LG LAS350B Service Manual

SERVICE MANUAL

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.

Internal Use Only

Website http://biz.lgservice.com

JULY, 2015

MODEL: LAS350B (LAS350B, S35A1-W)

MODEL: LAS350B

(LAS350B, S35A1-W)

Sound Bar

P/NO : AFN77277006

CONTENTS

SECTION 1 ........ GENERAL

SECTION 2 ........ CABINET & MAIN CHASSIS

SECTION 3 ........ ELECTRICAL

SECTION 4 ........ REPLACEMENT PARTS LIST

1-1

SECTION 1

GENERAL

CONTENTS

ESD PRECAUTIONS ......................................................................................................................................... 1-3

HIDDEN KEY MODE ......................................................................................................................................... 1-4

SERVICE INFORMATION FOR EEPROM ........................................................................................................ 1-4

MCS / EQ HIDDEN KEY GUIDE ....................................................................................................................... 1-5

MCS / EQ PROGRAM UPDATE GUIDE ........................................................................................................... 1-5

SPECIFICATIONS ............................................................................................................................................. 1-6

1-2

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.

1-3

HIDDEN KEY MODE

HIDDEN MODE KEYS

USB MODE ENTRY/UPDATE Main set ‘-’ (Volume) + Remote control ‘MUTE’

EEPROM EDIT Main set ‘-’ (Volume) + Remote control ‘OPTICAL’

EEPROM CLEAR (Initialize) Main set ‘-’ (Volume) + Remote control ‘Treble/Bass’

VERSION CHECK Main set ‘-’ (Volume) + Remote control ‘LG TV’

up Sound Effect

down NIGHT

right F.Skip (Right)

left B.Skip (Left)

enter AV Sync

SERVICE INFORMATION FOR EEPROM

POWER ON

OPT Status

Main set ‘-’ (Volume) + Remote control ‘OPTICAL’

VFD " OPT.."

Use arrow key [Sound Effect, NIGHT, F.Skip (Right), B.Skip (Left)] to move to appropriate position and make changes

Remote control ‘AV SYNC’

Display VFD “E2P CLR”

Power off automatically

Power cord unplug

1-4

MCS / EQ HIDDEN KEY GUIDE

1. Version & Option Check

1) Power on.

2) Press main set “-” (volume -) key and remote control "LG TV" key during 3 seconds.

3) Check MCS version.
Ex) P1412120

4) Press remote control “F.Skip (Right)” 1 time.
Check EQ version.
Ex) Q1412020

5) Press remote control “F.Skip (Right)” 1 time.
Check option.
Ex) 10010000

2. Initialize

1) Power on.

2) Press main set “-” (volume -) key and remote control “Treble/Bass” during 3 seconds.

3) Display VFD “E2P CLR”.

4) Power off automatically.

5) Power cord unplug.

MCS / EQ PROGRAM UPDATE GUIDE

1. Preparation

- Remote control.

- Do format USB Memory to FAT32 File system.

- USB : Update fi le exist only in the USB Memory stick.
Ex ) LAS350B :
MCS  E:￦LAS350B_FW_201412221.bin (if USB driver is E:￦)
EQ  E:￦EQ_PRG_LAS350B_141219_0_4112.bin (if USB driver is E:￦)

2. Update

1) Power on.

2) Change the USB function. [Main set ‘-’ (Volume) + Remote control ‘MUTE’]

3) Insert USB.

4) Display in VFD.
MCS : “MCS UP”  “FINISH”  Power off.
EQ : “EQ UP”  “FINISH”  Power off.

5) Loading is shown while updating.
Never remove USB or AC cord.

6) After update fi nish, show FINISH in VFD and power of automatically.

7) Power cord un-plug.

