LG CJ44 User manual

SERVICE MANUAL
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
Internal Use Only
JANUARY, 2017
MODEL: CJ44 (CJ44, CJS45F)
MODEL: CJ44
(CJ44, CJS45F)
Mini Hi-Fi System
P/NO : AFN77612119

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
1. HIDDEN KEY MODE TABLE.................................................................................................................... 1-6
2. HIDDEN KEY MODE DESCRIPTION....................................................................................................... 1-7
SERVICE INFORMATION FOR EEPROM........................................................................................................ 1-9
PROGRAM DOWNLOAD GUIDE.................................................................................................................... 1-10
FOTA UPDATE STEP USING BT APP .......................................................................................................... 1-12
SPECIFICATIONS ........................................................................................................................................... 1-14
1-2

1-3
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.
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.
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.
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.
Storage in conductive bag Drop impact
NEVER look directly at the laser beam, and don’t allow
contact with fingers or other exposed skin.
Magnet
How to hold the pick-up
Conductive Sheet
Cotton swab
Pressure
Pressure
SERVICING PRECAUTIONS

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.
Resistor
(1 M)Conductive
Sheet
Resistor
(1 M)
Armband
1-4

1-5
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.
ESD PRECAUTIONS

1-6
HIDDEN MODE ENTRANCE KEY(Audio) EXIT KEY
Version Check Front ‘Stop’
+ Remote Control Key ‘Play’ for 5s Remote Control Key ‘Play’ for 1.5s
EEPROM INITIAL Front ‘Stop’
+ Remote Control Key ‘ ‘ for 5s Auto exit
Option EDIT Front ‘Stop’
+ Remote Control Key ‘ ‘ for 5s Front ‘Stop’ + Remote Control Key ‘ ‘
APD Test Display Front ‘Stop’
+ Remote Control Key ‘3’ for 5s Auto exit
Disc Lock On/Off Front ‘Stop’ +
Remote Control Key ‘Stop’ for 5s
Front ‘Stop’
+ Remote Control Key ‘Stop’ for 5s
Power Disc Lock On/Off Front ‘Stop’ + Front ‘Open’ for 5s Front ‘Stop’ + Front ‘Open’ for 5s
Demo ALL Key Lock Front ‘Stop’
+ Remote Control Key ‘9’ for 5s
Front ‘Stop’
+ Remote Control Key ‘9’ for 5s
BT Auto Power On/Off Front/Remote Control Key ‘Power’ for 5s Front/Remote Control Key ‘Power’
SET Power Off
ChildSafe On/Off Volume 0(Min) + Front ‘OK’ for 3s Volume 0(Min) + Front ‘OK’ for 3s
Measure Front ‘Stop’
+ Remote Control Key ‘1’ for 5s Remote Control Key ‘SOUND EFFECT’
1. HIDDEN KEY MODE TABLE
HIDDEN KEY MODE
//

1-7
2. HIDDEN KEY MODE DESCRIPTION
2-1. Version Check
- Function : Version Check.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘Play’ for 5s.
- Exit Key : Remote Control Key ‘Play’ for 1.5s.
- Operation explanation : Remote Control Key OR .
VFD Display (Example) Result
MCS Version
MICOM Version
OPTION Version
DEMO Version
DJ PRO Version
EQ Version
EQ Check sum Version
2-2. EEPROM Initial
- Function : Initialize data stored in EEPROM and BACKUP RAM data.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘ ‘ for 5s.
- Exit Key : Auto exit.
- Explanation : ‘E2P CLR’ is displayed on the VPD and turn off the power automatically.
2-3. OPTION EDIT (EEPROM)
- Refer to the page 00.
2-4. APD Test Display
- Function : Auto Power Down timer is displayed on VFD.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘3’ for 5s.
- Exit Key : Auto Exit.
- Explanation : display APD Timer HH=(hour) MM=(min), SS=(sec).

1-8
2-5. Disc Lock On/Off
- Function : Lock Open Key.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘Stop’ for 5s.
- Exit Key : Front ‘Stop’ + Remote Control Key ‘Stop’ for 5s.
- Operation Explain : Open Key Block ‘LOCKED’.
2-6. Power Disc Lock On/Off
- Function : Lock Power / Open / Front Volume Key.
- Entrance Key : Front ‘Stop’ + Front ‘Open’ for 5s.
- Exit Key : Front ‘Stop’ + Front ‘Open’ for 5s.
2-7. Demo All Key Lock
- Function : All key is blocked on Demo Mode.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘9’ for 5s.
- Exit Key : Front ‘Stop’ + Remote Control Key ‘9’ for 5s.
- Operation Key : In demo mode, all key blocks.
(only the volume key is effective when All Key Lock is enabled.)
To release Demo Mode, it is available after All Key Lock Off.
2-8. BT Auto Power On/Off
- Function : Ability to disable BT Auto Power On function by network shutdown regulation.
- Entrance Key : Front/Remote Control Key ‘Power’ for 5s.
- Exit Key : SET Power Off with Front / Remote Control Key ‘Power’.
2-9. ChildSafe On/Off
- Function : Power off Fade-in to previous volume.
- Entrance Key : Volume 0(Min) + Front ‘OK’ for 3s.
- Exit Key : Volume 0(Min) + Front ‘OK’ for 3s.
2-10. Measure
- Function : Change to EQ for Measure mode,
Down algorithm operation Disable,
Change to output setting value for measure mode.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘1’ for 5s
- Exit Key : Remote Control Key ‘SOUND EFFECT’

