LG XB12 User manual

MODEL : XB12(XBS12V)
SERVICE MANUAL
P/NO : AFN35036924 SEPTEMBER, 2007
MINI HOME THEATER
SERVICE MANUAL
MODEL : XB12(XBS12V)
Website http://biz.lgservice.com
Internal Use Only
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL.

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
- 1-1 -
❍ SECTION 1. GENERAL
• SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
• ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
• LOCATION OF USERS CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
• SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
❍ SECTION 2. EXPLODED VIEWS
• CABINET AND MAIN FRAME SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
• SPEAKER EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
• PACKING ACCESSORY VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
❍ SECTION 3. ELECTRICAL
• ELECTICAL TROUBLESHOOTING GUIDE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
• WAVEFORMS OF MAJOR CHECK POINT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
• INTERNAL BLOCK DIAGRAM OF ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
• WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
• BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
• SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
• PRINTED CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39
❍ SECTION 4. REPLACEMENT PARTS LIST
• REPLACEMENT PARTS LIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
[CONTENTS]

- 1-2 -
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.
SERVICING PRECAUTIONS
SECTION 1. GENERAL
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
- 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 of humidity is high, where strong mag-
netism 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 (1MΩ)
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.
CLEARING MALFUNCTION
You can reset your unit to initial status if malfunction occur(button malfunction, display, etc.).
Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of
the volume knob for more than 3 seconds.
If you reset your unit, you must reenter all its settings(stations, clock, timer)
NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it.
2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord.

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only - 1-4 -
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components com-
monly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated cir-
cuits 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 com-
mercially 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 sur-
face 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 conduc-
tive 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 “DANGER-
OUS 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 SER-
VICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERA-
TURE.
ESD PRECAUTIONS

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
- 1-5 -
LOCATION OF USERS CONTROLS
FRONT
USB Memory, MP3
Player (or Memory Card
Reader, etc.)
Portable
Device
Portable
in cable
1. DISPLAY WINDOW
2. /[POWER FUNC. (function select)button
(DVD/CD,PORTABLE,FM,AM (optional),USB )
3. •STOP /MO./ ST. SET(■)
•PLAY /PAUSE (  / )
•TUNING (-) - Tuner
CD SKIP/ SCAN (
|
 )
•TUNING (+)- Tuner
CD SKIP/ SCAN ( 
|
)
•Volume control knob
4. PORTABLE IN Jack Using PORTABLE device
5. USB port
•USB Function
•Compatible Devices
•To Remove the USB from the unit
6. •TIMER
•CLOCK
7. DISC door
ALL
ALL

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only - 1-6 -
REMOTE CONTROL
2
3
4
116
15
14
13
9
10
11
12
5
6
7
8
RDS
RDS
PTYPTY
2
3
4
116
15
14
13
9
10
11
12
5
6
7
8
RDS
RDS
PTYPTY
1. POWER( )
2. FUNCTION SELECT
3. NUMERIC buttons (0- 9)
4. •EQ (EQUALIZER Effect)
•XDSS plus
5. •SOUND MODE
•AUDIO
•SUBTITLE
•RETURN ( )
6. SETUP
7. • /  /  / (left/right/up/down)
•PRESET -/+ (  / )
•TUN. -/+ (  / )
•SELECT/ ENTER
8. MENU
Accesses the menu on a DVD disc.
9. •PROG./MEMO.
•REPEAT
•REPEAT A-B
10. •STOP/MO./ST.( )
11. •CLEAR
•ZOOM
•MARKER - SEARCH
•SLEEP
•RDS,PTY - OPTIONAL
12.VOLUME -/+
13. •SKIP (
|
 / 
|
)
14. TITLE
15. DISPLAY
16.•MUTE( )

