Konica Minolta AD-723 User Manual

SERVICE MANUAL

Model

AD-723

FEBRUARY 1999

CSM-AD723

KONICA BUSINESS TECHNOLOGIES, INC.

AD-723

SERVICE MANUAL

FEBRUARY 1999

Used on Konica Model

7823

IMPORTANT NOTICE

Because of the possible hazards to an inexperienced person servicing this equipment, as well as the risk of damage to the equipment, Konica Business Technologies strongly recommends that all servicing be performed by Konica-trained service technicians only.

Changes may have been made to this equipment to improve its performance after this service manual was printed. Accordingly, Konica Business Technologies, Inc., makes no representations or warranties, either expressed or implied, that the information contained in this service manual is complete or accurate. It is understood that the user of this manual must assume all risks or personal injury and/or damage to the equipment while servicing the equipment for which this service manual is intended.

Corporate Publications Department

Printed in U.S.A.

GENERAL, MECHANICAL/ELECTRICAL

1. SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-1

2. PARTS IDENTIFICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-2

3. CROSS-SECTIONAL VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-3

4. DRIVE SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-4

5. ELECTRICAL COMPONENTS LAYOUT. . . . . . . . . . . . . . . . . . . . M-5

6. DESCRIPTION OF EACH MECHANISM AND CONTROL

6-1. Exit/Turnover Switching Mechanism . . . . . . . . . . . . . . . . . . . M-6

6-2. Fuser Oil Cleaning Mechanism. . . . . . . . . . . . . . . . . . . . . . . . M-7

6-3. Paper Standby Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-7

6-4. Switchback Operation (Turnover). . . . . . . . . . . . . . . . . . . . . . M-8

7. OPERATION AND CONTROL

7-1. No. of Multiple 2-Sided Copies . . . . . . . . . . . . . . . . . . . . . . . . M-9

7-2. Sensor Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-9

7-3. 2-Sided Copying Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . M-10

DIS/REASSEMBLY, ADJUSTMENT

1. DISASSEMBLY

1-1. Removal of the Exterior Covers and Guides . . . . . . . . . . . . . D-1

1-2. Removal of Vertical Transport Clutch CL1. . . . . . . . . . . . . . . D-2

1-3. Removal of the Vertical Transport Roller (Metallic One) . . . D-3

1-4. Removal of the Vertical Transport Roller (Rubber One). . . . D-3

1-5. Removal of the Turnover Entrance Guide . . . . . . . . . . . . . . . D-4

2. ADJUSTMENTS

2-1. Adjustment of Dup. Left-Margin . . . . . . . . . . . . . . . . . . . . . . . D-4

2-2. Adjustment of Exit/Turnover Switching Solenoid SL1. . . . . . D-5

TROUBLESHOOTING

1. MISFEED DETECTION

1-1. Misfeed Detection Conditions . . . . . . . . . . . . . . . . . . . . . . . . . T-1

1-2. Misfeed Troubleshooting Procedures. . . . . . . . . . . . . . . . . . . T-2

APPENDED DIAGRAMS

◆ELECTRICAL WIRING DIAGRAM / ELECTRICAL CIRCUIT DIAGRAM

iii

SAFETY PRECAUTIONS

Installation Environment

Safety considerations usually are directed toward machine design and the possibility of human error. In addition, the environment in which a machine is operated must not be overlooked as a potential safety hazard.

Most electrical equipment is safe when installed in a normal environment. However, if the environment is different from what most people consider to be normal, it is conceivable that the combination of the machine and the room air could present a hazardous combination. This is because heat (such as from fusing units) and electrical arcs (which can occur inside switches) have the ability to ignite flammable substances, including air.

When installing a machine, check to see if there is anything nearby which suggests that a poten-

tial hazard might exist. For example, a laboratory

might use organic compounds which, when they evaporate, make the room air volatile. Potentially dangerous conditions might be seen or smelled. The

presence of substances such as cleaners, paint thinners, gasoline, alcohol, solvents, explosives, or similar items should be cause for concern.