1-5

SPECIFICATIONS

• 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) 880 mm x 59 mm x 90 mm
Net Weight (Approx.) 1.9 kg
Operating temperature 5 °C to 35 °C
Operating humidity 5 % to 90 %

• INPUT/OUTPUT

OPT. IN 3 V (p-p), Optical jack x 1
PORT. IN 0.5 Vrms (3.5 mm stereo jack) x 1
Available Digital Input Audio
Sampling Frequency 32 kHz, 44.1 kHz, 48 kHz, 96 kHz

• AMPLIFIER

Total 120 W
Front 25 W x 2 (6 Ω at 1 kHz)
Subwoofer 70 W (4 Ω at 100 Hz)
THD 10 %

• SUBWOOFER (S35A1-W)

Type 1 Way 1 Speaker
Impedance 4 Ω
Rated Input Power 70 W
Max. Input Power 140 W
Dimensions (W x H x D) 156 mm x 300 mm x 288 mm
Net Weight (Approx.) 2.9 kg

• BLUETOOTH

Codec SBC

• Designs and specifications are subject to change without prior notice.

1-6

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

EXPLODED VIEWS ........................................................................................................................................... 2-3

1. MAIN SET SECTION ................................................................................................................................ 2-3

2. SUBWOOFER SECTION .......................................................................................................................... 2-5

3. PACKING ACCESSORY SECTION ......................................................................................................... 2-7

2-1

2-2

D

C

503

251

A42

262

B/T

KEY

CABLE5

CABLE6

CABLE7

CABLE3

CABLE8

CABLE7

CABLE6

506

257

A53

258

A54

258

504

257

506

A45

504

503

503

263

506

266

504

504

505

259

A52

264

504

K

USB

DISPLAY

MAIN

SMPS

B

I

G

H

A

B

E

F

H

C

D

F

G

E

J

J

A

K

I

CABLE2

CABLE1

CABLE4

A47

505

504

A43

A46

505

505

A48

A55

265

256

256

300

EXPLODED VIEWS

1. MAIN SET 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. SUBWOOFER SECTION

A900

3. PACKING ACCESSORY SECTION

801 Owner’s manual 835 Wall bracket

806 Optical cable 836 Screws

808 Batteries 837 Cover foot

900 Remote control 826 Filter, Ferrite Core

803 Packing, Main

804 Bag

802 Box

2-8

SECTION 3

ELECTRICAL

CONTENTS

ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2

1. NO POWER PROBLEM (PVDD) ............................................................................................................ 3-2

2. POWER ON ERROR .............................................................................................................................. 3-3

3. NO SOUND (PORTABLE FUNCTION) .................................................................................................. 3-4

4. NO BLUETOOTH .................................................................................................................................... 3-5

5. NO SOUND (OPTICAL) .......................................................................................................................... 3-6

ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................... 3-7

1. POWER SUPPLY CIRCUIT .................................................................................................................... 3-7

2. FRONT CIRCUIT .................................................................................................................................... 3-8

3. TEST & DEBUG FLOW ........................................................................................................................ 3-10

4. AMP PROTECTION .............................................................................................................................. 3-13

WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-14

1. CRYSTAL .............................................................................................................................................. 3-14

2. FLASH MEMORY ................................................................................................................................. 3-15

3. TACT KEY ............................................................................................................................................. 3-16

4. USB ....................................................................................................................................................... 3-17

5. REMOTE CONTROL ............................................................................................................................ 3-18

6. OPTICAL ............................................................................................................................................... 3-19

7. PORTABLE ........................................................................................................................................... 3-20

8. AUDIO PWM ......................................................................................................................................... 3-21

9. AUDIO AMP .......................................................................................................................................... 3-23

WIRING DIAGRAM .......................................................................................................................................... 3-25

BLOCK DIAGRAM .......................................................................................................................................... 3-27

CIRCUIT DIAGRAMS ...................................................................................................................................... 3-29

1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-29

2. MAIN - DSP CIRCUIT DIAGRAM ......................................................................................................... 3-31

3. MAIN - POWER CIRCUIT DIAGRAM ................................................................................................... 3-33

4. MAIN - PWM & AMP CIRCUIT DIAGRAM ........................................................................................... 3-35