- 1-7 -
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SERVICE INFORMATION FOR EEPROM
1. Push Remote control '2' key and Front 'STOP' at the same time for 5 seconds.
•VFD: If released before 'Write OK' shows, EEPROM option does not change.
•LED: If released before 'UP OK' shows, EEPROM option does not change.
2. When entering in version setting mode, Option number can be changed by pushing left and right navigation
keys in circulation.
3. When entering in version setting mode, following option settings can be changed by pushing up or down
navigation keys.
4. When entering in version setting mode, all keys (except navigation key and enter key) works normal, but
FLD shows option setting info. continuously.
5. When Option setting is done, push ENTER key then FLD displays 'WRITE OK'.
6. Then, to change to E2P CLR status push Remote '2' key and Front 'STOP' at the same time, and set
power off, then option settings are done successfully.
NAME
OPT 0
OPT 1
OPT 2
OPT 3
OPT 4
HEX
02
48
C0
00
00
MODEL : XB12
2
3
4
116
15
14
13
9
10
11
12
5
6
7
8
RDS
RDS
PTY
PTY

- 1-8 - Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SPECIFICATIONS
General
Power supply Refer to the main label.
Power consumption Refer to the main label.
Net Weight 1.5 kg
External dimensions (WxHxD) 150 x 150 x 205 mm
Tuner/Amplifier
FM Tuning Range 87.5 - 108.0 MHz or 65 -74 MHz, 87.5 -108.0 MHz
Intermediate Frequency 10.7 MHz
Signal to Noise Ratio 60/55 dB (Mono/Stereo)
Frequency Response 140 - 10000 Hz
AM (optional) Tuning Range 522 - 1620 kHz or 520 - 1720 kHz
Intermediate Frequency 450 kHz
Signal to Noise Ratio 30 dB
Frequency Response 140 - 1800 Hz
Output Power Front: 5 W + 5 W (6, THD 10 %)
Frequency Response 30 - 20000 Hz
Signal-to-noise ratio 75 dB
Speaker Name(L/R) XBS12V
Type Bass Reflex1Way 1Speaker
Impedance 6 Ω
Net Dimensions (W x H x D) 150 X 150 X 150 mm
Net Weight 1.05 kg
Designs and specifications are subject to change without notice.

LGE Internal Use OnlyCopyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 2-1 - - 2-2 -
E
D
B
A
F
C
A
D
C
F
B
E
252
251
250
A43
450
FRONT
CABLE3
253
452
A03
265
450
A46
MAIN
290
291
267
450
453
A40
305
453
270
450
272
275
276
273 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.
CABLE2
CABLE1
450
255
CABINET AND MAIN FRAME SECTION
SECTION 2. EXPLODED VIEWS

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only - 2-3 - - 2-4 -

- 2-5 -
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MODEL: XBS12V
SPEAKER EXPLODED VIEW
A80A
A80B
851
A80
850
852
853
854
855
856
WIRE80

- 2-7 -
Copyright © 2007 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 (FM)
PACKING ACCESSORY VIEW

- 2-8 - Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

- 3-1 -
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
ELECTICAL TROUBLESHOOTING GUIDE
SECTION 3. ELECTRICAL
SMPS PART
No .5.6VA
YES
NO Replace the F901.
(Use the same Fuse)
NO Replace the BD901.
NO Replace the R901.
NO Is the D911 normal?
NO Replace the D953.
NO Replace the IC950.
NO
Check or Replace the
D911.
Is the F901
Normal?
YES
NO Replace the PC901.
YES
NO Replace the D952.
Is the D952
Normal?
YES
NO Replace the D955.
Is the D955
Normal?
YES
Power Line of Main
PCB is short.
Is the BD901
Normal?
YES
Is the R901
Normal?
YES
YES
YES
YES
IS the D953
normal?
Is there
about 2.5V at the
IC950 Pin1?
Is the PC901
normal?
Is Vcc
(9V - 18V) supplied
to IC911
Pin5?

