction .............................6-36
2. Removing the Delivery Upper
Guide (fixing/delivery
assembly).................................6-36
3. Removing the Fixing/Feeding
Assembly Locking Assembly....6-37
4. Removing the External
Delivery Roller..........................6-37
5. Removing the External Delivery
Paper Sensor and the Internal
Delivery Paper Sensor .............6-39
6. Removing the Fixing Assembly
Outlet Paper Sensor
Assembly..................................6-39
7. Removing the Internal Delivery
Assembly Roller .......................6-40

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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4. Removing the Developing
Fan ...........................................7-31
5. Removing the Cleaner Fan......7-32
6. Removing the Feeding Fan......7-33
E. Removing the Counter Assembly..7-33
F. Main Motor Assembly....................7-34
1. Removing the Main Motor........7-34
G. Fixing/Waste Toner Drive
Assembly.......................................7-35
1. Construction .............................7-35
2. Removing the Waste Toner
Bottle ........................................7-35
3. Removing the Fixing/Waste
Toner Drive Assembly ..............7-35
H. Main Drive Assembly (drum/
developing)....................................7-38
1. Construction .............................7-38
2. Removing .................................7-38
I. Vertical Path Drive Assembly........7-40
1. Construction .............................7-40
2. Removing .................................7-40
J. Pick-Up Drive Assembly................7-42
1. Construction .............................7-42
2. Removing .................................7-43
K. Duplexing Drive (1) Assembly.......7-44
1. Construction .............................7-44
2. Removing .................................7-45
L. Lifter Drive Assembly ....................7-46
1. Construction .............................7-46
2. Removing .................................7-46
M. Cassette Pick-Up Drive
Assembly.......................................7-48
1. Construction .............................7-48
2. Removing .................................7-48
N. Attaching the Drive Belt.................7-50
O. DC Controller PCB........................7-51
1. Removing the DC Controller
PCB..........................................7-51
2. Points to Note When Replacing
the DC Controller PCB.............7-51
P. DC Power Supply Assembly .........7-52
1. Removing the DC Power
Supply Assembly......................7-52
Q. High-Voltage Transformer
Assembly.......................................7-53
1. Remove the High-Voltage
Transformer Assembly .............7-53
R. Power Supply Inlet Assembly........7-54
I. SIDE PAPER DECK...........................8-1
A. Inputs to and Outputs from the
Side Deck Driver ...........................8-1
1. Inputs to the Side Deck Driver
(1/2)..........................................8-1
2. Inputs to the Side Deck Driver
(2/2)..........................................8-2
3. Outputs from the Side Deck
Driver (1/1) ...............................8-3
B. Pick-Up..........................................8-4
1. Outline......................................8-4
2. Pick-Up Operation....................8-4
3. Sequence of Operations (deck
pick-up).....................................8-6
C. Detection of Paper for the Deck....8-7
1. Detecting the Presence/
Absence of Paper.....................8-7
2. Changing the Paper Size for
the Deck...................................8-7
D. Deck Lifter .....................................8-8
1. Lifter Operation.........................8-8
2. Detecting the Level of the
Stack in the Deck
(compartment)..........................8-10
E. Opening/Closing the Deck
(compartment)...............................8-11
1. Opening/Closing the Deck .......8-11
2. Sequence of Operations (deck
opening/closing) .......................8-12
F. Controlling the Deck Motor............8-13
1. Controlling the Deck Main
Motor (M101)............................8-13
2. Controlling the Deck Lifter
Motor (M102)............................8-15
II. DETECTING JAMS............................8-17
A. Outline...........................................8-17
1. When copy paper is present at
any of the sensors at power-on,
end of wait-up, or during
standby.....................................8-18
2. Deck Pick-Up/Vertical Path
Delay Jam ................................8-18
3. Deck Pick-Up/Vertical Path
Stationary Jam .........................8-18
III. DISASSEMBLY AND ASSEMBLY......8-19
A. External Covers.............................8-20
1. Removing the Front Cover.......8-21
2. Removing the Vertical Path
Cover (rear)..............................8-24
3. Removing the Right Cover.......8-25
4. Removing the Upper Cover......8-26
B. Paper Deck....................................8-28
1. Removing the Deck from the
Copier.......................................8-28
2. Removing the Compartment ....8-30
