CONFIDENTIAL

SERVICE MANUAL
LG Wi-Fi Sound Bar
SERVICE MANUAL

MODEL: SK10Y (SK10Y, SPK8-W)

MODEL: SK10Y
(SK10Y, SPK8-W)

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

P/NO : AFN78212071 JANUARY, 2018

“Any reproduction, duplication, distribution (including by way of email, facsimile or other

electronic means), publication, modification, copying or transmission of this Service Manual is
STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics
entity from which you received this Service Manual. The material covered by this prohibition includes,
without limitation, any text, graphics or logos in this Service Manual.”

Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 CONTENTS

SECTION 1 ........ GENERAL

SECTION 2 ........ CABINET & MAIN CHASSIS
SECTION 3 ........ ELECTRICAL
SECTION 4 ........ WIRELESS SUBWOOFER PART
SECTION 5 ........ WIRELESS RECEIVER PART (OPTION)

1-1 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SECTION 1
SUMMARY

CONTENTS

PRODUCT SAFETY SERVICING GUIDELINES FOR AUDIO PRODUCTS .................................................... 1-3

SERVICING PRECAUTIONS ............................................................................................................................ 1-4

• GENERAL SERVICING PRECAUTIONS
• INSULATION CHECKING PRODEDURE
• ELECTROSTATICALLY SENSITIVE (ES) DEVICES

NAME OF EACH COMPONENT ....................................................................................................................... 1-5

WIRELESS SUBWOOFER CONNECTION....................................................................................................... 1-7

REAR SPEAKERS CONNECTION (SOLD SEPARATELY) ............................................................................ 1-8

WOOFER & REAR PAIRING METHOD............................................................................................................ 1-9

HIDDEN KEY MODE ....................................................................................................................................... 1-10

SOFTWARE UPDATE GUIDE......................................................................................................................... 1-11

SPECIFICATIONS ........................................................................................................................................... 1-14

1-2 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 PRODUCT SAFETY SERVICING GUIDELINES
FOR AUDIO PRODUCTS
IMPORTANT SAFETY NOTICE
This manual was prepared for use only by properly trained audio-video service
technicians.
When servicing this product, under no circumstances should the original design be
modified or altered without permission from LG Corporation. All components should
be replaced only with types identical to those in the original circuit and their physical
location, wiring and lead dress must conform to original layout upon completion of
repairs.
Special components are also used to prevent x-radiation, shock and fire hazard.
These components are indicated by the letter “x” included in their component des-
ignators and are required to maintain safe performance. No deviations are allowed
without prior approval by LG Corporation.
Circuit diagrams may occasionally differ from the actual circuit used. This way, imple-
mentation of the latest safety and performance improvement changes into the set is
not delayed until the new service literature is printed.
TIPS ON PROPER INSTALLATION
CAUTION : Do not attempt to modify this product in any way. Never perform cus-
1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelf
tomized installations without manufacturer’s approval. Unauthorized modifications
space over, or close to, a heat duct, or in the path of heated air flow.
will not only void the warranty, but may lead to property damage or user injury.
2. Avoid conditions of high humidity such as: outdoor patio installations where dew
Service work should be performed only after you are thoroughly familiar with these
is a factor, near steam radiators where steam leakage is a factor, etc.
safety checks and servicing guidelines.
3. Avoid placement where draperies may obstruct venting. The customer should
GRAPHIC SYMBOLS also avoid the use of decorative scarves or other coverings that might obstruct
The exclamation point within an equilateral triangle is intended to alert ventilation.
the service personnel to important safety information in the service
literature. 4. Wall- and shelf-mounted installations using a commercial mounting kit must follow
The lightning flash with arrowhead symbol within an equilateral the factory-approved mounting instructions. A product mounted to a shelf or plat-
triangle is intended to alert the service personnel to the presence of form must retain its original feet (or the equivalent thickness in spacers) to provide
noninsulated “dangerous voltage” that may be of sufficient magnitude adequate air flow across the bottom. Bolts or screws used for fasteners must not
to constitute a risk of electric shock. touch any parts or wiring. Perform leakage tests on customized installations.
The pictorial representation of a fuse and its rating within an equilat- 5. Caution customers against mounting a product on a sloping shelf or in a tilted
eral triangle is intended to convey to the service personnel the follow- position, unless the receiver is properly secured.
ing fuse replacement caution notice: 6. A product on a roll-about cart should be stable in its mounting to the cart.
CAUTION : FOR CONTINUED PROTECTION AGAINST RISK Caution the customer on the hazards of trying to roll a cart with small casters
OF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND across thresholds or deep pile carpets.
RATING AS MARKED NEAR EACH FUSE.
7. Caution customers against using extension cords. Explain that a forest of exten-
SERVICE INFORMATION sions, sprouting from a single outlet, can lead to disastrous consequences to
While servicing, use an isolation transformer for protection from AC line shock. After home and family.
the original service problem has been corrected, make a check of the following:
FIRE AND SHOCK HAZARD
1. Be sure that all components are positioned to avoid a possibility of adjacent com-
ponent shorts. This is especially important on items trans-ported to and from the
repair shop.
2. Verify that all protective devices such as insulators, barriers, covers, shields, strain
reliefs, power supply cords, and other hardware have been reinstalled per the
original design. Be sure that the safety purpose of the polarized line plug has not
been defeated.
3. Soldering must be inspected to discover possible cold solder joints, solder
splashes, or sharp solder points. Be certain to remove all loose foreign particles.
4. Check for physical evidence of damage or deterioration to parts and components,
for frayed leads or damaged insulation (including the AC cord), and replace if
necessary.
5. No lead or component should touch a high current device or a resistor rated at 1
watt or more. Lead tension around protruding metal surfaces must be avoided.
6. After reassembly of the set, always perform an AC leakage test on all exposed
metallic parts of the cabinet (the channel selector knobs, antenna terminals,
handle and screws) to be sure that set is safe to operate without danger of electri-
cal shock. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS
TEST. Use an AC voltmeter having 5000 ohms per volt or more sensitivity in the
following manner: Connect a 1500 ohm, 10 watt resistor, paralleled by a .15 mfd
150V AC type capacitor between a known good earth ground water pipe, con-
duit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage
across the combination of 1500 ohm resistor and .15 mfd capacitor. Reverse the
AC plug by using a non-polarized adaptor and repeat AC voltage measurements
for each exposed metallic part. Voltage measured must not exceed 0.75 volts
RMS. This corresponds to 0.5 milliamp AC. Any value exceeding this limit consti-
tutes a potential shock hazard and must be corrected immediately.

