Canon NP6320 Service Handbook

REVISION 0

DEC. 1999

FY8-23B8-000

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 INFORMA TION CONTAINED HEREIN SHOULD BE DIRECTED TO THE COPIER SERVICE DEPARTMENT OF THE SALES COMPANY. THIS DOCUMENT ATION IS INTENDED FOR ALL SALES AREAS, AND MA Y CONTAIN INFORMATION NOT APPLICABLE TO CERTAIN AREAS.

Printed in Japan

Imprimé au Japon

Use of this manual should be strictly supervised to avoid disclosure of confidential information.

Prepared by

OFFICE IMAGING PR ODUCTS TECHNICAL SUPPORT DIVISION

OFFICE IMAGING PR ODUCTS QUALITY ASSURANCE CENTER

CANON INC.

5-1, Hakusan 7-chome, Toride-shi, Ibaraki 302-8501 Japan

Reading the Troubleshooting Tables

The troubleshooting tables used in this chapter are modifications of the general servicing flowchart. The example below shows how to read the tables.

Example: AC power is not supplied.

Cause

Power cord Doors

Step

Checks

Is the power cord plugged in? Are the front door and copy delivery door closed properly?

YES/

NO NO

Plug the copier in. Make sure the doors are closed properly.

Action

• To find possible causes of trouble, refer to the “Cause” column in the table. For example, for “AC power is not supplied,” shown above, the possible causes include the following: power cord, power cord, and door switches.

• To find the repair or check procedure for a certain type of problem, go through the table step by step. Depending on the answer to the “Check” question, perform the action described in the “Action” column, or continue to the next step.

Step Check Result Action

Is the power cord plugged in?

Plug the copier in.

YES

Are the doors closed properly?

YES

Make sure the doors are closed properly.

• Included among the voltage checks to be performed using a meter is “Measure the voltage between J109-1 (+) and J109-2 (-) on the DC controller PCB.” Here, the (+) and (-) signs after the connector number indicate the polarity of the meter leads that are to be connected to the connectors. Example: J109- 1(+) Positive lead

J109- 2(-) Negative lead

CHAPTER 1 MAINTENANCE AND INSPECTION

A. Periodic Servicing Inspection.......1-1

B. Per iodically Replaced Par ts .........1-2

C. Durable Parts ............................... 1-3

CHAPTER 2 STANDARDS AND ADJUSTMENTS

A. Mechanical................................... 2-1

CHAPTER 3 FUNCTION AND ARRANGEMENT OF

THE ELECTRICAL PARTS

A. Sensors, Fuses and Lamps ......... 3-1

B. Clutches, Solenoids, Fans,

Motors and Heaters .....................3-2

D. Basic Image Adjustment

Procedure .....................................1-5

E. Per iodic Maintenance

Check points ................................1-6

B. Electrical ................................... 2-15

C. Switches, Cricuit Breakers,

Counters, Etc. ..............................3-3

D. PCBs ............................................ 3-4

CHAPTER 4 IMAGE TROUBLESHOOTING

A. Initial Check..................................4-1

B. Sampels of Image Faults .............4-4

CHAPTER 5 OPERATION TROUBLESHOOTING

A. Troubleshooting of Malfunction ....5-1

CHAPTER 6 TROUBLESHOOTING THE FEEDING

PROBLEMS

A. Paper Jams .................................. 6-1 B. Incorrect Paper Feed Operation ..6-5

C. Troubleshooting of Image Faults..4-5

iii

CHAPTER 7 SERVICE MODE

A. Outline..........................................7-1

B. Using the Service Mode..............7-1

CHAPTER 8 SELF DIAGNOSIS

A. Self Diagnosis ..............................8-1

APPENDIX

A. General Timing Chart.................. A-1

B. List of Signals/Commands .......... A-3

C. Guide to Service Mode ................7-2

C. General Circuit Diagram .............A-5

D. Specifications.............................. A-7

CHAPTER 1 MAINTENANCE AND INSPECTION

A. Periodic Servicing Inspection

Note:

Do not use solvents or oils other than those specified.

