Develop QC 2235 Plus User manual

DEVELOP
SERVICE MANUAL
THEORY OF OPERATION
QC 2235plus

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
S-1
Read carefully the Safety and Important Warning Items described below to understand
them before doing service work.
Because of possible hazards to an inexperienced person servicing this product as well as
the risk of damage to the product, Develop GmbH. (hereafter called the Develop) strongly
recommends that all servicing be performed only by Develop-trained service technicians.
Changes may have been made to this product to improve its performance after this Service
Manual was printed. Accordingly, Develop does not warrant, either explicitly or implicitly,
that the information contained in this Service Manual is complete and accurate.
The user of this Service Manual must assume all risks of personal injury and/or damage to
the product while servicing the product for which this Service Manual is intended.
Therefore, this Service Manual must be carefully read before doing service work both in the
course of technical training and even after that, for performing maintenance and control of
the product properly.
Keep this Service Manual also for future service.
In this Service Manual, each of three expressions " DANGER", " WARNING", and
" CAUTION" is defined as follows together with a symbol mark to be used in a limited
meaning.
When servicing the product, the relevant works (disassembling, reassembling, adjustment,
repair, maintenance, etc.) need to be conducted with utmost care.
Symbols used for safety and important warning items are defined as follows:
SAFETY AND IMPORTANT WARNING ITEMS
IMPORTANT NOTICE
DESCRIPTION ITEMS FOR DANGER,
WARNING AND CAUTION
DANGER: Action having a high possibility of suffering death or serious injury
WARNING: Action having a possibility of suffering death or serious injury
CAUTION: Action having a possibility of suffering a slight wound, medium
trouble, and property damage
:Precaution when servicing the
product. General
precaution
Electric hazard High temperature
:Prohibition when servicing the
product. General
prohibition
Do not touch
with wet hand
Do not
disassemble
:Direction when servicing the
product. General
instruction
Unplug Ground/Earth

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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[1] MODIFICATIONS NOT AUTHORIZED BY DEVELOP GMBH
Develop brand products are renowned for their high reliability. This reliability is achieved
through high-quality design and a solid service network.
Product design is a highly complicated and delicate process where numerous mechanical,
physical, and electrical aspects have to be taken into consideration, with the aim of arriving
at proper tolerances and safety factors. For this reason, unauthorized modifications involve
a high risk of degradation in performance and safety. Such modifications are therefore
strictly prohibited. the points listed below are not exhaustive, but they illustrate the reason-
ing behind this policy.
SAFETY WARNINGS
DANGER : PROHIBITED ACTIONS
• Using any cables or power cord not specified by Develop.
• Using any fuse or thermostat not specified by Develop.
Safety will not be assured, leading to a risk of fire and
injury.
• Disabling fuse functions or bridging fuse terminals with
wire, metal clips, solder or similar object.
• Disabling relay functions (such as wedging paper between
relay contacts)
• Disabling safety functions (interlocks, safety circuits, etc.)
Safety will not be assured, leading to a risk of fire and
injury.
• Making any modification to the product unless instructed
by Develop
• Using parts not specified by Develop

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
S-3
[2] CHECKPOINTS WHEN PERFORMING ON-SITE SERVICE
Develop brand products are extensively tested before shipping, to ensure that all applicable
safety standards are met, in order to protect the customer and customer engineer (hereaf-
ter called the CE) from the risk of injury. However, in daily use, any electrical equipment
may be subject to parts wear and eventual failure. In order to maintain safety and reliability,
the CE must perform regular safety checks.
1. Power Supply
WARNING: Wall Outlet
• Check that mains voltage is as specified. Plug the power
cord into the dedicated wall outlet with a capacity greater
than the maximum power consumption.
If excessive current flows in the wall outlet, fire may
result.
• If two or more power cords can be plugged into the wall
outlet, the total load must not exceed the rating of the wall
outlet.
If excessive current flows in the wall outlet, fire may
result.
WARNING: Power Plug and Cord
• Make sure the power cord is plugged in the wall outlet
securely.
Contact problems may lead to increased resistance,
overheating, and the risk of fire.
• Check whether the power cord is damaged. Check
whether the sheath is damaged.
If the power plug, cord, or sheath is damaged, replace
with a new power cord (with plug and connector on each
end) specified by Develop. Using the damaged power
cord may result in fire or electric shock.