1-3 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SERVICING PRECAUTIONS
CAUTION: Before servicing the Audio products covered by this Electrostatically Sensitive (ES) Devices
service data and its supplements and addends, read and fol- Some semiconductor (solid state) devices can be damaged
low the SAFETY PRECAUTIONS. easily by static electricity. Such components commonly are
NOTE: if unforeseen circumstances create conflict between called Electrostatically Sensitive (ES) Devices. Examples
the following servicing precautions and any of the safety of typical ES devices are integrated circuits and some field
precautions in this publication, always follow the safety pre- effect transistors and semiconductor chip components.
cautions. The following techniques should be used to help reduce the
Remember Safety First : incidence of component damage caused by static electricity.
General Servicing Precautions
1. Always unplug the Audio products AC power cord from the 1. Immediately before handling any semiconductor compo-
AC power source before: nent or semiconductor-equipped assembly, drain off any
(1) Removing or reinstalling any component, circuit board, electrostatic charge on your body by touching a known
module, or any other assembly. earth ground. Alternatively, obtain and wear a commer-
(2) Disconnecting or reconnecting any internal electrical cially available discharging wrist strap device, which should
plug or other electrical connection. be removed for potential shock reasons prior to applying
(3) Connecting a test substitute in parallel with an electro- power to the unit under test.
lytic capacitor.
Caution: A wrong part substitution or incorrect polarity 2. After removing an electrical assembly equipped with ES
installation of electrolytic capacitors may result in an devices, place the assembly on a conductive surface such
explosion hazard. as aluminum foil, to prevent electrostatic charge buildup or
exposure of the assembly.
2. Do not spray chemicals on or near this Audio products or any
of its assemblies. 3. Use only a grounded-tip soldering iron to solder or unsolder
ES devices.
3. Unless specified otherwise in this service data, clean elec-
trical contacts by applying an appropriate contact cleaning 4. Use only an anti-static solder removal device. Some solder
solution to the contacts with a pipe cleaner, cotton-tipped removal devices not classified as “anti-static” can generate
swab, or comparable soft applicator. electrical charges sufficient to damage ES devices.
Unless specified otherwise in this service data, lubrication
of contacts is not required. 5. Do not use freon-propelled chemicals. These can generate
an electrical charge sufficient to damage ES devices.
4. Do not defeat any plug/socket B+ voltage interlocks with
which instruments covered by this service manual might be 6. Do not remove a replacement ES device from its protective
equipped. package until immediately before you are ready to install
it. (Most replacement ES devices are packaged with leads
5. Do not apply AC power to this Audio products and / or any electrically shorted together by conductive foam, aluminum
of its electrical assemblies unless all solid state device heat foil, or comparable conductive material).
sinks are correctly installed.
7. Immediately before removing the protective material from
6. Always connect the test instrument ground lead to an the leads of a replacement ES device, touch the protective
appropriate ground before connecting the test instrument material to the chassis or circuit assembly into which the
positive lead. Always remove the test instrument ground device will be installed.
lead last.
Caution: Be sure no power is applied to the chassis or cir-
Insulation Checking Procedure cuit, and observe all other safety precautions.
Disconnect the attachment plug from the AC outlet and turn
the power on. Connect an insulation resistance meter (500V) 8. Minimize bodily motions when handling unpackaged
to the blades of the attachment plug. The insulation resis- replacement ES devices. (Normally harmless motion such
tance between each blade of the attachment plug and acces- as the brushing together of your clothes fabric or the lifting
sible conductive parts (Note 1) should be more than 1Mohm. of your foot from a carpeted floor can generate static elec-
Note 1: Accessible Conductive Parts include Metal panels, tricity sufficient to damage an ES device.)
Input terminals, Earphone jacks,etc.

1-4 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 NAME OF EACH COMPONENT
• Front Panel
Front panel

A 1 (Standby) > Caution

^|nyhmjxymjzsnyZYtwZQQ/ Precautions in using the touch buttons
F "Qzshynts- Precautions in using the touch buttons
y `xjymjytzhmgzyytsx|nymhqjfsfsiiw~
^jqjhyxymjkzshyntsfsinsuzyxtzwhj/"bTQT0 • Use
hands.the touch buttons with clean and dry
Selects the function and input source. (WI-FI,
Z[_&SOXTL]N0M_0WR_a0HDMI
OPT/HDMI ARC, BT, LG TV, HDMIIN1,IN1,HDMI
HDMIIN2,
IN2, hands.
PORTABLE)
PORTABLE) --InTsfmzrnijs{nwtsrjsy0|nujtzyfs~
a humid environment, wipe out any
rtnxyzwjtsymjytzhmgzyytsxgjktwj
moisture on the touch buttons before
p/o"atqzrj- zxnsl/
using.
 "bnQn- Otstyuwjxxymjytzhmgzyytsxmfwiytrfpj
y• Do not press the touch buttons hard to make
^jqjhyxbnQnkzshynts/
Selects Wi-Fi function. ny|twp/
it work.
B WPOnsinhfytw --If Tk~tzfuuq~yttrzhmxywjslym0nyhfs
you apply too much strength, it can
^mt|xhtssjhyntsxyfyzx/ damage the sensor of the touch buttons.
ifrfljymjxjsxtwtkymjytzhmgzyytsx/
y bmnyj"Mqnspnsl-5bfnynslktwsjy|twphtssjhynts
White (Blinking): Waiting for network connection •y Touch the button that you want to work in
_tzhmymjgzyytsymfy~tz|fsyyt|twpns
tsbnQnkzshynts
on Wi-Fi function order to operate the function correctly.
twijwyttujwfyjymjkzshyntshtwwjhyq~/
y bmnyj"^yf~nslts-5Yjy|twphtssjhyntsnx
White (Staying on): Network connection is • Be careful not to have any conductive material
y Mjhfwjkzqstyytmf{jfs~htsizhyn{jrfyjwnfq
htruqjyjitsbnQnkzshyntstwymjtymjw
completed on Wi-Fi function or the other such as metallic object on the touch buttons.
xzhmfxrjyfqqnhtgojhytsymjytzhmgzyytsx/
kzshyntsxfwjxjqjhyji/
functions are selected. It can cause malfunctions.
Tyhfshfzxjrfqkzshyntsx/
y bmnyj"Onrrji-5^yfsig~rtij|nymsjy|twp
htssjhynts/
, Note
y ]ji"^yf~nslts-5^yfsig~rtij|nymtzysjy|twp ]jrt{jktwjnlsrfyjwnfqxgjy|jjsymjlwnqqfsi
Remove foreign materials between the grill and
htssjhynts/ ymjhfxjg~zxnslfhtyytsx|fg/
the case by using a cotton swab.
C ]jrtyjxjsxtw
D Onxuqf~|nsit|

1-5 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
• Rear Panel
Rear panel

A USB (Service only) D OPTICAL IN connector

^&bit|sqtfihtssjhytw Ntssjhyytfstuynhfqij{nhj/
Connect to an optical device.
B LAN port E HDMI OUT (TV ARC)
Ntssjhyytfwtzyjw/
Connect to a router. NtssjhyytSOXTTY"L]N-ts_a/
C PORTABLE IN connector F HDMI
HDMI IN
IN (1)
(1)//HDMI
HDMIIN IN(2)
(2)
Ntssjhyutwyfgqjij{nhj/
Connect portable device. Ntssjhyytij{nhj|nymSOXTZ`_/
Connect to device with HDMI OUT.