∆: Clean l: Replace ×: Lubricate o: Adjust : Check

Periodic servicing

Unit

External

Scanner drive unit

Feeder

Optical path

Corona assemblies

Developing assembly Fixing assembly

Drum unit

Description

Copyboard glass Ozone filter Dustproofing filter Scanner rails

Transfer guide Feeder belt Feeder frame Scanning lamp reflector Scanning lamp side reflector Mirrors 1 to 6 Lens Dustproofing glass Primary corona assembly Primary corona wire Transfer corona assembly Transfer corona wire Static charge eliminator Developing rollers (front and rear) Upper fixing roller Lower fixing roller Paper guide plate Separation claws (upper and lower) Lower face of drum unit Coupling pin

Every

15,000

copies*

∆

∆ ∆ ∆

∆ ∆ ∆ ∆

∆ ∆

∆ ∆ ∆ ∆

∆ ∆

Every

30,000

copies

∆ ∆

∆

Every

60,000

copies

Every

90,000

copies

Clean with alcohol. or 1 year or 1 year Clean with alcohol; then apply high-viscosity lubricating oil (TKN-0451). Damp cloth

Clean with a blower brush. If excessively solid, clean with alcohol. Clean mirrors 5 and 6 with the mirror cleaning tool. Dry wipe using lint-free paper; then clean using alcohol.

Clean with a brush. Clean with alcohol.

Clean with cleaning oil. Clean with solvent.

Remarks

* Items to be cleaned every 15,000 copies or every 6 months, whichever comes first.

Table 1-1

1-1

CHAPTER 1 MAINTENANCE AND INSPECTION

B. Periodically Replaced Parts

To maintain the copier at its peak performance, the parts listed in the following chart must be replaced periodically. Although the deterioration of a part may not be visible, it can seriously hamper the performance of the copier if not replaced on schedule.

Parts should be replaced during the regular service visit that is closest to the end of the service life of the part.

as of Dec. 1999

No.

1 2 3 4

Description

Ozone filter Dustproofing filter Static charge eliminator Transfer corona wire

Part No.

FF2-5595-00P

FA0-0339-00P

FF1-9438-070

FY3-0040-000

Quantity

1 1 1

Replacement

60,000 60,000 60,000 60,000

Table 1-2

Note:

The above values are estimates and are subject to change based on future data.

Remarks

or 1 year or 1 year

1-2

CHAPTER 1 MAINTENANCE AND INSPECTION

C. Durable Parts

The values shown in the table below indicate the expected average life (number of copies) of parts which may require replacement at least once during the warranty period due to deterioration or damage but which can be simply replaced to restore the performance of the copier.

as of Dec. 1999

Service life

No.

2 3

4 5 6 7

11 13 14 15

Description

Paper pick-up roller (pick-up assembly) Multi-feeder roller Pad (multi feeder)

Scanner drive cable Scanning lamp (scanner) Pre-exposure lamp Upper fixing roller (fixing assembly) Upper separation claw (fixing assembly) Lower separation claw (fixing assembly) Lower fixing roller (fixing assembly) Thermistor assembly Fixing roller bushing Developing assembly Oil applying roller

Part No.

FA0-0241-00P

FC1-0741-00P FC1-0736-00P

FF0-0041-00P FH7-3114-000 FG2-4048-00P FC2-9961-00P

FB1-0301-000

FA2-9037-000

FC2-8962-00P

FF3-2855-00P

FS1-1240-00 FG3-0351-00P FA0-0711-00P

Quantity

1 1

1 1 1 1

1 2 1 1

(number of

copies)

100,000

100,000 100,000

120,000 100,000 200,000 200,000

200,000

100,000 200,000 300,000 60,000

Remarks

Must be replaced at the same time

Table 1-3

Note:

The above values are estimates and are subject to change based on future data.

1-3

D. Basic Image Adjustment Procedure

Image adjustment should be performed using the following settings:

1. Manual (non AE) exposure

2. Density cursor setting : 5

3. Direct reproduction ratio

Making pre-Checks

Clean the corona wires.

Make the following copies (using test sheet NA-2 or NA-3): Copy density 5: 2 copies Copy density 1: 1 copy

Check the following :

1. Differences in density between the near and far sides of the copies.

2. Density of gray scale No. 10. (No. 9, if NA-3)

3. Fogging in blank areas.

Adjust the image by the following procedure when the photosensitive drum has been replaced.

Make this adjustment with the upper front panel and front door installed.

Adjusting Side-to-Side Density

Is there a

difference in density

on the near and far sides

of the copies?

YES

Is there a

difference in density

in the image area of a

reduced copy?

YES

Check for stains on the scanning lamp, reflector plate, and mirror; clean them if necessary.

Is the

distance be-

tween the primary

corona grid and the photo-

sensitive drum

correct?

(Note 1)

YES

Adjusting the Density

Is the

density of gray

scale No. 10 correct?

(See Note 3.)