3. Changing the Deck Paper
Size ..........................................8-32
4. Adjusting the Deck Registration..8-33
CHAPTER 8 PAPER DECK-A1

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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5. Positioning the Roll ..................8-34
C. Drive System.................................8-35
1. Removing the Deck Pick-Up
Clutch (CL102).........................8-35
2. Removing the Deck Vertical
Path Clutch (CL101).................8-35
3. Removing the Deck Main
Motor (M101)............................8-36
4. Removing the Deck Lifter
Motor (M102)............................8-37
5. Removing the Lifter Cable
(deck front)...............................8-38
6. Removing the Lifter Cable
(deck rear)................................8-40
7. Routing the Lifter Cable ...........8-43
D. Feeding System ............................8-44
1. Removing the Deck Pick-Up
Unit...........................................8-44
2. Removing the Deck Pick-Up
Roller........................................8-45
3. Orientation of the Deck
Pick-Up Roller ..........................8-45
4. Removing the Deck Feeding
Roller........................................8-46
5. Orientation of the Deck
Feeding Roller..........................8-46
6. Removing the Deck Separation
Roller........................................8-47
7. Adjusting the Deck Separation
Roller Pressure.........................8-48
8. Positioning the Deck Pick-Up
Roller Releasing Solenoid
(SL101).....................................8-48
E. Electrical System...........................8-49
1. Removing the Side Deck
Driver PCB ...............................8-49
2. Removing the OPEN Switch
PCB..........................................8-49
I. SELECTING THE SITE......................9-1
II. UNPACKING AND INSTALLING........9-4
A. Unpacking......................................9-5
B. Installing the Scanner....................9-7
C. Installing the Fixing Assembly.......9-8
D. Installing the AP Kit and the
Charging Assemblies ....................9-10
E. Installing the Copy Tray.................9-16
1. Replacing the Delivery Gear....9-16
2. Replacing the Delivery Roller
Leaf Spring...............................9-17
F. Checking the Developing
Assembly.......................................9-18
G. Installing the Pick-Up Assembly....9-20
H. Supplying Toner.............................9-22
I. Connecting the PDF Connector ....9-26
J. Image/Function Checks and
User Mode.....................................9-27
III. RELOCATING THE MACHINE...........9-31
IV. INSTALLING THE CONTROL
CARD V..............................................9-32
V. INSTALLING THE COPY DATA
CONTROLLER-A1 .............................9-40
A. Setting the Board...........................9-40
B. Installing to the Copier ..................9-44
C. Checking the Operation.................9-46
VI. INSTALLING THE REMOTE
DIAGNOSTIC DEVICE II....................9-56
A. Installation to the Copier ...............9-56
CHAPTER 9 INSTALLATION
CHAPTER 10 MAINTENANCE AND SERVICING
I. PERIODICALLY REPLACED
PARTS..............................................10-1
II. CONSUMABLES AND DURABLES.10-2
A. Copier..........................................10-2
B. Paper Deck-A1............................10-3
III. SCHEDULED SERVICING TABLE ..10-4
IV. SCHEDULED SERVICING CHART.10-6
A. Copier..........................................10-6
B. Paper Deck-A1............................10-8

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CHAPTER 11 TROUBLESHOOTING
I. MAINTENANCE AND INSPECTION.11-3
A. Image Adjustment Basic
Procedure....................................11-3
B. Points to Note for Scheduled
Servicing......................................11-4
II. STANDARDS/ADJUSTMENTS........11-5
A. Image Adjustment .......................11-5
1. Adjusting the Image Leading
Edge Margin...........................11-5
2. Adjusting the Image Leading
Edge Non-Image Width
(registration)...........................11-5
3. Adjusting the Left/Right
Registration (left/right front
deck paper deck, cassette)....11-6
3-1. Adjusting the Left/Right
Registration (paper deck-A1)..11-7
4. Adjusting the Left/Right
Registration (holding tray
position; 2nd side of two-
sided/overlay copies) .............11-8
5. Adjusting the Left/Right
Margin ....................................11-8
6. Executing AE Automatic
Adjustment .............................11-9
7. Adjusting the AE Slope..........11-10
B. Exposure System........................11-11
1. Adjusting the Scanner Home
Position...................................11-11
2. Routing the Scanner Drive
Cable......................................11-12
3. Orientation of the Heat
Absorbing Glass.....................11-13
4. Adjusting the Tension of the
Scanning Lamp Cable............11-13
5. Adjusting the Position of the
Mirror......................................11-14
6. Cleaning the Mirror (No. 5
mirror).....................................11-15