1-6 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WIRELESS SUBWOOFER CONNECTION
LED indicator of wireless subwoofer Note:
• It takes a few seconds (and may take longer) for the
LED Color Status main unit and the subwoofer to communicate with
each other and make sounds.
Green
The connection is trying. • The closer the main unit and the subwoofer, the
(Blink)
better sound quality. It is recommended to install the
Green The connection is completed. main unit and the subwoofer as close as possible
The wireless subwoofer and avoid the cases below.
Red is in standby mode - There is a obstacle between the main unit and the
or the connection is failed. subwoofer.
Off The power cord of wireless - There is a device using same frequency with this
(No display) subwoofer is disconnected. wireless connection such as a medical equipment,
a microwave or a wireless LAN device.
- Keep the sound bar and the subwoofer away from
Setting up the wireless subwoofer the device (ex. wireless router, microwave oven,
etc.) over 1m (3.3 ft) to prevent wireless
for the first time
interference.
1. Connect the power cord of the sound bar and the
wireless subwoofer to the outlet.
2. Turn on the sound bar. The sound bar and the
wireless subwoofer will be automatically connected.
XG”GG
OZUZG›P

Manually pairing wireless subwoofer

When your connection is not completed, you can

check red LED on the wireless subwoofer and the
wireless subwoofer does not make sound. To solve
the problem, follow the steps below.

1. Press Pairing button on the rear of the wireless

subwoofer.

Pairing

- The green LED on the rear of the wireless

subwoofer blinks quickly. (If the green LED does
not blink, press and hold the Pairing button.)

2. Turn on the sound bar.

3. Pairing is completed.
- The green LED on the rear of the wireless
subwoofer turns on.

1-7 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 REAR SPEAKERS CONNECTION (SOLD SEPARATELY)
Connecting the rear speakers LED indicator of wireless receiver

1. Connect the black stripe wire to the terminal LED Color Status
marked - (minus) and the other end to the terminal
Yellow - green
marked + (plus). The connection is trying.
(Blink)
The wireless receiver is receiving
Yellow - green
the signal from the sound bar.
The wreless receiver is in
Red
standby mode.
Off The power cord of wireless
(No display) receiver is disconnected

Setting up the wireless receiver for the

first time
1. Connect the power cord to the wireless receiver
to the outlet.
2. Turn on the main unit : The sound bar and
wireless receiver will be automatically connected.
- Yellow - green LED on the wireless receiver
turns on.

Manually pairing wireless receiver

When your connection is not completed, you can

see the red LED on the wireless receiver and rear
speakers are not made sound. To solve the problem,
follow the below steps.

1. Press PAIRING button on the rear of the wireless

2. Connect the wireless receiver and the rear receiver.
speakers (right, left) with the speaker cables.

Color Position
Grey Rear right
Blue Rear left

Note :
You need to purchase the wireless rear speakers kit
(SPK8-S) to enjoy surround sound.
- The yellow - green LED on the wireless receiver
Caution : blinks quickly.
• Use the speaker supplied with this unit only. Using
any other speaker may cause malfunction. 2. Turn on the main unit
• Be sure to match the speaker cable to the 3. Paring is completed.
appropriate terminal on the components: + to + and - The yellow - green LED on the wireless receiver
– to –. If the cables are reversed, the sound will be turns on.
distorted and will lack bass.

1-8 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WOOFER & REAR PAIRING METHOD
How to pair Subwoofer and Rear kit

1) Down volume minimum to use Remocon or MAIN set key (Press ‘-’ key).
2) Press ‘Mute’ key (about 2~3 seconds) on Remocon and then will display “WL RESET” on LCD.
3) Press paring key on the Subwoofer and Rear kit.
4) When woofer and rear kit attempt to connect wireless, the Green color LED blink faster than standby status.
5) When woofer and rear kit connect wireless completely, the LED will maintain Green color.

Paring Key

Standby LED

Mute Key

< Remocon > < Subwoofer > < Rear kit back > < Rear kit front >

1-9 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 HIDDEN KEY MODE
1. FACTORY RESET
• Key : Press WiFi Button on the soundbar for 5 seconds.
• Result : Initialize EEPROM (MICOM) and MPEG (MAIN).
(But Wireless Woofer and Wireless Rear speakers are not)

2. SW Version Display
• Enter : Press Volume ‘-’ on Soundbar with ‘Play/Pause’ on Remocon for 5 seconds.
• Change Display : Whenever press ‘F.SKIP’ on remocon, displaying SW program is changed.
M: MICOM
PQ : PEQ
B: MAIN
D: DSP
H: HDMI
TX : WOOFER TX
RX : WOOFER RX
RT : REAR TX
RR : REAR RX
MQ : MEQ
T: TOUCH
• Result : Scroll SW Version on Soundbar VFD.
• EXIT : Press ‘Play/Pause’ on Remocon for 5 seconds.

< MICOM > < PEQ > < MAIN > < DSP >

3. OPTION Edit
• Enter : Volume ‘-’ on soundbar with ‘AV SYNC’ key on remocon for 5 seconds.
• Result : VFD display OPTION number and OPTION data like ‘’00 00” “02 4A” …
• How to Change Option data :
Change Option data by press ‘PLAY/PAUSE’ on remocon key,
change option number by press ‘B.SKIP’ on remocon, ‘F.SKIP’ on remocon after change option finish,
press ‘AUTO VOL’ key. System will save option and restart.

4. WIRELESS WOOFER & REAR SPEAKER TX RESET

• ENTER : Press Mute key for 3 seconds when Woofer and Wireless Rear speaker is off.
• RESULT : VFD displays ‘WL RESET’’ and initialize TX module.
Paring will be disconnected.

< MAIN Key > < Remocon >

1-10 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SOFTWARE UPDATE GUIDE
1. Using USB
1-1. USB UPDATE FILE NAME (yymmrrrr is 8 digit version number)
MAIN  MAIN_SK10_yymmrrrr.BIN
MICOM  MICOM_SK10_yymmrrrr.HEX
DSP  DSP_SK10_yymmrrrr.BIN
HDMI  HDMI_SK10_yymmrrrr.BIN
PEQ  PEQ_SK10_yymmrrrr.BIN
TOUCH  TOUCH_SK10.DLD
WOOFERRx  WOOFERRX_SK10_yymmrrrr.BIN
WOOFERTx  WOOFERTX_SK10_yymmrrrr.BIN
REARRx  REARRX_SK10_yymmrrrr.BIN
REARTx  REARTX_SK10_yymmrrrr.BIN

1-2. HOW TO UPDATE

• Copy Update file to USB Root Directory.
• Turn on soundbar and change function to ‘WIFI’.
• Insert USB to USB Port at the back side of soundbar.
• VFD display ‘UPGRADE’
• Play/Pause key on remocon or WIFI key on soundbar can start UPDATE.

   

• After Update finish, system will restart automatically.

• If reboot is finish, VFD display ‘WiF’i.
DO NOT turn off during displaying ‘PLEASE WAIT’ on VFD.

※ Before update Woofer RX or Rear Rx WOOFER RX, Woofer and Rear Speaker have to be paired
with Main soundbar

1-11 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2. Using APP
Before Network update, soundbar has to be connected with ‘LG Wifi Soundbar’ Application.

Step 1. Select setting gui.

Step 2. Select software version display.

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Using APP

Step 3. System compare current version

with the latest version at server. Step 5. Update file downloading.
Step 4. If there is new version on server, press Update.

Step 7. After update finish, application

Step 6. Updating
show the result.