Is the

density of gray

scale No. 10 too dark?

(See Note 3.)

Turn the copy density knob counterclockwise. (Note 2) (The image will become darker.)

YES

Turn the copy density knob clockwise. (Note 3) (The image will become lighter.)

End.

(See Note 4.)

Is the top

margin of the copy

at copy density 1 within

the standard?

Adjust Service mode (C03). (See p. 10-3.)

Return copy density to 5.

YES

Make one copy.

Replace the grid plate and grid mounting panel.

Mount the drum unit and make one copy.

Replace the drum unit.

Note 1 : The distance between the grid and

Note 2 :

Figure 1-1

Make one copy.

photosensitive drum is determined by the spacer mounted on the grid. Check for deterioration or damage to the spacer.

This changes the developing bias, but not the intensity of the scanning lamp.

Note 3 :

Note 4 :

No. 10 (No. 9, if NA-3) on the gray scale of a copy should have the density of No. 8 on the gray scale of the test sheet.

Turning the copy density knob clockwise too far past the proper position will result in fogging in blank areas.

1-5

E. Periodic Maintenance Check points

Copyboard/Scanner

Location

Copyboard glass

Reflectors Mirrors 1, 2 and

Tool/Cleaner

Alcohol

Blower brush

Blower brush or alcohol and lint-free paper

Action/Remarks

Cleaning Cleaning

Clean with a blower brush. If dirt cannot be removed with a blower brush, clean with alcohol.

Fixing assembly and Paper pick-up assembly

Optical path

Location

Lens Dust-proofing

glass

Mirror 4, 5 and 6

Blower brush or alcohol and lint-free paper

Mirror cleaning tool

Corona assemblies

Location

Developing rolls

Primary corona assembly

Transfer corona assembly

Alcohol

Alcohol and lint-free paper

Tool/Cleaner

Action/Remarks

Clean with a blower brush. If dirt cannot be removed with a blower brush, clean with alcohol.

Cleaning

Action/Remarks

Cleaning

Wipe with a dry cloth; then, clean with lint-free paper moistened with alcohol.

Location

Separation claws Upper fixing

roller, lower fixing roller

Paper guide plate

Tool/Cleaner

MEK

Cleaning oil (TKN-0464)

MEK Cleaning

Action/Remarks

Cleaning Cleaning

Static charge ellminator

Primary corona grid

Blower brush

Cleaning

Separation and Transfer assemblies

Location

Transter guide Feeder belt,

Feeder assembly

Tool/Cleaner

Damp cloth

Action/Remarks

Cleaning

1-6

Figure 1-2

CHAPTER 2 STANDARDS AND ADJUSTMENTS

A. Mechanical

1. Leading Edge Non-Reproduced Area

There is a white strip on the bottom of the copyboard glass in the position shown in the figure below. If bias is being applied to the grid of the primary corona while the scanner is passing the white strip, the leading edge of the copy will be reproduced blank. If the leading edge non-image width is outside the standards, adjust the timing at which the grid bias goes from OFF to ON in the service mode (C03).

White strip

Surface of copyboard glass

Approx. 10 mm

Figure 2-1

The standard leading edge nonreproduced area on a Direct copy of the test sheet is 2.0 ±1.5 mm.

2.0 ±1.5 mm

Figure 2-2

A higher setting (C03) increases the leading edge non-image width; in units of 0.25 mm.

2-1

CHAPTER 2 STANDARDS AND ADJUSTMENTS

2. Leading Edge Registration

Make adjustments in the service mode (C02) so that the distance shown is 10.0 ±1.5 mm when

the test sheet is copied in Direct.

Note:

Adjust the leading edge non-reproduced area before making this adjustment.

10.0 ±1.5 mm

Figure 2-3

A higher setting in the service mode (C02) increases the leading edge margin.

3. Side-to-Side Registration

The standard near side registration on a Direct copy of the test sheet is 10.0 ±2 mm.

0 2

4 6

10 ±2 mm

Figure 2-4

Loosen the two screws, and adjust the latch assembly for the cassette found on the back of the

bottom plate by sliding it.

Screws

Feeder release lever

2-2

Cover

Figure 2-5

CHAPTER 2 STANDARDS AND ADJUSTMENTS

4. Installing the Lens Drive Cable

This unit has been accurately adjusted at the factory with special gauges. Do not remove parts other than those shown below, nor loosen any other screws.

[2]

Lens pulley

[3]

Lens pulley fixing plate

4 turns

[4]

Pulley mount

Mark with scriber.