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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• When using the power cord (inlet type) that came with this
product, be sure to observe the following precautions:
a. Make sure the connector is securely inserted in the inlet
on the rear panel of the product.
Secure the cord with a fixture properly.
b. If the power cord or sheath is damaged, replace with a
new power cord (with plugs on both ends) specified by
Develop.
If the power cord (inlet type) is not connected to the
product securely, a contact problem may lead to
increased resistance, overheating, and risk of fire.
• Check whether the power cord is not stepped on or
pinched by a table and so on.
Overheating may occur there, leading to a risk of fire.
• Do not bundle or tie the power cord.
Overheating may occur there, leading to a risk of fire.
• Check whether dust is collected around the power plug
and wall outlet.
Using the power plug and wall outlet without removing
dust may result in fire.
• Do not insert the power plug into the wall outlet with a wet
hand.
The risk of electric shock exists.
• When unplugging the power cord, grasp the plug, not the
cable.
The cable may be broken, leading to a risk of fire and
electric shock.
WARNING: Power Plug and Cord
WARNING: Wiring
• Never use multi-plug adapters to plug multiple power cords
in the same outlet.
If used, the risk of fire exists.

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
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2. Installation Requirements
• When an extension cord is required, use a specified one.
Current that can flow in the extension cord is limited, so
using a too long extension cord may result in fire.
Do not use an extension cable reel with the cable taken
up. Fire may result.
WARNING: Wiring
WARNING: Ground connection
• Check whether the product is grounded properly.
If current leakage occurs in an ungrounded product, you
may suffer electric shock while operating the product.
Connect power plug to grounded wall outlet.
WARNING: Prohibited Installation Place
• Do not place the product near flammable materials or vola-
tile materials that may catch fire.
A risk of fire exists.
• Do not place the product in a place exposed to water such
as rain.
A risk of fire and electric shock exists.
WARNING: When not using product for a long time
• When the product is not used over an extended period of
time (holidays, etc.), switch it off and unplug the power
cord.
Dust collected around the power plug and outlet may
cause fire.

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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CAUTION: Ventilation
• The product generates ozone gas during operation, but it
will not be harmful to the human body.
If a bad smell of ozone is present in the following cases,
ventilate the room.
a. When the product is used in a poorly ventilated room
b. When taking a lot of copies
c. When using multiple products at the same time
CAUTION: Fixing
• Be sure to lock the caster stoppers.
In the case of an earthquake and so on, the product may
slide, leading to a injury.
CAUTION: Inspection before Servicing
• Before conducting an inspection, read all relevant docu-
mentation (service manual, technical notices, etc.) and
proceed with the inspection following the prescribed pro-
cedure, using only the prescribed tools. Do not make any
adjustment not described in the documentation.
If the prescribed procedure or tool is not used, the prod-
uct may break and a risk of injury or fire exists.
• Before conducting an inspection, be sure to disconnect
the power plugs from the product and options.
When the power plug is inserted in the wall outlet, some
units are still powered even if the POWER switch is
turned OFF. A risk of electric shock exists.
• The area around the fixing unit is hot.
You may get burnt.

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
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WARNING: Work Performed with the product Powered
• Take every care when making adjustments or performing
an operation check with the product powered.
If you make adjustments or perform an operation check
with the external cover detached, you may touch live or
high-voltage parts or you may be caught in moving gears
or the timing belt, leading to a risk of injury.
• Take every care when servicing with the external cover
detached.
High-voltage exists around the drum unit. A risk of elec-
tric shock exists.
WARNING: Safety Checkpoints
• Check the exterior and frame for edges, burrs, and other
damages.
The user or CE may be injured.
• Do not allow any metal parts such as clips, staples, and
screws to fall into the product.
They can short internal circuits and cause electric shock
or fire.
• Check wiring for squeezing and any other damage.
Current can leak, leading to a risk of electric shock or
fire.
• Carefully remove all toner remnants and dust from electri-
cal parts and electrode units such as a charging corona
unit.
Current can leak, leading to a risk of product trouble or
fire.
• Check high-voltage cables and sheaths for any damage.
Current can leak, leading to a risk of electric shock or
fire.
• Check electrode units such as a charging corona unit for
deterioration and sign of leakage.
Current can leak, leading to a risk of trouble or fire.