1-13 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SPECIFICATIONS
• GENERAL
Power consumption Refer to the main label on the unit.
Power consumption Refer to the main label on the unit.
Dimensions (W x H x D) Approx. 1443.0 mm x 63.0 mm x 146.0 mm (with foot)
(56.8 inch x 2.5 inch x 5.7 inch)
Operating temperature 5 °C to 35 °C (41 °F to 95 °F)
Operating humidity 5 % to 90 %
Available Digital Audio In Sampling Frequency 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
Available Digital Audio In format Dolby Atmos, Dolby Audio, DTS Digital Surround, PCM

• INPUT/OUTPUT
OPTICAL IN 3 V (p-p), Optical jack x 1
PORTABLE IN 0.32 Vrms (3.5 mm stereo jack) x 1
HDMI IN (1) / HDMI IN (2) 19 Pin (Type A, HDMI™ connector) x 2
HDMI OUT 19 Pin (Type A, HDMI™ connector) x 1
4K Sources dependent on HDCP 2.2 are supported at 4K resolutions.

• AMPLIFIER (RMS Output)

Total 550 W RMS
Front 50 W RMS x 2 (4 Ω at 1 kHz, THD 10 %)
Center 50 W RMS (4 Ω at 1 kHz, THD 10 %)
Surround 50 W RMS x 2 (4 Ω at 1 kHz, THD 10 %)
Top 50 W RMS x 2 (4 Ω at 1 kHz, THD 10 %)
Subwoofer 200 W RMS (3 Ω at 80 Hz, THD 10 %)

• WIRELESS SUBWOOFER
Power requirements Refer to the main label on the subwoofer.
Power consumption Refer to the main label on the subwoofer.
Type 1 Way 1 Speaker
Impedance 3Ω
Rated Input Power 200 W RMS
Max. Input Power 400 W RMS
Dimensions (W x H x D) Approx. 221.0 mm x 390.0 mm x 312.8 mm
(8.7 inch x 15.4 inch x 12.3 inch)
• SYSTEM
LAN port Ethernet jack x 1, 10 BASE-T/100 BASE-TX
Wireless LAN (Internal antenna) 802.11a/b/g/n Wi-Fi networks

SPK8-S (SPK8-S, S78S1-S), Sold Separately

• WIRELESS RECEIVER
Power requirements Refer to the main label on the wireless receiver.
Power consumption Refer to the main label on the wireless receiver.
Rear 70 W RMS x 2 (3 Ω at 1 kHz, THD 10 %)
Dimensions (W x H x D) Approx. 60.0 mm x 220.0 mm x 175.0 mm
(2.4 inch x 8.7 inch x 6.9 inch)

• REAR SPEAKERS (Each)

Type 1 Way 1 Speaker
Impedance 3Ω
Rated Input Power 70 W RMS
Max. Input Power 140 W RMS
Dimensions (W x H x D) Approx. 100.0 mm x 140.0 mm x 100.0 mm
(3.9 inch x 5.5 inch x 3.9 inch)

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

1-14 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SECTION 2
CABINET & MAIN CHASSIS

CONTENTS

DISASSEMBLY INSTRUCTIONS ..................................................................................................................... 2-2

1. HOW TO DISASSEMBLE THE MAIN UNIT ............................................................................................. 2-2
2. HOW TO DISASSEMBLE THE SUBWOOFER ........................................................................................ 2-6
3. HOW TO INSTALLATION THE TV STAND .............................................................................................. 2-8
EXPLODED VIEWS ......................................................................................................................................... 2-9
1. MAIN UNIT SECTION ............................................................................................................................. 2-9
2. WIRELESS SUBWOOFER SECTION .................................................................................................... 2-11
3. PACKING ACCESSORY SECTION ....................................................................................................... 2-13

2-1 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 DISASSEMBLY INSTRUCTIONS
1. HOW TO DISASSEMBLE THE MAIN UNIT
1-1. Disassemble Main set

2-2 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
HOW TO DISASSEMBLE THE MAIN UNIT
Disassemble Main set

2-3 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
HOW TO DISASSEMBLE THE MAIN UNIT
Disassemble Main set

1) Remove the 33 Screws (1SSZR-0097X) in the direction of the figure.

2) Remove the 3 Connectors.

3) Remove the 4 Screws (1SSZR-0097X) in the direction of the fi gure.

2-4 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
HOW TO DISASSEMBLE THE MAIN UNIT
Disassemble Main set

4) Remove the 2 Dampers.

5) Remove the 6 Screws (1SSZR-0097X) in the direction of the figure.

2-5 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2. HOW TO DISASSEMBLE THE SUBWOOFER
2-1. Rear Panel Assembly
1) Remove the 11 screws.

Figure 2-1 (1)

2) Remove the Cable.

Figure 2-1 (2)

2-6 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
HOW TO DISASSEMBLE THE SUBWOOFER
2-3. AMP+SMPS PCB Assembly
1) Remove the 7 Screws.

Figure 2-3 (1)

2) Remove the 2 Cables.

Figure 2-3 (2)

2-7 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 INSTALLATION THE TV STAND
3. HOW TO INSTALLATION THE TV STAND

• After arranging the cables, install the sound bar.

Installation (SK95/SK90) Installation (C8/B8)

2-8 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
EXPLODED VIEWS
1. MAIN UNIT 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.

M
N
A81R

A42
CABLE5
A80 M
A44A
G
A48
B A
HDMI+JACK
P
CABLE2 G
N CABLE4 J
MAIN E
A52 F
J E
BT B O

267 WIRELESS D
C D
CABLE3 A46
A54 263
262 A43 A
I
C SMPS
264

I R CABLE6
A54 K

O CABLE1 FRONT A47 L

CABLE8 Q WIRELESS
K
LCD01 268 A80C
A81L
P
A55
H
A44

CABLE7
L
A80

A41 H

261
A51 Wi-Fi 300

2-9 2-10 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2. WIRELESS SUBWOOFER 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.

A900

A900W 951

B B 952

A45W

A54W
953
A

961

954

956

ZWW~

958

2-11 2-12 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
3. PACKING ACCESSORY SECTION

835 Wall bracket 806 Optical cable

829 Cable tie 836 Screws (2)

900 Remote control 300 Power cord

2-13 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2-14 Copyright © 2018 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
 SECTION 3
ELECTRICAL

CONTENTS

WIRING DIAGRAM ............................................................................................................................................ 3-2

BLOCK DIAGRAMS .......................................................................................................................................... 3-3

1. SYSTEM BLOCK DIAGRAM .................................................................................................................. 3-3
2. POWER BLOCK DIAGRAM ................................................................................................................... 3-4
3. AUDIO SIGNAL FLOW ........................................................................................................................... 3-5

ONE POINT REPAIR GUIDE ............................................................................................................................ 3-6

1. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR “HELLO”
ON FRONT PANEL ................................................................................................................................. 3-6
2. NO SOUND ............................................................................................................................................. 3-9
3. PROTECTION ERROR......................................................................................................................... 3-13

WAVEFORMS OF MAJOR CHECK POINT.................................................................................................... 3-16

1. CRYSTAL .............................................................................................................................................. 3-16
2. FLASH ................................................................................................................................................... 3-17
3. REMOTE CONTROL ............................................................................................................................ 3-18
4. OPTICAL ............................................................................................................................................... 3-19

CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-21

1. ICs ......................................................................................................................................................... 3-21
2. CAPACITORS ....................................................................................................................................... 3-22
3. CONNECTORS ..................................................................................................................................... 3-22

PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-23

1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-23
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-25
3. JACK P. C. BOARD DIAGRAM ............................................................................................................ 3-29
4. FRONT P. C. BOARD DIAGRAM ......................................................................................................... 3-31
5. TOUCH KEY P. C. BOARD DIAGRAM ................................................................................................ 3-31

3-1 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 TOP View

8P, 2mm 2P, 2mm 6P, 2mm

26P, 0.5mm D
ST. SMD ST.
S SMD ST. SMD
Angle, SMD
Rear

Wireless

8P, 2mm
12P, 0.5mm HDMI 2in 1out Pot MAIN PCB ST, Lock, SMPS PCB
OPT
OP
able

LA N
angle. SMD SMD

8P, 1mm 8P, 1.25mm

HDMI PCB ST. SMD ST, Lock, SMD

12P, 2mm
12P
AG, HEADER, SMD
BT WIFI
Touch PCB
Front PCB 8P, 1mm

3-2
12P, 2mm angle, Lock. SMD
10P, 1mm ST, SOCKET, SMD
AG, Lock, SMD
(EAG62611102)
LCD Module
WIRING DIAGRAM

Bottom View Rear

Main PCB

Wire
less

Rear FFC

BT

Front PCB

Only for training and service purposes.