If conditions such as these exist, take appropriate action, such as one of the following suggestions.

effect may be caused by altering any aspect of the machine’s design. Such changes have the potential of degrading product performance and reducing safety margins.

For these reasons, installation of any modification not

specifically authorized by Konica Business Machines U.S.A., Inc., is strictly prohibited.

The following list of prohibited actions is not all-inclusive, but demonstrates the intent of this policy.

• Using an extension cord or any unauthorized power cord adapter.

• Installing any fuse whose rating and physical size differs from that originally installed.

• Using wire, paper clips, solder, etc., to replace or eliminate any fuse (including temperature fuses).

• Removing (except for replacement) any air filter.

• Defeating the operation of relays by any means

(such as wedging paper between contacts).

• Causing the machine to operate in a fashion other than as it was designed.

• Making any change which might have a chance of defeating built-in safety features.

• Using any unspecified replacement parts.

• Determine that the environment is controlled

(such as through the use of an exhaust hood) so that an offending substance or its fumes cannot reach the machine.

• Remove the offending substance.

• Install the machine in a different location.

The specific remedy will vary from site to site, but the principles remain the same. To avoid the risk of injury or damage, be alert for changes in the environment when performing subsequent service on any machine, and take appropriate action.

Unauthorized Modifications

Konica copiers have gained a reputation for being reliable products. This has been attained by a combination of outstanding design and a knowledgeable service force.

The design of the copier is extremely important. It is the design process that determines tolerances and safety margins for mechanical, electrical, and electronic aspects. It is not reasonable to expect individuals not involved in product engineering to know what

General Safety Guidelines

This copier has been examined in accordance with the laws pertaining to various product safety regulations prior to leaving the manufacturing facility to protect the operators and service personnel from injury. However, as with any operating device, components will break down through the wear-and-tear of everyday use, as will additional safety discrepancies be discovered. For this reason, it is important that the technician periodically performs safety checks on the copier to maintain optimum reliability and safety.

The following checks, not all-inclusive, should be made during each service call:

CAUTION: Avoid injury. Ensure that the copier is disconnected from its power source before continuing.

• Look for sharp edges, burrs, and damage on all external covers and copier frame.

• Inspect all cover hinges for wear (loose or broken).

• Inspect cables for wear, frays, or pinched areas.

SAFETY PRECAUTIONS

• Ensure that the power cord insulation is not damaged (no exposed electrical conductors).

• Ensure that the power cord is properly mounted to the frame by cord clamps.

• Check the continuity from the round lug (GND) of the power cord to the frame of the copier -- ensure continuity. An improperly grounded machine can cause an electrically-charged machine frame.

Safeguards During Service Calls

Confirm that all screws, parts, and wiring which are removed during maintenance are installed in their original positions.

• When disconnecting connectors, do not pull the wiring, particularly on AC line wiring and high voltage parts.

• Do not route the power cord where it is likely to be stepped on or crushed.

• Carefully remove all toner and dirt adhering to any electrical units or electrodes.

• After part replacement or repair work, route the wiring in such a way that it does not contact any burrs or sharp edges.

• Do not make any adjustments outside of the specified range.

Applying Isopropyl Alcohol

Care should be exercised when using isopropyl alcohol, due to its flammability. When using alcohol to clean parts, observe the following precautions:

• Remove power from the equipment.

• Use alcohol in small quantities to avoid spillage

or puddling. Any spillage should be cleaned up with rags and disposed of properly.

• Be sure that there is adequate ventilation.

• Allow a surface which has been in contact with

alcohol to dry for a few minutes to ensure that the alcohol has evaporated completely before applying power or installing covers.

Summary

It is the responsibility of every technician to use professional skills when servicing Konica products. There are no short cuts to high-quality service. Each copier must be thoroughly inspected with respect to safety considerations as part of every routine service call. The operability of the copier, and more importantly, the safety of those who operate or service the copier, are directly dependent upon the conscientious effort of each and every technician.

Remember...when performing service calls, use good judgement (have a watchful eye) to identify safety hazards or potential safety hazards that may be present, and correct these problem areas as they are identified -- the safety of those who operate the copier as well as those who service the copier depend on it!