5. DISPLAY/ KEY/ USB CIRCUIT DIAGRAM ........................................................................................... 3-37

CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-39

PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-41

1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-41

2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-43

3. DISPLAY P. C. BOARD DIAGRAM ...................................................................................................... 3-45

4. KEY P. C. BOARD DIAGRAM .............................................................................................................. 3-45

5. USB P. C. BOARD DIAGRAM .............................................................................................................. 3-45

3-1

ONE POINT REPAIR GUIDE

CON402 pin1, 2

1. NO POWER PROBLEM (PVDD)

No power problem occurs when you power on the unit

1-1. Solution

Replace SMPS board.

1-2. How to troubleshoot (Countermeasure)

1) Check the PVDD voltage 32 V at pin1, 2.
When you check the no power at this point, then replace SMPS board.

1-3. Service hint (Any picture / Remark)

CON402 pin1, 2

R463

1K

< MAIN board top view >

3-2

ONE POINT REPAIR GUIDE

L405

L427

EC405

IC402 pin1

IC404 pin1

IC406 pin E

2. POWER ON ERROR

No display or Not working.

2-1. IC402

1) Check 3.3 VA at L405.

2) If 3.3 VA is not checked at the point, then find 32 V at pin1 of IC402.

3) 1), 2) is NG.  Replace IC402.

L405

IC402 pin1

< MAIN board top view >

2-2. IC404

1) Check 12 VA at L427.

2) If 12 VA is not checked at the point, then find 32 V at pin1 of IC404.

3) 1), 2) is NG.  Replace IC404.

L427

IC404 pin1

< MAIN board top view >

2-3. IC406

1) Check 5 VA at EC405.

2) If 5 VA is not checked at the point, then find 12 V at pin E of IC406.

3) 1), 2) is NG.  Replace IC406.

EC405

IC406 pin E

< MAIN board top view >

3-3

ONE POINT REPAIR GUIDE

JK504

L501

L502

IC400

3. NO SOUND (PORTABLE FUNCTION)

3-1. Solution

Replace IC400 or portable jack (JK504).

3-2. How to troubleshoot (Countermeasure)

1) Please check the soldering status of JK504

2) Please check L501, L502 (PORT_L, PORT_R signal) of portable jack (JK504).
If you cannot find input signal, replace JK504.

3) If you can find input signal, check pin13, 14 of IC400.

4) If you can’t find signal at pin13, 14 of IC400, replace IC400.

3-3. Service hint (Any picture / Remark)

JK504

L501

L502

< USB board bottom view >

IC400

< MAIN board top view >

3-4

ONE POINT REPAIR GUIDE

IC101

C174

CON102

4. NO BLUETOOTH

4-1. Solution

Replace IC101 on MAIN board.(No 3.3 V)

4-2. How to troubleshoot (Countermeasure)

1)

Please check externally status of Bluetooth cable connection on your eyes.(at CON102 and Bluetooth module)

2) Please check 3.3 V of 3.3VA (at C174).
If 3.3 V is OK at L509, please check BT_SDA, BT_SCL, BT_RST (pin53, 51, 25) of IC101
and BT_RX, BT_TX (pin29, 27).
If you have no signal, please replace IC101.

4-3. Service hint (Any picture / Remark)

CON102

C174

IC101

< MAIN board top view >

3-5

ONE POINT REPAIR GUIDE

L505

R428

IC401

5. NO SOUND (OPTICAL)

5-1. Solution

Replace IC401 on MAIN board.

5-2. How to troubleshoot (Countermeasure)

1) Please check 3.3 V of 3.3 VA at L505 in USB board
If you can check 3.3 V, please confirm OPT_DET signal (R428) in MAIN board when optical mode.

2) In spite of process 1), set has abnormal output, then replace IC401.

