LG MBD-K203Q User manual

MODEL : MBD-K203Q (FBS203V)
SERVICE MANUAL
P/NO : AFN542679853 MARCH, 2008
KARAOKE MINI
Hi-Fi SYSTEM
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL.
MODEL : MBD-K203Q (FBS203V)
Website http://biz.lgservice.com
Internal Use Only

1-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
[CONTENTS]
❍SECTION 1. GENERAL
• SERVICING PRECAUTIONS ................................................................................................ 1-2
• ESD PRECAUTIONS ............................................................................................................ 1-4
• SERVICE INFORMATION FOR EEPROM ............................................................................ 1-5
• PROGRM DOWNLOAD GUIDE ............................................................................................ 1-7
• SPECIFICATIONS .............................................................................................................. 1-11
❍SECTION 2. EXPLODED VIEWS
•CABINET AND MAIN FRAME SECTION.............................................................................. 2-1
•DECK MECHANISM EXPLODED VIEW ................................................................................ 2-3
•SPEAKER EXPLODED VIEW .............................................................................................. 2-5
•PACKING ACCESSORY VIEW.............................................................................................. 2-6
❍SECTION 3. ELECTRICAL PART
•TROUBLESHOOTING GUIDE
AUDIO PART TROUBLESHOOTING GUIDE ........................................................................ 3-1
DVD PART TROUBLESHOOTING GUIDE .......................................................................... 3-11
•WAVEFORMS OF MAJOR CHECK POINT ........................................................................ 3-19
•WIRING DIAGRAM .............................................................................................................. 3-25
•BLOCK DIAGRAM .............................................................................................................. 3-26
•CIRCUIT DIAGRAMS .......................................................................................................... 3-27
•INTERNAL BLOCK DIAGRAM OF IC ................................................................................ 3-47
•CIRCUIT VOLTAGE CHART ................................................................................................ 3-63
•PRINTED CIRCUIT DIARGAMS ........................................................................................ 3-67
❍SECTION 4. REPLACEMENT PARTS LIST ................................................................ 4-1

1-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
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.
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 cotton
swab should be used, taking care not to distort this.
6) Never attempt to disassemble the pick-up.
Spring by 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 fingers or other exposed skin.
Magnet
How to hold the pick-up
Conductive Sheet
Cotton swab
Pressure
Pressure
SECTION 1. GENERAL

1-3
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
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 of humidity is high, where strong magnet-
ism 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 (1M Ω)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent sta-
tic 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 Mohm) Conductive
Sheet
Resistor
(1 Mohm)
Armband

1-4 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
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 gener-
ate 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.
SAFETY PRECAUTIONS

1-5
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SERVICE INFORMATION FOR EEPROM (MICOM PART)
POWER ON
FLD no disc status
Remote control ‘2’+ Front ‘STOP’
push same timing during 5s
FLD ‘OP-0….
Use arrow key ( ) move
to appropriate position and make
changes
Press ENTER key once
FLD ‘write ok’
Remote control ‘2’+ Front ‘STOP’
push same timing
FLD display E2P CLR or EP CLR
Auto power off
MODEL : FBD203
NAME HEX
OPT 1 00
OPT 2 00
OPT 3 00
OPT 4 00
OPT 5 00
DETECT NEW EEPROM
(OPTION EDIT SCREEN)

1-6 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SERVICE INFORMATION FOR EEPROM (DVD PART)
POWER ON
DVD LOGO Status (NO Disk status)
Remote control
Pause key-->1-->4-->7-->2 in order.
Press number 0~9, Press character
A~F (1~6 for a while)
Use arrow key ( ) to
move to appropriate position and
make changes
Press pause key once
Change will be applied when power
OFF-->ON.
NAME
OPT 1
OPT 2
OPT 3
OPT 4
OPT 5
OPT 6
OPT 7
OPT 8
OPT 9
OPT A
OPT B
OPT C
OPT D
OPT E
OPT F
OPT G
HEX
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
DETECT NEW EEPROM
(OPTION EDIT SCREEN)

1-7
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
PROGRM DOWNLOAD GUIDE
• AUDIO USB DOWNLOAD GUIDE
The name of the program file to download is FBD203_date.hex.
- At some PCs with the security program (Water Wall) installed, store it at the USB device, disable
the security protection, and download it to the set.
Note) Do not perform any other work such as disconnecting the USB device, switching to the
other Function and turning off the power while downloading it to the set.
The USB device should be disconnected after completing the download.
1. When the USB device is inserted at the USB function a after a while TV screen is displayed on the
as following figure.

1-8 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. The message “Upgrade”is displayed while downloading.
3. The power is automatically turned off when downloading is completed.

1-9
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
•DVD USB DOWN LOAD GUIDE
The program file to download should be named as BANK30.ROM.
- The downloaded file should be modified as BANK30.ROM to use.
- At some PCs with the security program (Water Wall) installed, store BANK30.ROM at the USB
device, disable the security protection, and download it to the set.
- After safely storing BANK30. ROM at the USB device, perform the following steps.
Note) Do not perform any other work such as disconnecting the USB device, switching to the
other Function and turning off the power while downloading it to the set.
1. When the USB device is inserted at the USB functiona after a while TV screen is displayed on the
as following figure.
2. When downloading is completed, the message “Completed”is displayed at the top left of the TV screen
as shown at Figure(1).
If the message “NO USB”is displayed as shown at Figure(2), downloading is completed.
FIG.1
FIG.2