7. Routing the Light-Blocking
Belt.........................................11-15
8. Routing the Lens X Direction
Drive Belt................................11-16
9. Adjusting the Position of the
Scanner Locking Solenoid
(SL1).......................................11-16
C. Image Formation System............11-17
1. Grid Wire of the Primary
Charging Assembly................11-17
2. Adjusting the Height of the
Charging Wire ........................11-19
3. Adjusting the Position of the
Blanking Exposure Lamp.......11-20
4. Position of the Roller
Electrode................................11-21
5. Adjusting the Position of the
Cleaning Assembly Side
Seal........................................11-21
6. Cleaning the Cleaner Side
Scraper...................................11-22
D. Pick-Up/Feeding System.............11-24
1. Orientation of the Cassette/
Front Paper Deck Pick-Up
Roller......................................11-24
2. Orientation of the Cassette/
Front Paper Deck Separation
Roller......................................11-25
3. Orientation of the Feeding
Roller (cassette/ front paper
deck).......................................11-25
4. Orientation of the Multifeeder
Pick-Up Roller ........................11-26
4-1. Orientation of the Paper
Deck-A1 Pick-Up Roller .........11-26
5. Rotation of the Multifeeder
Feeding Roller........................11-27
5-1. Orientation of the Paper
Deck-A1 Feeding Roller.........11-27
6. Adjusting the Separation
Roller Pressure of the
Cassette/Front Paper Deck....11-28
7. Adjusting the Separation
Roller Pressure of the
Holding Tray...........................11-29
8. Pick-Up/Feeding Roller of
the Multifeeder .......................11-29
9. Adjusting the Position of the
Pick-Up Roller Releasing
Solenoid (cassette) ................11-30
9-1. Adjusting the Position of the
Pick-Up Roller Releasing
Solenoid (front paper deck)....11-31
9-2. Adjusting the Position of the
Pick-Up Roller Releasing
Solenoid (paper deck-A1) ......11-31
10.Adjusting the Position of the
Pick-Up Roller Releasing
Solenoid (multifeeder)............11-32
11.Routing the Timing Belt of the
Side Guide (multifeeder
assembly)...............................11-33
12.Adjusting the Position of the
Solenoid (delivery paper
deflecting plate solenoid) .......11-33
13.Adjusting the Position of the
Holding Tray Paper Deflecting
Plate Drive Solenoid...............11-34
14.Adjusting the Position of the
Holding Tray Assembly Side
Guide Plate ............................11-34

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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15.Adjusting the Position of the
Holding Tray Paper Jogging
Plate.......................................11-35
16.Adjusting the Timing Belt of
the Holding Tray Paper
Jogging Guide Plate...............11-35
17.Adjusting the Position of the
Holding Tray Paper Jogging
Plate Solenoid........................11-36
18.Drive Belt................................11-36
E. Fixing System..............................11-38
1. Points to Note When Installing
the Fixing Heater....................11-38
2. Adjusting the Position of the
Fixing Assembly Inlet
Guide......................................11-38
3. Adjusting the Lower Roller
Pressure (nip).........................11-40
4. Adjusting the Fixing Clutch ....11-41
F. Electrical System.........................11-42
1. When Replacing the DC
Controller PCB.......................11-42
2. Checking the Surface
Potential Control System........11-42
3. Checking the Potential
System ...................................11-47
4. Potential Control System
Conversion Table ...................11-49
5. Checking the Environment
Sensor....................................11-54
6. Checking the
Photointerrupters....................11-55
7. Registering the Paper Width
Basic Value (
]4]; cassette/
multifeeder) ............................11-63
III. IMAGE FAULTS................................11-64
A. Initial Checks...............................11-64
1. Checking the Site
Environment...........................11-64
2. Checking the Originals...........11-64
3. Checking the Copyboard
Cover, Copyboard Glass, and
Standard White Plate.............11-65
4. Checking the Charging
Assemblies.............................11-65
5. Checking the Developing
Assembly................................11-65
6. Checking the Paper................11-65
7. Checking the Periodically
Replaced Parts.......................11-65
8. Others.....................................11-65
B. Sample Image Faults ..................11-68
C. Troubleshooting Image Faults.....11-69
1. The copy is too light
(halftone only). .......................11-69
2. The copy is too light (including
solid black).............................11-70
3. The copy is too light
(entire face)............................11-70
4. The copy has an uneven
density (darker at front)..........11-72
5. The copy has an uneven
density (lighter at front)..........11-72