Copyright © 2018 LG Electronics Inc. All rights reserved.
LCD Module
 27M 25M 24.576M AMP (5.1.2)
SK10Y/SK10 only
TMDS/HPD/DDC 12.288M
192K/24bit
HDMI IN SPDIF
TMDS/HPD/DDC
Oscillator FL
OP AMP AMP
HDMI IN HDMI DRV603 TPA3118 TL
I2S 40M
Sil9777
TMDS/HPD/DDC/CEC
HDMI OUT 1.0/3.3V OP AMP AMP FR
BCK/LRCK DAC DRV603 TPA3118 TR
H_D0 DSP 8Ch
SPI D_D0~D3
MCLK/BCK/LRCK ADSP21584 ES9006A
S.Flash Rear OP AMP AMP SL
D0 19x19mm 3.3V/1.2V
1MB DRV603 TPA3118
MCLK/BCK/LRCK
SR
0.8p,349 BGA

74AHC244
24.576M MCLK/BCK/LRCK
D_D0 OP AMP AMP C
ARC+/- 1.1/1.5/3.3V DRV603 TPA3118
1. SYSTEM BLOCK DIAGRAM

DIR D_D3
CS8422 TX Wireless Woofer
SPDIF 3.3V SPI0 SPI
S.Flash

3-3
1MB
M_D0 16 SPI2
MCLK/BCK/LRCK
27M Rear
ADC DDR3 S.Flash TX Rear
PORTABLE
PCM1808 ADC_D0 128MB 16MB
MCIN SPI
S.Flash
OPTICAL IN OPTICAL 1MB SK10Y/SK9Y only
BLOCK DIAGRAMS

BT_RESET/WAKE UP
BT SPI/ BL_CTL
(CSR8510) USB+/-
SOC UART RMC/ LED FRONT PCB LCD
MT8506 M_RESET MICOM SMPS
D+/D- IR -Receiver 2 Color LED
WI-FI 1.2/1.5/3.3V 3.3VA/100p PVDD (20VA)
Ethernet I2C KEY
HDMI Key PCB(5 Key)
D+/D- DAC/DIR SK9Y/SK9 only
USB
(SVC only)
IRQ/SCL/SDA
32 8
Touch Key PCB(5 Key)
SPI
DDR3 NAND Touch IC
128MB
DDR3 512MB S.Flash Buzzer SK10Y/SK10 only
128MB 1MB

Only for training and service purposes.

Copyright © 2018 LG Electronics Inc. All rights reserved.
 AMP IC
25VA
TAS3118 x 4

3.3VA MICOM

SMPS 3.3VA Serial Flash

TLV62565
3.3VA
5.1 VA
12 VA MP9453 D_3.3V MPEG
→ DSP_1.1V
DCDC 1.2V MT8506
12VA→ D_1.2V
D_1.5V
For MPEG TLV62565
MP9442(2A/37V)
5.1 VA D_1.5V DDR3 X 1 (1GBit)
25VA→ 12VA → D_1.5V
MP9453 SY6288C
DCDC D_3.3V D_3.3V NAND FLASH
12 VA→ 5.1VA SW
DSP_1.1V
TLV62565 DSP
5.1 VA DSP_1.5V
2. POWER BLOCK DIAGRAM

SY6288C ADSP21584
→ 3.3VA DSP_3.3V
DSP_3.3V
TJ4310- LDO SW
DDR3
DSP_1.5V
5.1 VA Nanya1G
→ DAC_3.3V TLV62565
5.1 VA
Serial Flash
→ DSP_1.5V DSP_3.3V

3-4
Winbond128Mbit
LR1148G- LDO
DAC_3.3V Line Driver
→ DAC_1.2V DAC_3.3V
DRV603 x 3

DAC_3.3V DAC
DAC_1.2V ES9006

Buzzer SW HDMI_5.1VA
VCC_5V TPS2069
SW HDMI 4K
TPS2069 HD_1.0V SIL9777
HD_3.3V
USB
VCC_5V
JACK TLV62565 ADC PCM1808
SY6288C SY6288C D_3.3V
Rear_3.3V WL_3.3V 5.1 VA MP9453 DCDC
SW SW → 3.5V 5.1VA→HD_1.0V D_3.3V DIR CS8422

3.3VA OPTICAL

BT Module Remocon SY6288C PORTABLE

Touch Rear Wireless WIFI Module
LCD HD_3.3V
Module HDMI IN x 2
SW JACK PCB
FRONT PCB HDMI OUT x 1

Only for training and service purposes.

Copyright © 2018 LG Electronics Inc. All rights reserved.
 Audio output : Total 550 W
- Main : 350 W 0.1ch SK10Y/SK9Y only 0.2ch
- Subwoofer
: : 200 W, Rear : 140 W 柦勢
Wireless Rear
Wireless Rear
BT(CS8510) Module Wireless
Woofer 70Wx2
Module
USB_DP/DN 200W

NC_WF
USB_DP/DN

BCK
LRCK
BCK
LRCK
DSP_I2S
TP_TX/RX
Ethernet MPEG
3. AUDIO SIGNAL FLOW

MT8506

BCK
BCK
Potable in

LRCK

MCK
LRCK
A_DATA0 5.0.2ch
LPF
ADC
FR(7)

Rear L_R
SR 50W
OPT_SPDIF OPamp AMP
TR(3) DRV603 TPA3118
FR_FL(3)
TR 50W

3-5
LRCK

MCK
BCK
C(4)

LRCK

MCK
BCK
TR_C(1) FR 50W
OPamp AMP
MPEG_I2S DRV603 TPA3118
M_I2S_DATA0

LRCK
BCK
Demo_SPDIF DAC
ES9006 NC(5)
Optical In DSP
OPT_SPDIF
C 50W
ADSP NC_WF(2) OPamp AMP
DIR_I2S
21584 NC(2) DRV603 TPA3118
/ DATA0 FL 50W
HDMI_ARC DIR D_I2S
TL_NC(0)
Switching / DATA0
74AHC244 TL(1)
HDMI OUT TL 50W
OPamp AMP
HDMI_I2S / DATA0 DRV603
FL(8) TPA3118
SL 50W
HDMI IN_1 D_I2S_DATA1/2/3
HDMI
HDMI_SPDIF
HDMI IN_2

Only for training and service purposes.