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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• Before disassembling or adjusting the write unit (P/H unit)
incorporating a laser, make sure that the power cord has
been disconnected.
The laser light can enter your eye, leading to a risk of
loss of eyesight.
• Do not remove the cover of the write unit. Do not supply
power with the write unit shifted from the specified mount-
ing position.
The laser light can enter your eye, leading to a risk of
loss of eyesight.
• When replacing a lithium battery, replace it with a new lith-
ium battery specified in the Parts Guide Manual. Dispose
of the used lithium battery using the method specified by
local authority.
Improper replacement can cause explosion.
• After replacing a part to which AC voltage is applied (e.g.,
optical lamp and fixing lamp), be sure to check the installa-
tion state.
A risk of fire exists.
• Check the interlock switch and actuator for loosening and
check whether the interlock functions properly.
If the interlock does not function, you may receive an
electric shock or be injured when you insert your hand in
the product (e.g., for clearing paper jam).
• Make sure the wiring cannot come into contact with sharp
edges, burrs, or other pointed parts.
Current can leak, leading to a risk of electric shock or
fire.
• Make sure that all screws, components, wiring, connec-
tors, etc. that were removed for safety check and mainte-
nance have been reinstalled in the original location. (Pay
special attention to forgotten connectors, pinched cables,
forgotten screws, etc.)
A risk of product trouble, electric shock, and fire exists.
WARNING: Safety Checkpoints

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
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WARNING: HANDLING OF CONSUMABLE
• Toner and developer are not harmful substances, but care
must be taken not to breathe excessive amounts or let the
substances come into contact with eyes, etc. It may be
stimulative.
If the substances get in the eye, rinse with plenty of water
immediately. When symptoms are noticeable, consult a
physician.
• Never throw the used cartridge and toner into fire.
You may be burned due to dust explosion.
CAUTION: HANDLING OF SERVICE MATERIALS
• Unplug the power cord from the wall outlet.
Drum cleaner (isopropyl alcohol) and roller cleaner (ace-
tone-based) are highly flammable and must be handled
with care. A risk of fire exists.
• Do not replace the cover or turn the product ON before
any solvent remnants on the cleaned parts have fully
evaporated.
A risk of fire exists.
• Use only a small amount of cleaner at a time and take
care not to spill any liquid. If this happens, immediately
wipe it off.
A risk of fire exists.
• When using any solvent, ventilate the room well.
Breathing large quantities of organic solvents can lead to
discomfort.

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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[3] MEASURES TO TAKE IN CASE OF AN ACCIDENT
1. If an accident has occurred, the distributor who has been notified first must immedi-
ately take emergency measures to provide relief to affected persons and to prevent
further damage.
2. If a report of a serious accident has been received from a customer, an on-site evalua-
tion must be carried out quickly and Develop must be notified.
3. To determine the cause of the accident, conditions and materials must be recorded
through direct on-site checks, in accordance with instructions issued by Develop.
[4] CONCLUSION
1. Safety of users and customer engineers depends highly on accurate maintenance and
administration. Therefore, safety can be maintained by the appropriate daily service
work conducted by the customer engineer.
2. When performing service, each product on the site must be tested for safety. The cus-
tomer engineer must verify the safety of parts and ensure appropriate management of
the equipment.
[5] FUSE
[6] LED Radiation Safety
• This product is a copier which operates by means of a LED (light emitting diodes) expo-
sure system. There is no possibility of danger from the LED optical radiation, because
the LED optical radiation level dose not exceed the accessible radiation limit of class 1
under all conditions of operation, maintenance, service and failure.
CAUTION
Double pole / neutral fusing
ATTENTION
Double pôle / fusible sur le neutre.

QC 2235plus Field Service Ver1.0 Mar. 2004 SAFETY AND IMPORTANT WARNING
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Caution labels shown are attached in some areas on/in the machine.
When accessing these areas for maintenance, repair, or adjustment, special care should
be taken to avoid burns and electric shock.
INDICATION OF WARNING ON THE MACHINE
4036fsS001c0
High voltage
High voltage
High temperature
High temperature

SAFETY AND IMPORTANT WARNING ITEMS QC 2235plus Field Service Ver1.0 Mar.
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4036fsS002c0
4036fsS003c0
Do not throw into a fire
High voltage
High voltage