9
8
4

R

5

L

7
6
123

R317

JK504

0R

100PF

R316

NC

1

OUT

2

GND

3

VCC

JK502

CON502

P_R
P_L
P_DET
P_GND
SPDIF
GND
5V
D+
D­GND

L501

600RH

L502

600RH

L503

600RH

L504

3

D503

1

2

3

4

5

6

7

8

R504

9

0R

10

KDS226

1

2

R503

0R

L506

0R

L507

0R

600RH

100PF

C501

100PF

C502

600RH

C503

R318
100R

C317

C505

C506

10PF

100PF

100NF

C316

10NF

C504
100R

L505

L508

600RH

5-3. Service hint (Any picture / Remark)

< USB board bottom view >

L505

IC401

R428

< MAIN board top view >

3-6

ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER SUPPLY CIRCUIT

INSERT POWER CORD.

Standby LED is normal?

YES

Power on.

YES

Is power on?

YES

Does it output audio?

YES

OK

NO

NO

NO

Check power supply circuit.

Check circuit.

Check audio circuit.

3-7

ELECTRICAL TROUBLESHOOTING GUIDE

2. FRONT CIRCUIT

Is the Digitron on correctly?

YES

POWER ON.

YES

LED DISPLAY

correctly?

YES

Check if all

buttons are ok?

YES YES

Check if the remote

control is ok?

YES

NO

NO

NO

NO

Refer to SMPS part.

Check if

CON301 is ok?

YES

1

2

Check if the front

power is ok?

Check if IC301 is ok?

NO

NO

NO

Reconnect it.

Check power supply circuit.

YES

Refer to SMPS part.

Check pattern and resolderingFront B/D ok.

3-8

ELECTRICAL TROUBLESHOOTING GUIDE

FRONT CIRCUIT

1

if the power part of the front

Check

is ok?

YES

Check if CON303 is ok?

YES

Check if R306~R309 ok?

YES

Refer to MICOM circuit.

2

NO

NO

NO

Refer to power(SMPS).

Reconnect it.

Replace R306~R309.

if thepower part of the front

Check

is ok?

YES

Check if the remote

control waveform of CON301

pin3 is ok?

YES

Check if REM

voltage is ok(3.3 V)?

YES

Resolder or Replace IR301.

NO

NO

NO

Refer to power(SMPS).

Refer to MICOM circuit.

Check REM circuit

3-9

ELECTRICAL TROUBLESHOOTING GUIDE

3. TEST & DEBUG FLOW

TEST.

AC voltage Power PCBA (110 V

Check the

or 220 V).

YES

Switch on the Power PCBA.

YES

Are the

DC Voltage outputs OK? (32 V)

YES

Are 3.3 V and

5 V DC outputs normal on main

PCBA?

YES

Update

FLASH successfully?

NO

NO

NO

NO

Check the POWER PART.

Refer to SMPS part.

Check the POWER PART.

1. Check 24 MHz system clock.

2. Check system reset circuit.

3. Check FLASH R/W enable signal PRD, RWR.

4. Check FLASH Memory related circuit.

YES

A

Replace FLASH.

NO

3-10

ELECTRICAL TROUBLESHOOTING GUIDE

A

YES

Power On.

YES

Show HELLO.

YES

Connect a bluetooth device,

music is played.

YES

Does it output

audio?

YES

Show

the bluetooth name

NO

NO

Flash

Memory operates

properly?

YES

SDRAM

works properly?

YES

Check if CON104 is ok?

YES

Check if Front circuit.

Check

if CON102 is ok?

NO

NO

NO

NO

Check connection lines

between FLASH & MCL3730

and the FLASH access time

whether is suitable or not.

Check connection lines
between SDRAM(IC102) &
MCL3730 and the SDRAM

is damaged.

Reconnect it.

Reconnect it.

B

YES

YES

Replace the bluetooth module

NO

Check the AMP part

3-11

ELECTRICAL TROUBLESHOOTING GUIDE

B

YES

Function transformation

to OPT

YES

Does it output

audio?

YES

Function transformation

to PORT Insert AUDIO line

YES

Does it output

audio?