Copyright © 2018 LG Electronics Inc. All rights reserved.
 ONE POINT REPAIR GUIDE
1. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR
“HELLO” ON FRONT PANEL
When you turn on your set, no message on the front panel, and stand-by LED doesn’t work.

1-1. IC300 System 12 VA (No 12 VA)

1-1-1. Solution
Replace MAIN board.

1-1-2. How to troubleshoot (Countermeasure)

1) Please check 20 VA of IC300 pin2 (VIN).
2) If 20 VA is abnormal, please check SMPS board (pin4, 5, 6).
3) If 20 VA is OK, but 12 VA is abnormal pin3 of IC300 (VOUT), replace MAIN board.

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

L301


IC300

< MAIN board top view >

3-6 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR
“HELLO” ON FRONT PANEL
When you turn on your set, it will blank / no message on front panel, and stand-by LED doesn’t work.

1-2. IC303 System 3.3 V (No 3.3 VA)

1-2-1. Solution
Replace MAIN/ FRONT board.

1-2-2. How to troubleshoot (Countermeasure)

1) Please check 3.3 VA of IC303 pin3.
2) If 3.3 VA is abnormal, replace MAIN board.
3) If 5.1 VA is OK, replace FRONT board.

1-2-3. Service hint (Any picture / Remark)

IC303



L304

< MAIN board top view >

3-7 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR
“HELLO” ON FRONT PANEL
When you turn on your set, it will blank / no message on front panel, and stand-by LED doesn’t work.

1-3. LCD System power 12 V, VCC_5V (No 12 V, VCC_5V)

1-3-1. Solution
Replace MAIN board.

1-3-2. How to troubleshoot (Countermeasure)

1) Please check CN101 12 V (pin7), VCC_5V (pin3).
2) If 12V, VCC_5V is abnormal, replace MAIN board.
3) If 12V, VCC_5V OK, replace FRONT board.

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

 


CN101

< MAIN board top view >

3-8 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
2. NO SOUND

2-1. BLUETOOTH
2-1-1. Solution
Replace Bluetooth module/ MAIN board.

2-1-2. How to troubleshoot (Countermeasure)

1) Please check status of Bluetooth cable connection (at CN102 and BT Module).
2) Please check 3.3 VA (at pin1 of CN102).
- If 3.3 VA is OK, please check BT_RST, USB_DP_BT, USB_DN_BT, BT_WAKEUP, BT_STANDBY
(pin10, 6, 7, 11, 12)
- If no signal, please replace MAIN board.

2-1-3. Service hint (Any picture / Remark)

CN102

< MAIN board top view >

3-9 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
NO SOUND

2-2. OPTICAL
2-2-1. Solution
Replace JACK board.

2-2-2. How to troubleshoot (Countermeasure)

1) Please check 3.3 VA at FB201.
2) If 3.3 VA is ok, please check OPT_IN signal (R201) when optical mode.
3) If signal is abnormal, replace JACK board.

2-2-3. Service hint (Any picture / Remark)




JK201

 FB201

< JACK board top view >

3-10 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
NO SOUND

2-3. HDMI
2-3-1. Solution
Replace JACK board.

2-3-2. How to troubleshoot (Countermeasure)

1) Please check soldering status of HDMI jack and check HDMI_5.1VA at IC803 pin1.
2) If soldering status and 5.1 VA are abnormal, replace JACK board.

2-3-3. Service hint (Any picture / Remark)


IC803

IC800
< JACK board top view >

3-11 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
NO SOUND

2-4. Portable
2-4-1. Solution
Replace JACK board.

2-4-2. How to troubleshoot (Countermeasure)

1) Please check soldering status of portable jack and check IC200 pin3 (VCC_5V), pin4 (D_3.3V).
2) If portable jack and voltage has abnormal status, replace JACK board.

2-4-3. Service hint (Any picture / Remark)



FB203
FB202
IC200

< JACK board top view > < JACK board bottom view >

3-12 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
3. PROTECTION ERROR
No display or No Sound.

3-1. D(DC) PROTECTION

3-1-1. Solution
Replace MAIN board.

3-1-2. How to troubleshoot (Countermeasure)

1) Check DC voltage of speaker out FL+, FL-, TOP L+, TOP L-, SR L+, SR L+ (CN700 pin6, 5, 4, 3, 2, 1),
Center+, Center- (CN701 pin2, 1) and SR L+, SR L-, TOP R+, TOP R-, FR R+, FR R- (CN702 pin8, 7, 5,
4, 2, 1).
2) Check resistor crack, cold solder of AMP IC out (R718, R723, R724, R719, R7L9, R7L8, R7M1, R7M0,
R722, R720, R7L5, R7H1, R7K9, R7H9).
3) If AMP IC out is ok and speaker out has DC voltage, replace MAIN board.

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

CN702 CN701 CN700

< MAIN board top view >

3-13 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
PROTECTION ERROR
No display or No Sound.

3-2. S(SHUT DOWN) PROTECTION

3-2-1. Solution
Replace MAIN board.

3-2-2. How to troubleshoot (Countermeasure)

1) Check PVDD voltage (20 VA) of IC706, IC708, IC707, IC710 pin17, 18, 19, 31, 32.
- If PVDD voltage has 20 V under, refer to STEP 1-1.
2) Check impedance (4 Ω) of speaker unit.
- If impedance of speaker unit has 1 Ω under, replace speaker unit.
3) If check point 1), 2) is ok, replace MAIN board.

3-2-3. Service hint (Any picture / Remark)

IC710 IC707 IC708 IC706

< MAIN board top view >

3-14 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
PROTECTION ERROR
No display or No Sound.

3-3. B(BURNT) PROTECTION

3-3-1. Solution
Replace MAIN board.

3-3-2. How to troubleshoot (Countermeasure)

1) Check voltage 20 V of IC706, IC708, IC707, IC710 at pin17, 18, 19, 31, 32.
- If 12 V has problem refer to STEP 1-1.
2) If 20 V is OK, replace MAIN board.

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

IC710 IC707 IC708 IC706

< MAIN board top view >

3-15 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WAVEFORMS OF MAJOR CHECK POINT
1. CRYSTAL

1 2

Fig 1-1. Crystal Fig 1-2. Crystal

X501 (27 MHz) X801 (27 MHz)

3-16 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
CRYSTAL 2. FLASH

VCC

3 4
CS#
5

CLK
6

7 DO

Fig 1-3. Crystal Fig 2. Flash

X603 (12.288 MHz) VCC/ CS#/ CLK/ DO

3 5 4

7
6

3-17 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
3. REMOTE CONTROL

8 10

Fig 3-1. Remote Control Fig 3-3. Remote Control

Input Voltage High Timing

Item Measured Spec.