DEVELOP
SERVICE MANUAL
THEORY OF OPERATION
QC 2235plus
Main Unit

QC 2235plus Theory of Operation Ver1.0 Mar. 2004
i
I Outline
II Composition/Operation
CONTENTS
IOutline
1. System configuration............................................................................................1-1
2. Product specifications ..........................................................................................1-3
2.1 Type ...................................................................................................................1-3
2.2 Functions ...........................................................................................................1-3
2.3 Types of paper ...................................................................................................1-4
2.4 Maintenance ......................................................................................................1-4
2.5 Machine specifications.......................................................................................1-4
2.6 Operating environment ......................................................................................1-4
2.7 Built-in controllers ..............................................................................................1-5
3. Center cross section ............................................................................................1-6
4. Paper path............................................................................................................1-7
5. Image creation process........................................................................................1-8
II Composition/Operation
1. Overall composition..............................................................................................2-1
1.1 Timing chart at machine power up ....................................................................2-1
1.2 Control block diagram........................................................................................2-2
2. Scanner section (IR section) ................................................................................2-3
2.1 Composition.......................................................................................................2-3
2.2 Drive ..................................................................................................................2-5
2.3 Operation........................................................................................................... 2-5
2.3.1 Scan and Exposure Lamp control ................................................................2-5
2.3.2 Original Size Detection control .....................................................................2-6
3. Write section (PH section)....................................................................................2-9
3.1 Composition.......................................................................................................2-9
3.2 Operation.........................................................................................................2-10
3.2.1 Outline ........................................................................................................2-10
3.2.2 Color Shift Correction System ....................................................................2-11
4. Imaging Unit section (IU section) .......................................................................2-12
4.1 Composition.....................................................................................................2-12
4.2 Drive ................................................................................................................2-13
4.3 Operation.........................................................................................................2-14
4.3.1 IU Life control..............................................................................................2-14
5. Photo Conductor section....................................................................................2-15
5.1 Composition.....................................................................................................2-15
5.2 Drive ................................................................................................................2-15

QC 2235plus Theory of Operation Ver1.0 Mar. 2004
ii
I Outline
II Composition/Operation
5.3 Operation......................................................................................................... 2-16
5.3.1 PC Drum Drive mechanism........................................................................ 2-16
5.3.2 PC Drum Phase control ............................................................................. 2-16
5.3.3 PC Drum small amount rotation control ..................................................... 2-17
6. Charge Corona section ...................................................................................... 2-18
6.1 Operation......................................................................................................... 2-19
6.1.1 PC Drum Charge Corona ON/OFF control................................................. 2-19
6.1.2 Cleaning/Main Erase mechanism............................................................... 2-19
7. Developing section............................................................................................. 2-20
7.1 Composition .................................................................................................... 2-20
7.2 Drive ................................................................................................................ 2-21
7.3 Operation......................................................................................................... 2-22
7.3.1 Developing Drive control ............................................................................ 2-22
7.3.2 Developer flow............................................................................................ 2-22
7.3.3 Developing bias.......................................................................................... 2-23
7.3.4 HMT (High grade Micro Toning) development............................................ 2-23
7.3.5 Developer scattering prevention mechanism.............................................. 2-23
7.3.6 ATDC Sensor control.................................................................................. 2-24
8. Toner Supply section.......................................................................................... 2-26
8.1 Composition .................................................................................................... 2-26
8.2 Drive ................................................................................................................ 2-27
8.3 Operation......................................................................................................... 2-28
8.3.1 Toner Replenishing mechanism/control ..................................................... 2-28
8.3.2 Toner Near-Empty and Toner Empty detection control............................... 2-29
8.3.3 Shutter mechanism .................................................................................... 2-30
9. Transfer Corona section..................................................................................... 2-31
9.1 Composition .................................................................................................... 2-31
9.1.1 1st Image Transfer section ......................................................................... 2-31
9.1.2 2nd Image Transfer section ........................................................................ 2-33
9.2 Drive ................................................................................................................ 2-34
9.2.1 1st Image Transfer section ......................................................................... 2-34
9.2.2 2nd Image Transfer section ........................................................................ 2-35
9.3 Operation......................................................................................................... 2-35
9.3.1 Transfer Belt speed control......................................................................... 2-35
9.3.2 1st Image Transfer Roller mechanism........................................................ 2-36
9.3.3 2nd Image Transfer Roller pressure mechanism........................................ 2-39
9.3.4 AIDC Sensor Shutter mechanism .............................................................. 2-40
9.3.5 ATVC (Auto Transfer Voltage Control) ........................................................ 2-41