YES

NO

NO

Check the OPT
the input signal

YES

Check if JK502

voltage is ok(3.3 V)?

YES

Replace the JK502(OPT)

Check if MCL3730

pin4 “H”

YES

NO

NO

NO

Check the OPT line,

Changing the OPT Equipment

Check if CON502 is ok?

Check if JK504 det.pin

voltage is ok(0 V)?

YES

TEST END.

Check if IC400 pin13, 14

Is there a signal input?

YES

Check if IC400 pin3, 4

voltage is ok(3.3 V, 5 V)?

YES

Check if IC400 pin6~9

(MCLK, LRCK, DATA, BCK)

YES

Replace the IC400

3-12

NO

NO

Replace the JK504

Check the POWER PART.

ELECTRICAL TROUBLESHOOTING GUIDE

4. AMP PROTECTION

“S-PROTEC” appears on the FLD.

YES

After unplug power cord, connect again.

YES

Power on.

YES

Display, automatic standby

“Goodbye”

YES

Is the IC701 pin16, 17

“LOW” signal(0 V)?

YES

Is the AMP IC Power

12 V, 32 V normal?

YES

Replace TI AMP IC(IC701, IC702)

NO

NO

NO

OK.

Replace IC701.

12 V: CHECK Q701 Part.

32 V: CHECK SMPS Part.

3-13

1. CRYSTAL

1

WAVEFORMS OF MAJOR CHECK POINT

1

FIG 1-1. X101 (24 MHz)

2

2

2

FIG 1-2. X400, X401 (24.576 MHz)

3-14

2. FLASH MEMORY

VCC

3

4

4

CS#

CLK

5

DO

6

3

5

6

FIG 2. VCC, CS#, CLK, DO

3-15

3. TACT KEY

7 8

1 ~ 1.13 V

FIG 3-1. Press VOL + FIG 3-2. Press VOL -

9

0.72 ~ 0.82 V

10

0.424 ~ 0.485 V

FIG 3-3. Press FUN.KEY

0 V

7 8
9 10

C311

FIG 3-4. Press POWER KEY

3-16

4. USB

11

12

FIG 4-1. USB_5V

C475

EC405

100uF/16V

11

13

FIG 4-2. USB D+

12

13

FIG 4-3. USB D-

3-17

5. REMOTE CONTROL

14

FIG 5-1. Input Voltage

47K

15

16

FIG 5-2. Low Timing

4.7K

100R

14

15
16

EC301

100uF/16V

8050

C301

C304

100R

C302

FIG 5-3. High Timing

3-18

Item Measured Spec.

Input Level 3.3 V

IR Receiver Spec:

2.7 ~ 5.5 V

“ Low” Timing 4.4 ms 3.6 ms ~ 5.04 ms

“ High” Timing 4.48 ms 4.08 ms ~ 5.04 ms

6. OPTICAL

17

18

FIG 6-1. OPT_IN

FIG 6-2. OPT_DET

18

17

3-19

7. PORTABLE

XUY^G} 

19

20

FIG 7-1. ADC IC 5 V

20

19

21

21

FIG 7-2. ADC IC 3.3 V

X

FIG 7-3. Analog Input Voltage

3-20

8. AUDIO PWM(1/2)

22 23

FIG 8-1. PWM IC 3.3 V FIG 8-2. PWM IC 1.2 V

24

25

FIG 8-3. BCK

C456

22

C457

25

FB426
600RH

FB427

600RH

24

100R

100R

C454

100R

100R

C452

C453

100R

C444

23

C445

C446

C447

FIG 8-4. LRCK

3-21

AUDIO PWM(2/2)

26

FIG 8-5. Front L/R

27

-

384.14 kHz

3R3

C705

1K

1K

26

FB701
600RH

C707

C708

C709

68K

100R

C710

C711

384.17 kHz

FIG 8-6. Subwoofer

27

C712

100R

NC

2.2k

C714

FB702 600RH

C713

3-22

9. AUDIO AMP

28

29

30

31

FIG 9-1. AMP IC PVDD: 32 V

PVDD

GVDD

AMP_PDN

FIG 9-2.