Mounting screws

[5]

Cable mount

Mark with scriber

[1]

Figure 2-6

a. Removing the Lens Wire

1) Unscrew the three screws; then remove the upper frame.

2) Mark the positions of the pulley fixing base and the wire fixing with a scriber.

3) Unscrew the two screws used to hold the pulley fixing base.

4) Remove the wire.

b. Attaching the Lens Wire

1) Unscrew the two screws used to hold the lens pulley fixing plate, and remove the lens pulley.

(See Figure 2-6.)

2) Wind the lens wire around the lens pulley as shown in Figure 2-6, and fix it with the two fixing

screws.

3) Shift the pulley fixing base to the position of the scriber mark; then fix it with the two fixing

screws.

2-3

CHAPTER 2 STANDARDS AND ADJUSTMENTS

5. Installing the Scanner Drive Cable

Top groove of the pulley

[6]

Under groove of the pulley

[1]

Pulley 2

Screw B

Screw A

[3]

Mark the position

4 turns

pulley 1

[2]

Under groove of the pulley

Scanner pulley [4]

pulley 3

[5]

Top groove of the pulley

(rear)

2-4

Figure 2-7

CHAPTER 2 STANDARDS AND ADJUSTMENTS

6. Adjusting the Tension of the Scanner Drive Cable

Move the mirror 1 mount to the home position (start position). As shown in Figure 2-8, pull at point [A] (approximate center) of the free cable with a spring gauge so that the wires touch each other. If the reading on the spring balance is not about 1.0±0.5 kg, turn screw A of Figure 2-7 to achieve this reading.

1.0+0.5 kg

Pulley 2

Scanner drive capstan

Figure 2-8 Top View

[A]

Scanner

Mirror

2 and 3

mount

Pulley1

Pulley3

2-5

CHAPTER 2 STANDARDS AND ADJUSTMENTS

7. Adjusting the Position of the Mirrors (length of optical path between mirrors 1 and 2)

Adjust the tension of the scanner drive cable before making this adjustment. Adjust the position of the scanner (mirror 1) by altering the tension of the scanner drive cable. (Loosen the cap screws.)

Reference:

1. The cable will stretch after a large number of copies have been made, making readjustment

necessary.

2. An incorrect distance between mirror 1 and mirror 2 will cause an incorrect side-to-side repro-

duction ratio and poor focus, resulting in poor sharpness and fuzziness in the copy image.

1) Mark a line 10 mm from each edge of a piece of copy paper (B4), as shown in Figure 2-9.

10 mm 10 mm

Lines

Figure 2-9

2) Make a copy of the paper with the lines marked on it. (A)

3) Place a blank sheet of paper on the copyboard and feed the marked sheet of paper into the

copier. (Use manual feed.) (B)

• Passing the sheet through the copier indicates the amount of shrinkage caused by heat.

4) Align the lines on the left side of the copy sheet (A) and the sheet passed through the copier (B).

If the lines on the right are not in line, adjust the position of the scanner so that dimensions x

and y are equal.

Sheet A

Sheet B

Figure 2-10

x=y Correct x>y Move the scanner in direction [a] (Figure 2-11). x<y Move the scanner in direction [b] (Figure 2-11).

2-6

CHAPTER 2 STANDARDS AND ADJUSTMENTS

Reference:

If the distance between the mirrors is short, the image will be enlarged. If the distance is long,

the image will be reduced.

No.1 mirror mount

[a] [b]

Mirror drive cable

(front)

(rear)

Fixing screws

Figure 2-11 Top View

2-7

CHAPTER 2 STANDARDS AND ADJUSTMENTS

8. Mounting the Main Motor

The drive of the main motor is used to drive the drum and execute pick-up operations by way of timing belts.

Adjust the tension of the belt by selecting the mounting hole of the main motor so that when the center of the timing belt is pushed down with a force of 500 g, the distance between the two runs of the belt is between 20 and 25 mm.

Main motor

mounting holes Tension increases

500 g

Tension decreases

Drum drive unit

Belt 1

Dimension 20 to 25 mm

Main motor

Figure 2-12

To adjust the timing belt used to execute pick-up operations, on the other hand, push the pulley

support plate with a force of 2.4 kg, and fix it in place when it stops; see Figure 2-13.

Belt 2

Pick-up drive unit

Adjusting screws

Pulley support plate

2.4 kg

Main motor

2-8

Figure 2-13

CHAPTER 2 STANDARDS AND ADJUSTMENTS

9. Installation Position of the Transfer Guide

When installing the transfer guide, ensure that the clearance between the transfer assembly

roller and the photosensitive drum is about 1.8 ± 0.2 mm, as shown in Figure 2-14.