POWER ON
VFD “NO DISC” status
It is possible at any function.
(ex. It is possible at VFD “NO USB” status, too.)
This is an example.
Front ‘Stop’ + Remote control ‘ ’
push same timing during 5 s
FLD “OP00-…..”
Move to appropriate position
And make changes with remote control
“ , , , REPEAT” key.
Press ‘Stop’ Key
VFD “WRITE OK”
Front ‘Stop’ + Remote control ‘ ’
push same timing during 5 s
VFD “E2P CLR”
Completed
1-9
SERVICE INFORMATION FOR EEPROM
/
NAME
OPT0
OPT1
OPT2
OPT3
OPT4
OPT5
OPT6
OPT7
OPT8
OPT9
OPT10
OPT11
OPT12
OPT13
OPT14
DETECT NEW EEPROM
(OPTION EDIT SCREEN)
HEX
01(LGEAP)/11(LGERA)
31
2D
26(LGEAP)/22(LGERA)
19
00
00
43
4A
34
00
00
00
00
00

1. CD PROGRAM
Download program file name must be HG740_CJ44_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
MICOM UP
FINISH
AUTO POWER OFF
1-10
PROGRAM DOWNLOAD GUIDE

2. EQ & DEMO 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
EQDEMOUP
FINISH
AUTO POWER OFF
1-11

1-12
FOTA UPDATE STEP USING BT APP
Step1 : App connecting
(Check FW version)
After connecting the BT App with SET,
the user could find the “Device Version info” on
Setting tab.
Step3 : Select update button
When touch the “Update” button, user could
update the SET firmware using FOTA.
Step2 : Device version info
When touch the “Device Version info” button,
user could find the current and latest SET
version on pop-up menu.
Step4 : Confirm update
Select the OK button on the caution message.

1-13
Step5 : Download from CDN server
1st step is download from CDN server to
smart phone. The progress bar is displayed
on BT App.
Step7 : FW Flash Writing Step8 : FOTA complete
After completed the download from the smart
phone, the SET overwrite the firmware to flash
memory.
When finishing the flash memory writing, pop-up
message about finish is displayed and the SET
auto power off.
Step6 : Transfer FW
After completed the download from server,
smart phone start to transfer the firmware to the
SET. The progress bar is displayed on BT App.

SPECIFICATIONS
1-14
•GENERAL
Power requirements Refer to the main label on the unit.
Power consumption Refer to the main label on the unit.
Networked standby : 0.5 W
(If all network ports are activated.)
Dimensions (W x H x D) Approx. 350 mm x 163 mm x 251 mm
Operating temperature 5 °C to 35 °C (41 °F to 95 °F)
Operating humidity 60 %
•INPUTS
Analog audio in (AUX IN) 1.0 Vrms (1 kHz, 0 dB), 75 Ω, RCA jack (L, R)
Portable in (PORT.IN) 500 mVrms (3.5 mm stereo jack) x 1
Microphone (MIC) Sensitivity 20 mV (1 kHz), 6.3 mm jack x 1
•TUNER
FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz
•SYSTEM
Frequency Response 100 to 20,000 Hz
Signal-to-noise ratio More than 75 dB
Dynamic range More than 75 dB
Bus Power Supply (USB) 5 V 500 mA
•AMPLIFIER (RMS Output power)
Total 720 W RMS
Front 240 W RMS X 2 (3 Ωat 1 kHz, 20 % THD)
Subwoofer 240 W RMS (3 Ωat 60 Hz, 20 % THD)
•FRONT SPEAKER
Type 2 Way 2 Speaker
Impedance 3 Ω
Rated Input Power 240 W RMS
Max. Input power 480 W RMS
Net Dimensions (W x H x D) Approx. 266 mm x 314 mm x 234 mm
•Design and specifications are subject to change without notice.

SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS ......................................................................................................................................... 2-3
1. CABINET AND MAIN FRAME SECTION ................................................................................................. 2-3
2. PACKING ACCESSORY SECTION ......................................................................................................... 2-7
3. SPEAKER SECTION ................................................................................................................................ 2-8
DISASSEMBLY INSTRUCTIONS................................................................................................................... 2-9
1. Case Top................................................................................................................................................... 2-9
2. Bracket ...................................................................................................................................................... 2-9
3. Panel Rear .............................................................................................................................................. 2-10
4. MAIN Board & SMPS Board ................................................................................................................... 2-11
5. Main PCB & SMPS PCB......................................................................................................................... 2-12
6. Panel PCB & Multi Knob......................................................................................................................... 2-13
7. Bracket SMPS......................................................................................................................................... 2-14
8. MD........................................................................................................................................................... 2-14
2-1

2-2

D
A
B
MIC
262
BT
265
265
252
252
A42
H300
498
A52
C
F
CABLE2
A00
254
254
443
E
FRONT
A43
266
443
443
274
443
463
443
443
264
443
443
D
E
F
G
C
B
A
A47
273
A46
443
MAIN
SMPS
443
H
CABLE1
A45
272
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION
NOTES) THE EXCLAMATION POINT WITHIN AN
EQUILATERAL TRIANGLE IS INTENDED
TO ALERT THE SERVICE PERSONNEL
TO THE PRESENCE OF IMPORTANT
SAFETY INFORMATION IN SERVICE
LITERATURE.
2-42-3

2-62-5

2-7
802 Box
804 Bag
Packing803
900 Remote control
808 Battries
825 FM antenna
801 Owner’s manual
2. PACKING ACCESSORY SECTION
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