QC 2235plus Theory of Operation Ver1.0 Mar. 2004
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I Outline
II Composition/Operation
9.3.6 Transfer Belt cleaning .................................................................................2-42
9.3.7 2nd Image Transfer Roller cleaning............................................................2-43
9.3.8 Charge neutralization and separation of paper ..........................................2-44
9.3.9 Detection of New Transfer Belt Unit............................................................2-45
9.3.10 ACS control.................................................................................................2-46
10. Toner Collecting section ..................................................................................... 2-47
10.1 Composition.....................................................................................................2-47
10.2 Drive ................................................................................................................2-48
10.3 Operation.........................................................................................................2-49
10.3.1 Toner collecting mechanism .......................................................................2-49
10.3.2 Waste Toner Bottle-in-position detection ....................................................2-49
10.3.3 Waste Toner Near-Full/Full detection control..............................................2-50
11. Paper feed section..............................................................................................2-51
11.1 Composition.....................................................................................................2-51
11.1.1 Tray1...........................................................................................................2-51
11.1.2 Tray2...........................................................................................................2-52
11.2 Drive ................................................................................................................2-54
11.2.1 Tray1...........................................................................................................2-54
11.2.2 Tray2...........................................................................................................2-54
11.3 Operation.........................................................................................................2-55
11.3.1 Paper Take-up control (Tray1).....................................................................2-55
11.3.2 Tray1 double feed control............................................................................2-55
11.3.3 Deceleration control....................................................................................2-55
11.3.4 Paper supply level detection control ...........................................................2-56
11.3.5 Paper Near-Empty/Paper Empty detection.................................................2-56
11.3.6 Tray1 paper type detting .............................................................................2-57
11.3.7 Paper size detection control .......................................................................2-58
11.3.8 Tray2 paper lifting motion control................................................................2-61
12. Bypass section ...................................................................................................2-62
12.1 Composition.....................................................................................................2-62
12.2 Drive ................................................................................................................2-63
12.3 Operation.........................................................................................................2-64
12.3.1 Bypass Paper Take-up control....................................................................2-64
12.3.2 Paper Empty detection ...............................................................................2-64
12.3.3 Bypass Paper Lifting Motion Control ..........................................................2-64
12.3.4 Paper size detection ...................................................................................2-66
13. Conveyance section ...........................................................................................2-68
13.1 Composition.....................................................................................................2-68

QC 2235plus Theory of Operation Ver1.0 Mar. 2004
iv
I Outline
II Composition/Operation
14. Synchronizing Roller section.............................................................................. 2-69
14.1 Composition .................................................................................................... 2-69
14.2 Drive ................................................................................................................ 2-69
14.3 Operation......................................................................................................... 2-70
14.3.1 Synchronizing Roller control....................................................................... 2-70
14.3.2 OHP detection............................................................................................ 2-71
15. Fusing section.................................................................................................... 2-72
15.1 Composition .................................................................................................... 2-72
15.2 Drive ................................................................................................................ 2-73
15.3 Operation......................................................................................................... 2-74
15.3.1 Fusing Roller drive control.......................................................................... 2-74
15.3.2 Fusing Roller pressure/retraction mechanism............................................ 2-76
15.3.3 Fusing temperature control ........................................................................ 2-77
15.3.4 Protection against abnormal conditions ..................................................... 2-79
15.3.5 Detection of a New Fusing Unit.................................................................. 2-81
15.3.6 PPM control................................................................................................ 2-81
16. Paper exit section............................................................................................... 2-82
16.1 Composition .................................................................................................... 2-82
16.2 Drive ................................................................................................................ 2-83
17. Image stabilization control ................................................................................. 2-84
17.1 Overview ......................................................................................................... 2-84
17.2 Operation......................................................................................................... 2-85
17.2.1 Background margin control ........................................................................ 2-85
17.2.2 AIDC Sensor LED intensity control ............................................................ 2-85
17.2.3 Max. density control ................................................................................... 2-85
17.2.4 g correction control..................................................................................... 2-85
17.3 Operation timing .............................................................................................. 2-85
17.4 Operation flow ................................................................................................. 2-86
18. Image processing............................................................................................... 2-87
18.1 Scanner section image processing block diagram .......................................... 2-87
18.2 Write section image processing block diagram ............................................... 2-89
19. Other control ...................................................................................................... 2-91
19.1 Fan control....................................................................................................... 2-91
19.1.1 Construction ............................................................................................... 2-91
19.1.2 Operation.................................................................................................... 2-92
19.2 Power distribution control at machine power up .............................................. 2-93
19.2.1 Parts operated when the Power Switch is turned ON ................................ 2-93
19.3 Counter control................................................................................................ 2-94
19.3.1 Construction ............................................................................................... 2-94