Photosensitive drum

Lower transfer guide

1.8 ± 0.2 mm

Transfer assembly roller

Figure 2-14

10. Installation Position of the Scanner Drive Assembly

Loosen the four screws of the scanner drive assembly; then while pushing the scanner drive assembly against the rear plate (direction of arrow [1]) move it in the direction of the manual feed tray (direction of arrow [2]) so that it touches the pulley base and the lens gear. In this condition, tighten the screws; then, confirm that there is play between the lens gear and the gear of the lens drive capstan.

Pulley base

[1]

Pulley gear

[2]

Lens base

Lens gear Shaft

Scanner drive assembly

Figure 2-15

2-9

CHAPTER 2 STANDARDS AND ADJUSTMENTS

11. Installing the Corona Wires in the Primary and Transfer Corona Assemblies

Primary corona assembly

(about 2 mm)

Transfer corona assembly

(about 5 mm)

Figure 2-16

• The corona wire must not be bent or twisted, and the gold plating must not be peeling off.

• The corona wire must not be slack. (The length of the corona wire tension spring should be about 12 mm.)

• The corona wire must be in the V groove of the height adjusting piece.

12. Adjusting the Height of the Corona Wires

Corona assembly

Primary corona assembly

Transfer corona assembly

Standard position

Approx. 10.5 mm

Approx. 10 mm

Allowable range

±2 mm

Figure 2-17

Note:

The height (position) of the corona wire of the primary and transfer corona assemblies can be adjusted by turning the screw at the back of the corona wire. Turning the screw once causes the height of the corona wire to change by about 0.7 mm.

2-10

CHAPTER 2 STANDARDS AND ADJUSTMENTS

13. Installation Position of Side Seals

1) Clean the surface on which the side magnetic seal will be hooked using alcohol.

2) Fix the side magnetic seal at the position shown in Figure 2-19.

Note:

Put the hook of the magnetic side seal on its side on the plastic marking so that the magnetic side seals is firmly in the correct position.

Blade

Magnetic side seal

Screw hole

Figure 2-18

Sponge

Butted.

Magnetic side seal

Magnetic cylinder

Figure 2-19

2-11

CHAPTER 2 STANDARDS AND ADJUSTMENTS

14. Adjusting the Fixing Assembly Roller Pressure (adjusting the nip width)

The nip width should conform to the dimension shown in Table 2-1. Adjust the nip width with

the bolt when it is out of standard.

Direction of feed

A3 size

baCenter of

copy paper

Figure 2-20

Note:

a and c are the dimensions of the 10 mm position at both edges of the copy paper.

Dimension

|a-c|

Measure after the upper and lower rollers have been adequately heated.

4.0 ±0.5 mm

0.5 mm or less

Table 2-1

• Measuring the Nip Width

If the rollers are cool, leave the copier ON, keep the Wait indicator ON for 15 minutes; make 20 copies, and then measure the nip width.

Measuring Procedure

1) Open the copyboard cover and make an A3 size solid black copy.

2) Set the solid black copy to the multifeeder.

3) Select the service mode C13. 3-1) Detach the VR cover from the rear of the left cover. 3-2) Press the service switch (SW300) on the DC controller PCB. 3-3) Select the service mode C13 using the 10-key or the zoom key.

4) Press the Sort/Group key.

• The solid black paper is automatically picked up from the multifeeder.

• Then the solid black paper is stopped at the fixing roller and, after a specific period, is delivered.

5) Measure the width of the toner portion which has a glossy surface, as shown in Figure 2-20.

6) Press the service switch (SW300) to exit from the service mode.

2-12

CHAPTER 2 STANDARDS AND ADJUSTMENTS

15. Cassette Spring Strength

If the strength of the springs in the cassette that raise the paper-lifting plate is not correct,

improper paper pick-up or other problem will result.

If such a problem occurs, check the spring strength with a compression spring scale.

Press the scale at point A shown in Figure 2-21 to push the plate down 3 mm and read the scale. If the indication is outside the range shown in Table 2-2, replace both springs. (The springs cannot be adjusted.)