1-10 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. Turn on the power, press the SETUP button of the remote controller at the USB FUNCTION.
When the SETUP window is displayed on the screen, move down once to select the DISPLAY menu.
Go to the TV Aspect at the right menu, move to “16:9”, enter “1397139”by using the numeric key of the
remote controller, and then press the Enter key.
Then, the System Information screen is displayed as shown inthe following figure. If not, retry the steps
at the above.
4. When Step 3 is completed, press the PAUSE KEY of the remote controller.
5. Disconnect the power code, and reconnect it after 5 seconds to complete downloading.
7. When the power is turned on again, the language selection menu is initially displayed.
After selecting the desired language, press the SELECT/ENTER.
Left Right
Down

1-11
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SPECIFICATIONS
General
Power supply Refer to main label.
Power consumption Refer to main label.
Net Weight 3.42 kg
External dimensions (W x H x D) 330 x 138.5x 252.4 mm
Operating conditions Temperature: 5°C to 35°C, Operation status: Horizontal
Operating humidity 5% to 85%
Tuner
FM Tuning Range 87.5 - 108.0 MHz or 65.0 - 74.0 MHz, 87.5 - 108.0 MHz
Intermediate Frequency 10.7 MHz
AM Tuning Range 522 - 1,620 kHz or 520 - 1,720 kHz
Intermediate Frequency 450 kHz
Amplifier
OUTPUT POWER 100 W + 100 W (4Ω, THD 0.5%) : MBD- K203Q
50 W + 50 W( 4Ω, THD 0.5%) : MBD- K103Q
Stereo Mode 100 W + 100 W (4Ω, THD 0.5%) : MBD- K203Q
50 W + 50 W( 4Ω, THD 0.5%) : MBD- K103Q
Frequency Response 40 - 20000Hz
Signal- to- noise ratio 75dB
DVD/ VCD/ CD player
Frequency response (audio) 40 - 20000 Hz
Signal- to- noise ratio (audio) More than 75 dB (1 kHz)
Signal- to- noise ratio (video) More than 55 dB (1 kHz)
Dynamic range (audio) More than 80 dB
Video output 1.0 V (p- p), 75 Ω
Component Video output (Y) 1.0 V (p- p), 75 Ω
Speakers
FBS203V
Type 2Way 2Speaker
Impedance 4 Ω
Rated Input Power 100 W
Max. Input Power 200W
Net Dimensions (W x H x D) 165 X 341 X 261 mm
Net Weight 4.48 kg
Designs and specifications are subject to change without pior notice.

1-12 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

B
E
A
F
D
FG
G
B
D
A
C
E
254 253 453
260
A26
255
453
256
453
453
257
A42
A43
A46
A47
258 453
CABLE2
453
259
FRONT
MIC
273
471
471
453
SMPS
SCART
MAIN
453
250
453
300
453
453
272
A44
465
270
271
271
H
I
CABLE3
H
I
271
C
CABLE1
2-1 2-2
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
• CABINET AND MAIN FRAME SECTION
SECTION 2. EXPLODED VIEWS
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.

2-3 2-4 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
DECK MECHANISM EXPLODED VIEW
1. DECK MECHANISM SECTION (DP-10)
A26
439 018
014
001
002
003
A01
A02
020
013
017
012
019
015
435
012
432
030 010
439
024
431
435
025
036
430
021
A03
026
440
016
015A
012A
012A
015B

2-5
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
• FRONT SPEAKER (FBS203V)
SPEAKER EXPLODED VIEW
851
852
A81A
A81R
A81L
A80R
A80L
853
854
855
856
860
861
859
863
862
860
865L
865R
857
858

2-6 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
808 Battery
900 Remote Control
801 Instruction Ass'y
803 Packing
803 Packing
804 Bag
802 Box
825 Antenna
824 Antenna Loop
Micro Phone
827
801S Song Book
Plug Ass'y, 1Way
811
832 DISC
• PACKING ACCESSORY VIEW

3-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. MICOM PART CHECK I
OK OK
NO
NO NO Replace the
related parts.
Check if output voltage
of IC101 KIA7042 is
4.3V.
YES
YES
YES YES
YES YES
Check IC100
LC87F5NC8A 4 PIN
power.
YES
Refer to SMPS
troubleshooting.
MICOM PART
HECK I
Check
CN101 6PIN
P-SENS.
NO
Check
power of both
terminals of IC101
KIA7042
Check if
IC101 KIA7042
input is over 5V.
Check the
related part of IC101
KIA7042.
AUDIO ELECTRICAL TROUBLESHOOTING GUIDE
SECTION 3. ELECTRICAL PART

3-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. MICOM PART CHECK II
NO
YES
YES
YES
YES
YES
Refer to SMPS
Troubleshooting.
NO Check D101 RS1G
output is working on 5V.
Check IC103 8PIN IC100
14,55,89 PIN 5V
YES
YES
OK
YES
YES
Check Q102 COLLECTOR
YES
Check the related part.
Replace the related parts.
Check the working condition
X100:32.768kHz
X101:9.8304MHz
Check CN101 5PIN 5.6V
Check power
of both terminals of D101
RS1G.
YES
NO
Check Q10
EMITTER 5V and
COLLECTOR 5V
Check the related part
MICOM PART CHECK II
NO
NO
Replace the related parts.
Check Q102 BASE
PIN 0.6V HIGH
NO Check output power of IC101
KIA7042 is over 4.3V.
Check the
related part.
NO Replace the related parts.
OK
YES
OK
YES
OK

3-3
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. IC103 S-24CS16A01 PART CHECK
YES
YES
YES
YES
81 PIN DATA 82 PIN CLK
Check the related part.
NO
Check MICOM power 5V
CHECK IC100 LC87F5NC8A
81,82 PIN
NO Replace the related parts.
NO Refer to micom
troubleshooting.
OK OK