C707

C709

100R

C711

FB701
600RH

C708

C710

18R

C715

C716

C717

C718

C701

C702

18R

C732

28

560R

560R

560R

560R

18R

C733

18R

29

330K

C1

C755

C756

C757

C2

C758

30

31

68K

3-23

C712

100R

NC

2.2k

C714

FB702 600RH

C713

3-24

3-263-25

CON1
AC IN

SMPS
PCB

MAIN
PCB

USB PCB

DISPLAY
PCB

KEY PCB

BT module

F/L SPK

F/R SPK

USBPORTOPT

subwoofer

AC IN

WIRING DIAGRAM

3-283-27

Amplifier

TAS5612L

POTABLE IN

Optical in

LED Display

ATA7819Y

LED Driver

SMI616

SMPS

25 W/ 6 Ohm

25 W/ 6 Ohm

SPDIF

R/L

PWM

Tact key

DSP

PS9860

IIS

ADC

PCM1808

Bluetooth

MB8811C1B

70 W/ 4 Ohm

+32 V

DC-DC

IR

USB Port

FLASH

32 M

SDRAM
4 x 16 M

CS8422

FLASH

1M

IIS

IIS

IIC

SPI

SPI

IIC

Main chip IC

MLC3730

BLOCK DIAGRAM

3-303-29

A

1

2

3

4

5

6

7

8

9

10

11

12

B C D E F G H I J K L M N O P Q R ST

CAUTION:

Danger if fuse is incorrectly replaced.

Replace only with the type identical to fuse rating

and(or) model name described in main label.

Warning
Parts that are shaded are critical with
respect to risk of fire or electrical shock.

CIRCUIT DIAGRAMS

1. SMPS CIRCUIT DIAGRAM

WHEN SERVICING THIS CHASSIS, UNDER NO
CIRCUMSTANCES SHOULD THE ORIGINAL
DESIGN BE MODIFIED OR ALTERED WITHOUT
PERMISSION FROM THE LG CORPORATION. ALL
COMPONENTS SHOULD BE REPLACED ONLY WITH
TYPES IDENTICAL TO THOSE IN THE ORIGINAL
CIRCUIT. SPECIAL COMPONENTS ARE SHADED

ON THE SCHEMATIC FOR EASY IDENTIFICATION.
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY
DIFFER FROM THE ACTUAL CIRCUIT USED. THIS
WAY, IMPLEMENTATION OF THE LATEST SAFETY
AND PERFORMANCE IMPROVEMENT CHANGES
INTO THE SET IS NOT DELAYED UNTIL THE NEW
SERVICE LITERATURE IS PRINTED.

1. Shaded( ) parts are critical for safety. Replace only
with specified part number.

2. Voltages are DC-measured with a digital voltmeter
during Play mode.

IMPORTANT SAFETY NOTE :