GENERAL,

MECHANICAL/

ELECTRICAL

SPECIFICATIONS

Type : Sheet turnover device for making automatic

2-sided copies Installation : Mounted to the copier Modes : Exit mode

Duplex mode

Max. Storage Capacity Exit Tray Capacity : 250 sheets of 90-g/m2 or 24-lb. paper Registration : Center

Power Source : DC24V (supplied from copier) Power Consumption : 30W or less

Dimensions : Width ..... 121 mm or 4-3/4"

Weight : 8.9 kg or 19-1/2 lbs. (including the mount) Environmental Requirements

Paper Requirements

- Exit mode Type of Paper : Recommended paper weighing 60 to 90 g/m2 or

Paper Size : A5 lengthwise to A3 lengthwise and A3 Wide or

- Duplex mode Type of Paper : Recommended paper weighing 60 to 90 g/m2 or

Paper Size : A5 lengthwise to A3 lengthwise or 5-1/2" × 8-1/2"

: 2 (A4 crosswise or smaller, two-sheet paper

attraction mode)

Depth ..... 536 mm or 21"

Height ....345 mm or 13-1/2"

: Same as copier

16 to 24 lbs., OHP transparencies, thick paper

weighing 157 g/m2 or 42 lbs. max.

5-1/2" × 8-1/2" lengthwise to 11" × 17" lengthwise

and Full Bleed

16 to 24 lbs.

lengthwise to 11" × 17" lengthwise

M-1

PARTS IDENTIFICATION

4458M001AA

4458M002AA

No. Name No. Name

1 Exit Tray 6 Exit Section Lower Cover 2 Exit Section Cover 7 Turnover Tray 3 Rear Cover 8 Exit/Turnover Switching Finger 4 Top Cover 9 Vertical Transport Guide 5 Front Cover 10 Hookup Cord

M-2

CROSS-SECTIONAL VIEW

No. Name Function

1 Exit Rollers Feed the copy out onto the Exit Tray.

Exit/Turnover

Switching Finger Vertical Transport

Guide Vertical Transport

Rollers Vertical Transport

Sensor PC3 Duplex Paper

Take-Up Port

7 Turnover Tray

8 Turnover Rollers

Switchback

Sensor PC1

Directs a copy for exit or turnover depending on the operating mode.

Serves as a guide for the copy for turnover. Used also for clearing a misfeed.

Transports the copy for turnover. Also removes the fuser oil from the copy.

Detects a copy to be later turned over. Serves also as a misfeed sensor.

The port through which the copy which has been turned over is taken up and fed into the copier for the second copy cycle.

Prevents the portion of the copy out of the Duplex Unit for turnover from drooping down.

Reverse the copy fed from the vertical transport section (switchback motion) so that it can be taken up and fed again into the copier.

Detects the reference timing for the switchback motion of the copy fed from the vertical transport section.

2 3

4458M003AA

M-3

DRIVE SYSTEM

Turnover Roller

PG2

Exit Roller

Drive from

Copier

Vertical Transport Roller

PG1

CL1

4458M004AA

Gear

Symbol

G1 30 G2 24 G3 24 G4 19 G5 33

No. of

Teeth

Pulley

Symbol

PG1 31 28 PG2 15 64

No. of

Teeth, Gear

Teeth, Pulley

Pulley

Symbol No. of Teeth

P1 16

M-4

No. of

Belt

Symbol

B1 288 B2 191.01

Length

(mm)

ELECTRICAL COMPONENTS LAYOUT

CL1

PC2

PC3

PC1

◆ Function of Each Component

Symbol Name Input Signals (∗) Function

PWB-A Drive Board

SL1

CL1

PC1 (PJ2A-8)

PC2 (PJ3A-2)

PC3 (PJ2A-9)

S1 (PJ2A-6)

Turnover Motor

Exit/Turnover Switching Solenoid

Vertical Transport Clutch

Switchback Sensor

Motor Pulse Sensor

Vertical Transport Sensor

Duplex Unit Set Switch

Paper present: Paper not present: Unblocked: Blocked: Paper present:

Paper not present: Unit in position:

Unit out of position:

Performs communication with the copier and controls the electrical components of the Duplex Unit.