IR Receiver Spec:
Input Level 3.3 V
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

Fig 3-2. Remote Control

Low Timing

9 10 8

3-18 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
4. OPTICAL

11 12

Fig 4-1. Optical Fig 4-2. Optical

Opt In Opt Det

12

11

3-19 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
3-20 Copyright © 2018 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
CIRCUIT VOLTAGE CHART
1. ICs ICs
Location Name Pin No Pin Name Spec Measured Voltage Location Name Pin No Pin Name Spec Measured Voltage
IC100 MICOM 87, 38, 16, 64 VDD 1.8 V ~ 3.6 V 3.341 V 17 AVCC 4.5 V ~ 26 V 23.03 V
IC708 AMP
IC101 Serial Flash 8 VCC 2.7 V ~ 3.6 V 3.345 V 18, 19, 31, 32 PVCC 4.5 V ~ 26 V 23.01 V
IC102 Serial Flash 8 VCC 2.7 V ~ 3.6 V 3.342 V 17 AVCC 4.5 V ~ 26 V 22.99 V
IC710 AMP
5 VIN + 4.5 V ~ + 5.5 V + 5.087 V 18, 19, 31, 32 PVCC 4.5 V ~ 26 V 23.00 V
IC203 Switch
1 VOUT LPSBV 4.5 V ~ 5.5 V 5.053 V
2 VIN + 4.0 V ~ + 30 V + 23.02 V RXn1_PWR5V 4.5 V ~ 5.3 V 5.041 V
IC300 DC,DC
3 VOUT 0.8 V ~ 27 V 12.07 V SBVCC5 4.5 V ~ 5.5 V 5.07 V
1 VIN + 4.5 V ~ + 17 V + 12.05 V IO_VDD33 3.14 V ~ 3.46 V 3.325 V
IC301 DC,DC
2 VOUT 0.8 V ~ 10 V 1.216 V RX_AVDD33 3.14 V ~ 3.46 V 3.321 V
1 VIN + 4.5 V ~ + 17 V + 12.08 V TX0_AVDD33 3.14 V ~ 3.46 V 3.325 V
IC302 DC,DC IC800 HDMI
2 VOUT 0.8 V ~ 10 V 5.122 V RX_AVDD10 1.0 V ~ 1.1 V 1.046 V
4 VIN + 2.7 V ~ + 5.5 V + 5.091 V TXn_AVDD10 1.0 V ~ 1.1 V 1.042 V
IC303 DC,DC
3 VOUT 0.6 V ~ 5 V 3.364 V TXn_PVDD10 1.0 V ~ 1.1 V 1.044 V
5 VIN + 2.5 V ~ + 5.5 V + 3.339 V CVDD10 1.0 V ~ 1.1 V 1.043 V
IC304 Switch
1 VOUT CG0_PVDD10 1.0 V ~ 1.1 V 1.04 V
5 VIN + 2.5 V ~ + 5.5 V + 3.346 V RX_PVDD10 1.0 V ~ 1.1 V 1.041 V
IC305 Switch
1 VOUT IC801 Serial Flash 8 VCC 2.7 V ~ 3.6 V 3.341 V
3 VIN + 2.5 V ~ + 5.5 V + 5.121 V 5 VIN + 2.5 V ~ + 5.5 V + 3.346 V
IC306 LDO IC802 Switch
6 VOUT 1.5 V ~ 5 V 3.323 V 1 VOUT
1 VIN + 2.0 V ~ + 6.0 V + 3.315 V 5 VIN + 4.5 V ~ + 5.5 V + 5.079 V
IC307 LDO IC803 Switch
5 VOUT 0.8 V ~ 5 V 1.212 V 1 VOUT
5 VIN + 2.5 V ~ + 5.5 V + 3.341 V 1 VIN + 4.5 V ~ + 17 V + 5.15 V
IC308 Switch IC804 DC,DC
1 VOUT 2 VOUT 0.8 V ~ 10 V 1.121 V
4 VIN + 2.7 V ~ + 5.5 V + 5.08 V
IC309 DC,DC
3 VOUT 0.6 V ~ 5 V 3.51 V
4 VIN + 2.7 V ~ + 5.5 V + 5.07 V
IC310 DC,DC
3 VOUT 0.6 V ~ 5 V 1.512 V
4 VIN + 2.7 V ~ + 5.5 V + 5.5 V
IC312 DC,DC
3 VOUT 0.6 V ~ 5 V 1.217 V
2. CAPACITORS
K12 DVCC12 1.14 V ~ 1.26 V + 1.213 V
G14 DVCC33 3.15 V ~ 3.45 V + 3.345 V Location Spec Measured [V]
N23 AVDD12 1.14 V ~ 1.26 V + 1.218 V C707 330uF/35V (105/ 2000HR) +23.12V
IC501 MPEG
R26 AVDD33 3.15 V ~ 3.45 V + 3.342 V C708 330uF/35V (105/ 2000HR) +23.12V
AC3 DDRVCCIO1
C710 330uF/35V (105/ 2000HR) +23.12V
N8 DDRVREF
C711 330uF/35V (105/ 2000HR) +23.12V
IC503 DDR3 SDRAM VIN + 2.8 V ~ + 5.5 V + 3.427 V
C712 330uF/35V (105/ 2000HR) +23.12V
IC504 DDR3 SDRAM VIN + 2.8 V ~ + 5.5 V + 3.421 V
IC505 NAND VCC - 0.6 V ~ + 4.6 V + 3.344 V C7U9 330uF/35V (105/ 2000HR) +23.12V
VDD_INT 1.05 V ~ 1.15 V 1.128 V C7V3 330uF/35V (105/ 2000HR) +23.12V
VDD_EXT 3.13 V ~ 3.47 V 3.341 V
IC601 DSP
VDD_DMC 1.425 V ~ 1.575 V 1.522 V
VDD_USB 3.13 V ~ 3.47 V 3.348 V
IC602 Serial Flash 8 VCC 2.7 V ~ 3.6 V 3.343 V
13, 21, 25, 47 VDD 1.14 V ~ 1.26 V + 1.216 V
IC705 DAC 20, 48 DVCC 3.135 V ~ 3.465 V + 3.351 V 3. CONNECTORS
6, 14, 24, 31 AVCC 3.135 V ~ 3.465 V + 3.332 V
Test Connector Spec Connector (Main) Mating Connector
17 AVCC 4.5 V ~ 26 V 23.01 V
IC706 AMP Bluetooth CN102 (PIN10) 3.0 V ~ 3.6 V 3.347 V 3.345 V
18, 19, 31, 32 PVCC 4.5 V ~ 26 V 23.03 V
17 AVCC 4.5 V ~ 26 V 23.00 V Wi-Fi CN501 (PIN1) 2.97 V ~ 3.63 V 3.421 V 3.389 V
IC707 AMP
18, 19, 31, 32 PVCC 4.5 V ~ 26 V 22.98 V Wireless (Subwoofer) CN104 (PIN1) 3.0 V ~ 3.6 V 3.344 V 3.349 V

3-21 3-22 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
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.