3-323-31

12

13

5

6

4

3

7 8
9 10

1

: WAVEFORM NUMBER

A

1

2

3

4

5

6

7

8

9

10

11

12

B C D E F G H I J K L M N O P Q R ST

EC102

100uF/16V

3904

R173

4.7K

R1B1

1K

R1B2

1K

C179

R172

NC

2. MAIN - DSP CIRCUIT DIAGRAM

3-343-33

3. MAIN - POWER CIRCUIT DIAGRAM

17

21

11

20

18

2

19

: WAVEFORM NUMBER

A

1

2

3

4

5

6

7

8

9

10

11

12

B C D E F G H I J K L M N O P Q R ST

3904

R435

10K

R436

1K

R437

1K

C471

100uF/16V

C472

R439
10K

R438

10K

R441

20K

EC405

100uF/16V

C475

3904

R463

1K

R464

1K

3904

R716

1K

R717

NC

R715
10K

R718

1K

EC705

100uF/16V

3-363-35

29

28

23

22

26

30

27

31

24

25

2

: WAVEFORM NUMBER

A

1

2

3

4

5

6

7

8

9

10

11

12

B C D E F G H I J K L M N O P Q R ST

FB701
600RH

100R

C707

C708

C709

68K

C710

C711

C712

100R

C714

FB702 600RH

C713

3R3

C705

1K

1K

C704

1K

C703

C706

10K

C715

C716

C717

C718

C728

C729

C721

3R3

C723

C724

560R

C727

C730

C726 C731

C755

CY1

NC

2.2k

560R

560R 560R

560R 560R

560R 560R

3R3

4.7K

4.7K

3R3

3R3

C722

C756

C757

C758

330K

CY2

CY3

CY4

CY5

CY6

CY7

CY8

CY9

C732

C733

18R

18R

C701

C702

18R

18R

L425

600RH

FB427

600RH

C457

C456

C440

C441

C444

100R

100R

100R

100R

4.7K

4.7K

4.7K

100R

C445

C446

C447

C448

33R

33R

33R

33R

C449

FB426
600RH

C453

C452

C454

100R

100R

100R

100R

100R

C1

C2

4. MAIN - PWM & AMP CIRCUIT DIAGRAM

3-383-37

16

15

14

: WAVEFORM NUMBER

A

1

2

3

4

5

6

7

8

9

10

11

12

B C D E F G H I J K L M N O P Q R ST

FRONT_BOARD

LED
IR

3.3V
SDA
SCL
GND

P_R
P_L
P_DET
P_GND
SPDIF
GND
5V
D+
D­GND

KEY

GND

STBY-->H

SW+
SW-

GND

KEY

KEY_BOARD

GND

5V

SW+

SW-

IR

GND

V+

REM

HM338-10B

R305

47K

R304

100R

1

SEG52SEG63SEG74GRID05GRID16GRID27GRID38GRID49SCL10SDA11GND12GRID513GRID614GRID7

15

GRID8

16

GRID9

17

GRID10

18

GRID11

19

GRID12

20

GRID13

21

GRID14

22

GRID15

23

SEGO

24

SEG1

25

VDD

26

SEG227SEG328SEG4

IC301

SM1616

LED2

RED LED

Q301

8050

R303

100R

R302

4.7K

EC301

100uF/16V

C301

100NF

C302

100PF

R301

10K

12

43

SW301

POWER

R306
100R

12

43

SW302

FUN

R307
680R

12

43

SW303

VOL-

R308

1K

12

43

SW304

VOL+

R309

1.5K

1

OUT

2

GND

3

VCC

JK502

4

2

3

1

1:VCC

2:D-

3:D+

4:GND

JK503

USB

L505

600RH

C506

100NF

L504

600RH

L503

600RH

L502

600RH

L501

600RH

L506

0R

L507

0R

L508

600RH

L509

1KRH

C508

NC

C507

10UF

C501

100PF

C502

100PF

C503

100PF

C505

10PF

TP6

1

2

3

D502
NC

1

2

3

D501

NC

1

2

3

D302

NC

1

2

3

D301

NC

R310

10K

R311

10K

R312

100R

R313

100R

EC302

100uF/16V

C305

100NF

1

GRID002GRID013GRID024GRID035SEG006GRID047GRID058SEG019GRID0610GRID0711SEG0212GRID0813GRID0914SEG0315SEG0416GRID1017GRID1118SEG0519SEG0620GRID1221GRID1322SEG0723GRID1424GRID15