Drives the Turnover Rollers to effect a switchback motion.

Moves the Exit/Turnover Switching Finger to change the paper path.

Controls the start and stop of the Vertical Transport Rollers to keep the copy in the standby state.

Detects the reference timing for a switchback motion.

H H

Detects the speed of M1.

L L

Detects the copy present at the vertical transport section.

Detects whether or not the Duplex Unit is installed in position.

SL1

PWB-A

4458M005AA

∗ Signals at the print jack on PWB-A.

M-5

DESCRIPTION OF EACH MECHANISM AND CONTROL

6-1. Exit/Turnover Switching Mechanism

• The exit/turnover switching mechanism uses the Exit/Turnover Switching

Finger that is moved to change the paper path either for exit or turnover.

• When in the Exit mode or when the copy is to be fed out in the Duplex

mode, Exit/Turnover Switching Solenoid SL1 remains deenergized and the copy moves above the Exit/Turnover Switching Finger and is fed out of the copier by the Exit Rollers.

• When the copy is to be turned over in the Duplex mode, SL1 is energized

and the copy moves beneath and along the Exit/Turnover Switching Finger and is fed by the Vertical Transport Rollers of the Duplex Unit down towards the turnover section.

• As noted above, SL1 moves the Exit/Turnover Switching Finger to change

the paper path. It is energized when a LOW signal from the copier is input to PJ2A-1 on PWB-A.

SL1: Deenergized

Exit

Paper Exit Roller of Copier

Exit Roller

SL1: Energized

Exit/Turnover Switching Finger

To Turnover Section

4458M006AA

M-6

6-2. Fuser Oil Cleaning Mechanism

• Since fuser oil is on the front side of the paper after the fusing process, it is

transferred onto the surface of the PC Drum via the Transfer Film during the second copy process of 2-sided copying, which results in image problems. Silicone rubber rollers are used as the Vertical Transport Rollers of the Duplex Unit. They function to recover fuser oil from the surface of the paper.

6-3. Paper Standby Control

• In a Duplex mode making two or more copy sets of an original set (which

involves two-sheet paper attraction), two sheets of paper are present in the Duplex Unit, one waiting for take-up from the Duplex Unit following the turnover cycle and the other remaining stationary at the vertical transport section. (See "7. OPERATION AND CONTROL" that follows.)

• There is no problem with the paper waiting for take-up from the Duplex Unit

as it is driven independently of the copier drive. The paper at the vertical transport section is, however, being transported and the drive from the copier must be cut off. To accomplish this, Vertical Transport Clutch CL1 is mounted on the shaft of the Vertical Transport Roller and it couples or cuts off the copier drive to the roller.

• CL1 is energized to stop the Vertical Transport Roller rotation when a LOW

signal from the copier is input to PJ2A-4 on PWB-A.

M-7

6-4. Switchback Operation (Turnover)

• The Turnover Roller turns forward to transport the copy to the turnover

section and, as soon as the trailing edge of the copy moves past Switchback Sensor PC1, it stops turning. The Turnover Roller then turns backward to turn over the copy and feed it back into the copier.

• The drive for the Turnover Roller comes from Turnover Motor M1 which is

turned forward, backward, or stopped by the signals fed from the copier as follows.

PJ2A-2 PJ2A-3 Copy Motion

Turning forward Transported towards Turnover Tray

Turning backward

Stopped Stationary

L H H

Transported towards Duplex paper

take-up side

Copy Transported Towards Turnover Tray

Copy

Turnover Tray

Standby Position

Horizontal Transport Sensor of Copier

Turnover Position (Copy is temporarily stationary)

Switchback Sensor PC1

4458M007AB

M-8

+ 40 hidden pages

Konica Minolta AD-723 User Manual

CONTENTS

SAFETY PRECAUTIONS

SPECIFICATIONS

PARTS IDENTIFICATION

DRIVE SYSTEM

ELECTRICAL COMPONENTS LAYOUT

DESCRIPTION OF EACH MECHANISM AND CONTROL