Hook

Cassette

Center plate

25 mm

Hook

Figure 2-21

Cassette size Indication on spring scale A3 and LGR cassette 390 ±30g A4R and LTR-R cassette 350 ±20g STMT 330 ±40g

Table 2-2

2-13

CHAPTER 2 STANDARDS AND ADJUSTMENTS

16. Degree of Arching (multifeeder)

Make the following adjustments if the copy paper picked up from the multifeeder moves askew or wrinkles are noted on the leading edge of the copy paper; the adjustments are made by changing the degree of arching of the copy paper between the multifeeder pick-up roller and the registration roller.

1) Set 50 sheets of A4 paper (80 g/m2) on the multifeeder tray.

2) Press the Paper Select key on the control panel to select the multifeeder.

3) Press the Copy Start key.

4) Check that the leading edge of the copy paper butts against the registration roller and arches; at

the time, turn the copier OFF.

5) Measure the distance between [A] (trailing edge of the second sheet) and [B] (trailing edge of

the first sheet).

Registration roller

Arching

70 to 75 mm

[B]

Multifeeder roller

[A]

Figure 2-22

6) Turn the copier ON, and select C04 in the service mode.

7) Enter a setting so that the measurement between [A] and [B] (step 5)) is between 70 and 75

mm.

Note:

A higher setting increases the measurement, i.e., the multifeeder clutch OFF timing is delayed (in units of 0.25 mm).

2-14

CHAPTER 2 STANDARDS AND ADJUSTMENTS

B. Electrical

1. List of PCBs/VRs/LEDs/Check Pins

Variable resistors, LEDs and check pins which are used for adjustments in the field are listed

below.

VRs and check pins not listed here are used only for factory adjustments which require special tools and measuring instruments, as well as great care and precision. Do not attempt to adjust such parts.

Notes:

1. Leakage current may flow through some LEDs and cause them to glow dimly even though they are supposed to be OFF.

2. VRs which can be adjusted in the field .................

VRs which should not be adjusted in the field......

a. DC Controller PCB

J306

J305

J304

J303

J324

J302

J301

J307

J308

J323J309 J310

J312 J311 J313

J314

J315

J316

J317

SW300 VR301

J318

J320J321 J319

Figure 2-23

VR No

VR301

SW No

SW300

Purpose

Adjusting AE reference point

Table 2-3

Purpose

Press to enter or leave the SERVICE mode.

Table 2-4

2-15

CHAPTER 2 STANDARDS AND ADJUSTMENTS

b. Lamp driver PCB

J204

VR No

VR202

J201

VR202

Figure 2-24

Lamp intensity adjustment

Table 2-5

J202

J203

Purpose

2-16

CHAPTER 2 STANDARDS AND ADJUSTMENTS

2. AE Adjustment

Make the following adjustments when the AE sensor or the DC controller PCB has been re-

placed.

1) Remove the VR cover at the back of the left cover.

2) Set the power switch ON.

• Wait until the wait period has ended.

3) Place an NB-3 or NA-2, NA-3 test sheet on the copyboard, and lower the copyboard cover.

4) Press switch SW300 on the DC controller PCB.

• ‘C00’ will appear on the Copy Count/Ratio indicator on the control panel.

• If ‘C00’ does not appear, press the “0” number key on the control panel so that ‘C00’ appears.

5) Press the Sort/Group key on the control panel.

• The scanner will move forward to the AE measuring position; then, the scanning lamp will go ON. (Note)

6) Adjust VR301 on the DC controller so that “20” appears on the Copy Count/Ratio indicator.

For reference:

7.7

Copy density

VR301

Test sheet Sheet of newspaper

Document density

Figure 2-25

7) Press the Sort/Group key.

• The scanning lamp will go OFF, and the scanner will return to the home position.

8) Remove the test sheet, place a sheet of newspaper on the copyboard, and lower the copyboard cover.

9) Press the Sort/Group key.

• The copier will perform the same operations as described in step 5).

10) Make a note of the numerical value displayed on the Copy Count/Ratio indicator.

11) Press the Sort/Group key.

• ‘C00’ will appear on the Copy Count/Ratio indicator.

12) Press the “1” number key.

• ‘C01’ will appear on the Copy Count/Ratio indicator.

13) Enter the value recorded in step 10) using the numeric keypad.

7.7

Copy density

Test sheet Sheet of newspaper

Document density

When the setting is lowered. When the setting is raised.

Figure 2-26

2-17

+ 67 hidden pages

Canon NP6320 Service Handbook

CONTENTS

A. Periodic Servicing Inspection

B. Periodically Replaced Parts

C. Durable Parts

D. Basic Image Adjustment Procedure

E. Periodic Maintenance Check points

A. Mechanical

B. Electrical