6. The copy is foggy. (overall)....11-73
7. The copy has vertical
fogging....................................11-74
8. The copy has black lines
(vertical, fuzzy, thick)..............11-74
9. The copy has black lines
(vertical, fine)..........................11-75
10.The copy has white spots
(vertical)..................................11-76
11.The copy has white lines
(vertical)..................................11-76
12.The copy has white spots
(horizontal). ............................11-78
13.The copy has a soiled back...11-79
14.The copy has fixing faults. .....11-80
15., 16., 17. The copy has
displaced leading edge
registration.............................. 11-81
18.The copy is blurred and
fuzzy.......................................11-82
19.The copy has horizontal
fogging....................................11-83
20.The copy has poor
sharpness...............................11-83
21.The copy is blank...................11-84
22.The copy is solid black...........11-84
IV. TROUBLESHOOTING
MALFUNCTIONS.............................11-85
A. Troubleshooting Malfunctions .....11-85
1. E000.......................................11-85
2. E001.......................................11-86
3. E002.......................................11-87
4. E003.......................................11-87
5. E004.......................................11-87
6. E005.......................................11-88
7. E006.......................................11-88
8. E010.......................................11-88
9. E013.......................................11-89
10.E015.......................................11-90
11.E020.......................................11-91
12.E030 (The total copy counter
fails to turn on.)......................11-92
13.E031 (The option counter
has an open circuit.)...............11-92
14.E043 (paper deck-A1)............11-93
15.E050.......................................11-94
16.E051.......................................11-94
17.E202 (The keys on the
control panel are locked.).......11-95
18.E203.......................................11-95
19.E204 (The keys on the
control panel are locked.).......11-95
20.E210 (fault in lens X direction
drive system)..........................11-96

COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIMÉ AU JAPON)
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21.E212 (fault in lens Y direction
drive system)..........................11-96
22.E213.......................................11-96
23.E240.......................................11-96
24.E243.......................................11-97
25.E710/E711..............................11-97
26.E712.......................................11-97
27.E713.......................................11-97
28.E800.......................................11-98
29.E802.......................................11-98
30.AC power is absent................11-99
31.DC power supply is absent....11-100
32.Pick-up fails. (deck pick-up;
front paper deck + cassette)..11-101
33.The deck lifter fails to move up.
(front paper deck + cassette)..11-102
34.Pick-up fails. (cassette
pick-up)...................................11-103
35.The lifter fails to move up.
(cassette)................................11-105
36.Pick-up fails. (multifeeder)......11-106
37.The vertical path roller fails to
rotate......................................11-107
38.The registration roller fails to
rotate......................................11-107
39.The scanner fails to move
forward. ..................................11-108
40.The scanner fails to move in
reverse. ..................................11-108
41.The blanking exposure lamp
fails to turn on. .......................11-109
42.The pre-exposure lamp fails
to turn on................................11-109
43.The scanning lamp fails to
turn on....................................11-110
44.The hopper motor (M10) fails
to operate...............................11-111
45.The hopper motor (M11) fails
to operate...............................11-112
46.The drum heater fails to
operate...................................11-112
47.The lens fails to move............11-113
48.The Add Toner indicator fails
to turn on................................11-114
49.The Add Toner indicator fails
to turn off................................11-114
50.The Set Control Card
message fails to turn off.........11-115
51.The Set Control Card
message fails to turn off.........11-115
52.Jams occur at the fixing
assembly inlet. .......................11-115
53.The Add Paper message
fails to turn off.........................11-115
54.The fixing heater fails to
operate...................................11-116
55.Pick-up fails. (paper deck-A1)..11-117
56.The deck lifter fails to move
up. (paper deck-A1) ...............11-118
V. TROUBLESHOOTING FEEDING
PROBLEMS......................................11-119
A. Copy Paper Jams........................11-119
1. Pick-Up Assembly..................11-120
2. Separation/Feeding
Assembly................................11-121
