Konica Minolta bizhub 750 User manual

SERVICE MANUAL
2005.08
Ver. 1.0
750/600
Theory of Operation
Main body

SAFETY AND IMPORTANT WARNING ITEMS
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, Konica Minolta Business Technologies, INC. (hereafter
called the KMBT) strongly recommends that all servicing be performed only by KMBT-
trained service technicians.
Changes may have been made to this product to improve its performance after this Service
Manual was printed. Accordingly, KMBT 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 using the
copier. General
precaution
Electric hazard High
temperature
:Prohibition when using the
copier. General
prohibition
Do not touch
with wet hand
Do not
disassemble
:Direction when using the
copier. General
instruction
Unplug Ground/Earth

SAFETY AND IMPORTANT WARNING ITEMS
S-2
[1] MODIFICATIONS NOT AUTHORIZED BY KONICA MINOLTA
BUSINESS TECHNOLOGIES, INC.
Konica Minolta 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
Prohibited Actions
DANGER
• Using any cables or power cord not specified by KMBT.
• Using any fuse or thermostat not specified by KMBT.
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 KMBT
• Using parts not specified by KMBT

SAFETY AND IMPORTANT WARNING ITEMS
S-3
[2] POWER PLUG SELECTION
In some countries or areas, the power plug provided with the product may not fit wall outlet
used in the area. In that case, it is obligation of customer engineer (hereafter called the CE)
to attach appropriate power plug or power cord set in order to connect the product to the
supply.
Power Cord Set or Power Plug
WARNING
• Use power supply cord set which meets the following
criteria:
- provided with a plug having configuration intended for
the connection to wall outlet appropriate for the prod-
uct's rated voltage and current, and
- the plug has pin/terminal(s) for grounding, and
- provided with three-conductor cable having enough cur-
rent capacity, and
- the cord set meets regulatory requirements for the area.
Use of inadequate cord set leads to fire or electric shock.
• Attach power plug which meets the following criteria:
- having configuration intended for the connection to wall
outlet appropriate for the product's rated voltage and
current, and
- the plug has pin/terminal(s) for grounding, and
- meets regulatory requirements for the area.
Use of inadequate cord set leads to the product connect-
ing to inadequate power supply (voltage, current capacity,
grounding), and may result in fire or electric shock.
• Conductors in the power cable must be connected to ter-
minals of the plug according to the following order:
• Black or Brown: L (line)
• White or Light Blue: N (neutral)
• Green/Yellow: PE (earth)
Wrong connection may cancel safeguards within the
product, and results in fire or electric shock.
AC230V
AC208V 240V

SAFETY AND IMPORTANT WARNING ITEMS
S-4
[3] CHECKPOINTS WHEN PERFORMING ON-SITE SERVICE
Konica Minolta brand products are extensively tested before shipping, to ensure that all
applicable safety standards are met, in order to protect the customer and 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
Connection to Power Supply
WARNING
• Check that mains voltage is as specified.
Connection to wrong voltage supply may result in fire or
electric shock.
• Connect power plug directly into wall outlet having same
configuration as the plug.
Use of an adapter leads to the product connecting to
inadequate power supply (voltage, current capacity,
grounding), and may result in fire or electric shock.
If proper wall outlet is not available, advice the customer
to contact qualified electrician for the installation.
• 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.
• 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.
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SAFETY AND IMPORTANT WARNING ITEMS
S-5
• 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.
Connection to Power Supply
WARNING
Power Plug and Cord
WARNING
• When using the power cord set (inlet type) that came with
this product, make sure the connector is securely inserted
in the inlet of the product.
When securing measure is provided, secure the cord with
the fixture properly.
If the power cord (inlet type) is not connected to the prod-
uct 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.
• 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 or cord set (with plug and connec-
tor on each end) specified by KMBT.
Using the damaged power cord may result in fire or elec-
tric shock.
• Do not bundle or tie the power cord.
Overheating may occur there, leading to a risk of fire.

SAFETY AND IMPORTANT WARNING ITEMS
S-6
• 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.
Power Plug and Cord
WARNING
Wiring
WARNING
• Never use multi-plug adapters to plug multiple power cords
in the same outlet.
If used, the risk of fire exists.
• 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.

SAFETY AND IMPORTANT WARNING ITEMS
S-7
2. Installation Requirements
Prohibited Installation Places
WARNING
• 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.
When not Using the Product for a long time
WARNING
• 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.
Ventilation
CAUTION
• 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
Fixing
CAUTION
• Be sure to lock the caster stoppers.
In the case of an earthquake and so on, the product may
slide, leading to a injury.

SAFETY AND IMPORTANT WARNING ITEMS
S-8
Inspection before Servicing
CAUTION
• Before conducting an inspection, read all relevant docu-
mentation (service manual, technical notices, etc.) and
proceed with the inspection following the prescribed pro-
cedure in safety clothes, using only the prescribed tools.
Do not make any adjustment not described in the docu-
mentation.
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.
Work Performed with the Product Powered On
WARNING
• 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.

SAFETY AND IMPORTANT WARNING ITEMS
S-9
Safety Checkpoints
WARNING
• 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.
• 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.