LED301

LED_ATA7216AW-P12

1

SPK+

2

SPK-

JK301

C307

100NF

C308

100NF

R
L

123

4
5

6

7

8

9

JK504

1

2

3

4

5

6

7

8

9

10

CON502

1

2

3

4

L510

22UH

R501

0R

R502

0R

R503

0R

R504

0R

C310

10UF

C304

10UF

C306

10UF

C311

100NF

1

2

3

4

CON303

1

2

3

4

5

6

7

CON301

CN/7PIN

C313

100NF

C314

330PF

C315

330PF

R317

0R

R316

NC

1

2

3

4

5

CON302

1

2

3

D503

KDS226

C316

10NF

1

2

3

D300

KDS226

C312

103P

R318
100R

C317

100PF

C504
100R

IR

DISPLAY_3.3V

STB_LED

DISPLAY_3.3V

DISPLAY_SDA

DISPLAY_SCL

FGND

FGND

FGND

FGND FGND

FGND

DISPLAY_3.3V

DISPLAY

5V

FGND

FGND

DISPLAY_SCL

DISPLAY_SDA

FGND

STB_LED

IR

GRD00

SEG00

SEG01

SEG02

SEG03

SEG04SEG05

SEG06

SEG07

GRD00

GRD01

GRD02

GRD03

GRD04

GRD05

GRD06

GRD07 GRD08

GRD09

GRD10

GRD11

GRD12

GRD13

GRD14

GRD15

GRD01

GRD02

GRD03

GRD04

GRD05

GRD06

GRD07

GRD08

GRD09

GRD10

GRD11

GRD12

GRD13

GRD14

GRD15

SEG00

SEG01

SEG02

SEG03

SEG04

SEG05

SEG06

SEG07

FGND FGND

FGND

FGND

FGND

5V

FGND

FGND FGND

DISPLAY_SCL

DISPLAY_SDA

5. DISPLAY/ KEY/ USB CIRCUIT DIAGRAM

3-403-39

CIRCUIT VOLTAGE CHART

Designator Description Pin Voltage Spec Measured Voltage

IC101 Digital Signal

Processors

1, 43, 90, 132, 158 3.0~3.6 V 3.28 V

23, 55, 72, 107, 142, 160 1.1~1.3 V 1.19 V

57, 60, 164(USB_VCC) 3.0~3.6 V 3.28 V

66(USB_VCC) 1.1~1.3 V 1.19 V

68(OSC_VCC) 3.0~3.6 V 3.28 V

87(PLL_VCC) 1.1~1.3 V 1.19 V

IC102 SDRAM 1, 3, 9, 14, 27, 43, 49 3.0~3.6 V 3.28 V

IC105 FLASH 8 3.0~3.6 V 3.28 V

IC106 FLASH 8 3.0~3.6 V 3.28 V

IC400 ADC IC

3 4.75~5.25 V 4.98 V

4 3.0~3.6 V 3.28 V

IC401

Digital Audio

Function

19, 22 3.0~3.6 V 3.28 V

IC402 DC TO DC

1 31~33 V 32 V

2 3.0~3.6 V 3.28 V

IC404 DC TO DC

1 31~33 V 32 V

2 11~13 V 11.8 V

IC405 DSP IC

17, 34, 43, 52, 66 3.0~3.6 V 3.28 V

6, 25, 35, 63, 67 1.1~1.3 V 1.2 V

IC406 LDO IC

1 11~13 V 11.8 V

2 4.75~5.25 V 4.98 V

IC701 AMP IC

1, 2, 22 11~13 V 11.8 V

29, 30, 31, 36, 37, 38 31~33 V 32 V

3-423-41

PRINTED CIRCUIT BOARD DIAGRAMS

1. SMPS P. C. BOARD DIAGRAM

(TOP VIEW)

(BOTTOM VIEW)

NOTE) Warning

Parts that are critical with respect to risk
of fire or electrical shock.

3-443-43

2. MAIN P. C. BOARD DIAGRAM

(TOP VIEW)

(BOTTOM VIEW)

3-463-45

3. DISPLAY P. C. BOARD DIAGRAM

5. USB P. C. BOARD DIAGRAM

4. KEY P. C. BOARD DIAGRAM

(TOP VIEW)

(TOP VIEW)

(TOP VIEW)

(BOTTOM VIEW)

(BOTTOM VIEW)

(BOTTOM VIEW)

3-483-47