3. Fixing/Delivery Assembly.......11-122
4. Fixing/Delivery Assembly
(reversed delivery) .................11-122
5. Cleaning Assembly ................11-123
6. Holding Tray Assembly (two-
sided/overlay copying, 1st
side)........................................11-123
7. Holding Tray Assembly
(re-pick up).............................11-124
8. Holding Tray Assembly
(overlay, re-pick up)................11-124
9. Holding Tray Feeding
Assembly................................11-125
B. Feeding Faults.............................11-126
1. Double Feeding......................11-126
2. Wrinkles..................................11-126
VI. ARRANGEMENT AND FUNCTIONS
OF ELECTRICAL PARTS ................11-127
A. Sensors.......................................11-128
B. Switches and Solenoids..............11-132
C. Motors and Fans.........................11-136
D. Clutches ......................................11-138
E. Lamps, Heaters, and
Photosensors ..............................11-140
F. PCBs ...........................................11-142
G. Paper Deck-A1............................11-144
1. Sensors and Switches............11-144
2. Motors, Clutches, Solenoids,
and PCBs...............................11-146
H. Variable Resistors (VR),
Light-Emitting Diodes (LED),
and Check Pins by PCB..............11-148
1. DC Controller PCB.................11-148
2. AC Driver PCB.......................11-151
3. DC Power Supply PCB..........11-151
4. Control CPU PCB...................11-152
5. Holding Tray Driver PCB........11-153
6. Potential Measurement PCB..11-154
7. HVT1 PCB..............................11-155
8. HVT2 PCB..............................11-156
9. Inverter PCB...........................11-156
10.Lamp Regulator PCB.............11-157
11.Counter PCB..........................11-157
12.Side Deck Driver
(paper deck-A1) .....................11-158
VII. SERVICE MODE..............................11-159
A. Outline.........................................11-159
B. Using Service Mode....................11-160
C. Using Adjustment Mode and
Options Mode..............................11-160
D. Display Mode ( )...............11-162
E. I/O Display Mode ( ).........11-179
F. Adjustment Mode ( ).........11-215
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APPENDIX
A. GENERAL TIMING CHART..........A-1
B. SIGNALS AND ABBREVIATIONS ...A-3
1. Signals......................................A-3
2. Abbreviations............................A-4
C. GENERAL CIRCUIT DIAGRAM....A-5
not available
D. PAPER DECK-A1 GENERAL
CIRCUIT DIAGRAM......................A-7
E. SPECIAL TOOLS LIST .................A-9
F. SOLVENTS AND OILS..................A-10
G. Function Mode ( ).............11-233
H. Options Mode ( )...............11-244
I. Counter Mode ( )..............11-253
VIII. SELF DIAGNOSIS ...........................11-259
A. Copier..........................................11-259
B. RDF-D1 .......................................11-264
C. Sorter...........................................11-266
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COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 1
GENERAL DESCRIPTION
I. FEATURES.........................................1-1
II. SPECIFICATIONS..............................1-2
A. Copier............................................1-2
B. Paper Deck-A1..............................1-9
III. NAMES OF PARTS............................1-10
A. External View.................................1-10
B. Cross Section................................1-12
IV. OPERATING THE MACHINE.............1-13
A. Control Panel.................................1-13
B. Extended Modes ...........................1-14
C. User Mode.....................................1-15
V. ROUTINE MAINTENANCE BY THE
USER..................................................1-19
VI. POINTS TO NOTE (BY THE USER)..1-19
VII. IMAGE FORMATION..........................1-20
A. Outline...........................................1-20
This chapter introduces the copier’s features and specifications, shows how to operate the copier, and
explains how copies are made.

I. FEATURES
1. It offers 50-sheet copying (A4, horizontal) and 60-sheet copying (A4, horizontal; 1
original) using the RDF’s stream reading.
2. It has a reduced rate of jamming, thanks to new pick-up and feeding mechanisms.
3 It promises to produce high-quality copies for a long time, which is a prerequisite for
all high-speed copiers.
The use of Canon’s proprietary A-Si (amorphous silicon) photosensitive drum
ensures durability, while its single-component toner projection developing
mechanism leads to enhanced image reproduction.
4. It comes with a large-size liquid crystal display for ease of viewing.
5. When fitted with a side paper deck (accessory), it will hold as many as 7,550 sheets
(5,550 sheets if NP6250).
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV.0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 1 GENERAL DESCRIPTION
1-1