Service Manuals, User Guides, Schematic Diagrams or docs for : LG Audio CM8450 LG+CM8450
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Internal Use Only
Website http://biz.lgservice.com
SERVICE MANUAL
MINI HI-FI SYSTEM
SERVICE MANUAL
MODEL: CM8450 (CM8450, CMS8450F/W)
MODEL: CM8450
(CM8450, CMS8450F/W)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P/NO : AFN77255256 MAY, 2015
CONTENTS
SECTION 1 ........ GENERAL
SECTION 2 ........ CABINET & MAIN CHASSIS
SECTION 3 ........ ELECTRICAL
SECTION 4 ........ REPLACEMENT PARTS LIST
1-1
SECTION 1
SUMMARY
CONTENTS
SERVICING PRECAUTIONS ............................................................................................................................ 1-3
ESD PRECAUTIONS ......................................................................................................................................... 1-5
HIDDEN KEY MODE ......................................................................................................................................... 1-6
SERVICE INFORMATION FOR EEPROM ........................................................................................................ 1-7
PROGRAM DOWNLOAD GUIDE...................................................................................................................... 1-8
FOTA UPDATE ................................................................................................................................................ 1-11
SPECIFICATIONS ........................................................................................................................................... 1-12
1-2
SERVICING PRECAUTIONS
NOTES REGARDING HANDLING OF THE PICK-UP
1. Notes for transport and storage
1) The pick-up should always be left in its conductive bag until immediately prior to use.
2) The pick-up should never be subjected to external pressure or impact.
Storage in conductive bag Drop impact
2. Repair notes
1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.
2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and
impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or
damage to the printed-circuit board.
3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason
the adjustment point and installation screws should absolutely never be touched.
4) Laser beams may damage the eyes!
Absolutely never permit laser beams to enter the eyes!
Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.
NEVER look directly at the laser beam, and don't allow
contact with fingers or other exposed skin.
5) Cleaning the lens surface
If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used
for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cot-
ton swab should be used, taking care not to distort lens.
Pressure
Magnet
Pressure
How to hold the pick-up
Cotton swab
Conductive Sheet
6) Never attempt to disassemble the pick-up.
Spring has excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab.
(Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much
of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.
1-3
NOTES REGARDING COMPACT DISC PLAYER REPAIRS
1. Preparations
1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components
are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components
can be damaged, and for that reason components should be handled with care.
2) The pick-up is composed of many optical components and other high-precision components. Care must be
taken, therefore, to avoid repair or storage where the temperature or humidity is high, where strong magne-
tism is present, or where there is excessive dust.
2. Notes for repair
1) Before replacing a component part, first disconnect the power supply lead wire from the unit
2) All equipment, measuring instruments and tools must be grounded.
3) The workbench should be covered with a conductive sheet and grounded.
When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is
because there is the possibility of damage by static electricity.)
4) To prevent AC leakage, the metal part of the soldering iron should be grounded.
5) Workers should be grounded by an armband (1 M)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent
static electricity changes in the clothing to escape from the armband.
7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.
Armband
Resistor
(1 M)
Resistor
Conductive
(1 M)
Sheet
1-4
ESD PRECAUTIONS
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated
circuits and some field-effect transistors and semiconductor chip components. The following techniques should
be used to help reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device, which should be removed for potential shock reasons
prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surface
such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can
generate electrical charges sufficient to damage ESD devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD
devices.
6. Do not remove a replacement ESD device from its protective package until immediately before you are
ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable conductive materials).
7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the
protective material to the chassis or circuit assembly into which the device will by installed.
CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER
SAFETY PRECAUTIONS.
8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate
static electricity sufficient to damage an ESD device).
CAUTION. GRAPHIC SYMBOLS
THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS
INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED
"DANGEROUS VOLTAGE" THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF
ELECTRIC SHOCK.
THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE
SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE
LITERATURE.
1-5
HIDDEN KEY MODE
HIDDEN MODE KEYS
Version Check Front Stop + RMC ` ' for 5s
EEPROM Initial Front Stop + RMC ` ' for 5s
EEPROM Edit Front Stop + RMC ` ' for 5s
APD Test Display Front Stop + RMC `3' for 5s
Clip Front Stop + RMC `Mute' for 5s
Disc Lock On/Off Front Stop + RMC `Stop' for 5s
Front Stop + RMC `EQ' for 5s
Power Disc Lock On/Off or
Front Stop + Front Open for 5s
Demo All Key Lock On/Off Front Stop + RMC `9' for 5s
BT Auto Power On/Off Front/RMC Power Key for 5s
Child Safe On/Off Volume 0(Min) + Front ENTER Key for 3s
1-6
SERVICE INFORMATION FOR EEPROM
POWER ON
It is possible at any function.
VFD "NO DISC" status (ex. It is possible at VFD "NO USB" status, too.)
This is an example.
Front `STOP' + Remote control " "
push same timing during 5s
FLD "OP00-....."
Move to appropriate position
And make changes
with RMC " , , , REPEAT" key.
Press STOP Key
VFD "WRITE OK"
Front `STOP' + Remote control " "
push same timing during 5s
VFD "E2P CLR"
Completed
1-7
PROGRAM DOWNLOAD GUIDE
1. AUDIO PROGRAM
Download program file name must be MICOM_CM8450_YYMMDDX.HEX
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds in the same way at USB1 function and USB2 function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device
2) Copy Firmware file to USB device.
NO USB
Insert USB device at USB function
SEARCH
MICOM UP
FINISH
Auto POWER OFF
1-8
2. CD PROGRAM
Download program file name must be HG580_CM8450_YYMMDDX.bin
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds in the same way at USB1 function and USB2 function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device
2) Copy Firmware file to USB device.
NO USB
Insert USB device at USB function
SEARCH
FIRMWARE
FINISH
Auto POWER OFF
1-9
3. EQ PROGRAM
Download program file name must be EQ_PRG.BIN
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds in the same way at USB1 function and USB2 function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device
2) Copy Firmware file to USB device.
NO USB
Insert USB device at USB function
SEARCH
EQ UP
FINISH
Auto POWER OFF
1-10
FOTA UPDATE
Step1 : App connecting Step2 : Step3 :
(Check FW version) Device version info Select update button
Step4 : Step5 : Step6 :
Download from CDN server Transfer FW FW Flash Writing
Step7 :
FOTA complete
1-11
SPECIFICATIONS
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