- 3-2 - Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
YES
NO Check or Replace the
D953.
NO Check the CD CTL “H”
signal from µ-com.
YES
YES
Check or Replace the
IC951.
NO Check or Replace the
D952.
NO Check the P CTL “H”
signal from µ-com.
YES
Is the IC953
pin4 ‘H’?
YES
Check or Replace the
IC953.
No 3.3V
YES
NO Check or Replace the
D955.
NO Check the P CTL “H”
signal from µ-com.
Is the Vcc
(4.2V)supplied to
IC952 pin 1?
YES
YES
Check or Replace the
IC952.
No 5.0 V No 9V
YES
Is the Vcc
(5.6V) supplied to
IC951 pin 1?
Is the IC951
pin4 ‘H’?
Is the Vcc
(10.5V) supplied to
IC953 pin 1?
Is the IC952
pin4 ‘H’?

- 3-3 -
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
DOES 5V APPEAR IN
PN7102 PIN4?
YES
YES
NO CONNECTOR CHECK.
NO SMPS CHECK.
IC104 PIN49.
NO CHANGE IC104.
P-SENSE
P1702 PIN4 CHECK.
CHECK OUTPUT
FROM IC701.
YES
YES
YES
CHECK PATH FROM
IC701 TO IC702
CHECK IC701 PIN1
= 9V.
CHECK IC702 PIN3
= 10V.
AUDIO AB-NORMAL
CHECK INPUT FOR
IC702 (PIN4,12).
NO
CHECK OUTPUT JK701.
CHECK PATH FROM
IC702 TO JK701.
NO
NO
NO
CHECK SMPS.
CHECK SMPS.
NO
NO
CHECK OUTPUT IC702.

- 3-4 - Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
FUNCTION AUDIO AB-NORMAL
Portable.
YES
NO Check Signal
Input JK101.
YES
Check Output
IC701 (Pin12,17).
Check
Input for IC701
(Pin4,25).
Tuner.
YES
NO Check TU701
Pin3,5.
YES
Check Output
IC701 (Pin12,17).
Check
Input for IC701
(Pin5,24).
DVD/USB (For XB).
YES
NO ES8380
Pin117,123,124,1.
NO Check IC507
Pin9=5V.
YES
Check Output
IC507 Pin7,10.
YES
Check Input for
IC701 (Pin6,23).
YES
Check Output
IC701 (Pin12,17).
Check
Input for IC507
(Pin1,2,3,4).

- 3-5 -
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
CHECK IC104 VDD PIN9,36,45.
YES
YES
YES
YES
CHECK P-SENSE
SIGNAL.
CHECK X101
OSCILLATION.
REPLACE IC104.
NO REFER TO P-SENSE CHECK.
NO CHANGE X101.
NO CHECK RESET CIRCUIT.
NO CHECK P1702 PIN1.
MICOM IC104 TROUBLESHOOTING
CHECK IC701
PIN1=9V.
YES
YES
CHECK CONTROL
FUNCTION.
NO CHECK CLK DATA BY
CHANGE FUNCTION
FROM TUNER TO PORTABLE
NO CHANGE IC701.
NO CHECK SMPS.
IC701 TROUBLESHOOTING
CHECK IC104
PIN53 (RESET).
CHECK IC104
CLK DATA PIN14,15.

- 3-6 - Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
CHECK TU701
PIN2=9V.
YES
YES
CHECK
CE,DI,DO,CLK.
NO CHECK IC104.
NO CHECK SMPS.
FMAM TUNER CHECK
DVD & USB
CHECK TUNER
OPERATION.
Power On
YES
NO
YES YES
NO
YES
NO
NO
ES8380 operates
properly?
Check path between
Flash ROM and
ES8380.
Check path between
SDRAM and ES8380.
Check
Pin133,134,137,138,13
9,140 of ES8380.
NO Replace Flash ROM
(IC502).
NO Replace SDRAM
(IC503).
NO Replace ES8380
(IC501).
Show Logo? Does Flash
ROM operates
properly?
Does
SDRAM operates
properly?