3-23 3-24 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2. MAIN P. C. BOARD DIAGRAM
(TOP VIEW)

3-25 3-26 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
MAIN P. C. BOARD DIAGRAM
(BOTTOM VIEW)

3-27 3-28 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
3. JACK P. C. BOARD DIAGRAM
(TOP VIEW) (BOTTOM VIEW)

3-29 3-30 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
4. FRONT P. C. BOARD DIAGRAM
(TOP VIEW) (BOTTOM VIEW)

5. TOUCH KEY P. C. BOARD DIAGRAM

(TOP VIEW) (BOTTOM VIEW)

3-31 3-32 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SECTION 4
WIRELESS SUBWOOFER PART

CONTENTS

WIRING DIAGRAM ............................................................................................................................................ 4-2

BLOCK DIAGRAM ............................................................................................................................................ 4-3

ONE POINT REPAIR GUIDE ............................................................................................................................ 4-4

1. POWER ON ERROR .............................................................................................................................. 4-4
2. WIRELESS CONNECTION .................................................................................................................... 4-6

WAVEFORMS OF MAJOR CHECK POINT...................................................................................................... 4-7

1. CRYSTAL ................................................................................................................................................ 4-7
2. FLASH MEMORY ................................................................................................................................... 4-7
3. VOLTAGE ............................................................................................................................................... 4-8
4. AMP VOLTAGE ...................................................................................................................................... 4-9
5. PWM ..................................................................................................................................................... 4-10
6. LED ....................................................................................................................................................... 4-11

CIRCUIT VOLTAGE CHART ........................................................................................................................... 4-13

PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 4-15

1. WOOFER SMPS & AMP P. C. BOARD ............................................................................................... 4-15

4-1 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WIRING DIAGRAM

2P, 3.96mm
ST, Non Lock SMD

Wireless
26P, 0.5mm
ST, Non Lock SMD

2P, 3.96mm
ST, Non Lock , SMD

Power

4-2 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 BLOCK DIAGRAM

Wireless
TX

LED (RED, GREEN)

Wireless AMP_PDN

RX AMP_SD
PAIRING

Reset KEY

I2C I2S

LPF FL

SW+/SW-

PWM IC AMP IC LPF FR

4-3 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
1. POWER ON ERROR
Fundamental power check points.

1-1. 12 V
1) Check 12 V at WL708.
2) If 12 V is not checked at the point, then find PVDD at pin7 of WIC704.
3) 1), 2) is NG  Replace WIC704.

If you can’t check PVDD voltage, then replace the PCB board.

WIC704

WL708

< Woofer SMPS & AMP board top view >

1-2. 3.3 VA
1) Check 3.3 VA at WL707 coil.
2) If 3.3 VA is not checked at the point, then find 12 VA at pin3 of WIC705.
3) 1), 2) is NG  Replace WIC705.

If you can’t check 12 VA voltage, refer to the step 1-1.

WL707

WIC705

< Woofer SMPS & AMP board top view >

4-4 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
POWER ON ERROR
Fundamental power check points.

1-3. 3.3 VA
1) Check 3.3 VA at pin1 of WIC703.
2) Check 3.3V_PWM at pin6 of WIC703.
3) 1), 2) is NG  Replace WIC703.

If you can’t check PVDD voltage, then replace the PCB board.

WIC703

< Woofer SMPS & AMP board bottom view >

4-5 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
2. WIRELESS CONNECTION
Wireless connection malfunction.

2-1. 3.3 VA
1) Check 3.3 VA at WFB604.

2-2. Connection
1) Wireless module connection closely.
2) Implement Wireless Factory Reset.
 MAIN SET : Soundbar vol MIN and push Mute key (sustain 3 ~ 5 seconds).
 Subwofer :  Press Pairing button on the rear of the wireless subwoofer.
    The LED of of the wireless subwoofer blink red and green, pull out power cord.
    The main set and the wireless subwoofer are factory reset mode, then power on.

WFB604
Wireless module
Connection check

< Woofer SMPS & AMP board top view >

4-6 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WAVEFORMS OF MAJOR CHECK POINT
1. CRYSTAL

FIG 1. WX601 (24.576 MHz)

2. FLASH MEMORY

VCC
2

CS#
3

CLK 3 5
4

DO
5

FIG 2. VCC, CS#, CLK, DO

2 4

4-7 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
3. VOLTAGE

6 7

FIG 3-1. Woofer PVDD FIG 3-2. Woofer 12 VA

8 6

FIG 3-3. Woofer 3.3 VA

FIG 3-4. Woofer 3.3V_PWM

4-8 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
4. AMP VOLTAGE

10 11

FIG 4-1. AMP PVDD FIG 4-2. AMP_12V

11 10

4-9 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
5. PWM

12 13

FIG 5-1. Woofer PWM SW+ Signal FIG 5-2. Woofer PWM SW- Signal

12

13

4-10 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
6. LED

14 15

FIG 6-1. Pairing Off Status  Red LED FIG 6-2. Pairing On Status  Green LED

14

15

4-11 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
4-12 Copyright © 2018 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
CIRCUIT VOLTAGE CHART

Location No. Description Pin Number Specification Real Value (#1, #2)
VDD _IO: VDD_IO:
3.37 V 3.37 V
#17, 43, 52 2.97 V ~ 3.63 V
IC,
VDD_CORE: VDD_CORE:
WIC601 Sound/Audio 1.27 V 1.27 V
#6, 25, 63 1.08 V ~ 1.32 V
Processor
VDD_PLL:
VDD_PLL: #68 1.28 V 1.28 V
1.08 V ~ 1.32 V
PVDD:
PVDD:
#29, 30, 31, 20.61 V 20.64 V
12 V ~ 34 V
36, 37, 38
IC,
WIC701 GVDD:
Audio Amplifier GVDD: #1, 22 12.41 V 12.42 V
10.8 V ~ 13.2 V
VDD:
VDD: #2 12.47 V 12.47 V
10.8 ~13.2V
VIN:
VIN: #1 3.42 V 3.42 V
IC, 2.8 V ~ 5.5 V
WIC703
Analog Switch VOUT:
VOUT: #6 3.41 V 3.41 V
2.8 V ~ 5.5 V
VIN:
VIN: #7 34.61 V 34.64 V
IC, 4.5 V ~ 45 V
WIC704
DC,DC Converter VOUT:
SW: #1 12.53 V 12.53 V
0.8 V ~ 42 V
VIN:
VIN: #3 12.52 V 12.52 V
IC, 4.5 V ~ 17 V
WIC705
DC,DC Converter VOUT:
SW: #2 3.42 V 3.42 V
0.76 V ~ 7 V

4-13 4-14 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
PRINTED CIRCUIT BOARD DIAGRAMS
1. WOOFER SMPS & AMP P. C. BOARD
(TOP VIEW) (BOTTOM VIEW)

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

4-15 4-16 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 SECTION 5
WIRELESS RECEIVER PART
(OPTION)

CONTENTS
WIRING DIAGRAM ............................................................................................................................................ 5-2

BLOCK DIAGRAM ............................................................................................................................................ 5-3

ONE POINT REPAIR GUIDE ............................................................................................................................ 5-4

ELECTRICAL TROUBLESHOOTING GUIDE................................................................................................... 5-5

WAVEFORMS .................................................................................................................................................... 5-7

PRINTED CIRCUIT BOARD DIAGRAMS ......................................................................................................... 5-9

1. WIRELESS RECEIVER SMPS P. C. BOARD .......................................................................................... 5-9
2. WIRELESS RECEIVER AMP P. C. BOARD .......................................................................................... 5-11

5-1 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WIRING DIAGRAM

SPK(RR/RL)

SPK terminal

10P Harness
RJK301

RCN301

CN901
Rear AMP

SMPS
R
C
N
3
0
3
26P FFC
Wireless

5-2 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 BLOCK DIAGRAM

Wireless
TX

LED (RED, GREEN)

Wireless AMP_PDN

RX AMP_SD
PAIRING

Reset KEY
I2C I2S

RL
LPF

RL+,-/RR+,-
AMP RR
LPF
PWM IC

5-3 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
1. How to Duplicate Problem
Wireless rear speaker doesn’t output a sound.

1-1. Solution
Replace SMPS board (No PVDD).

1-2. How to troubleshoot (Countermeasure)

Check LED color of RX BOX.

YES
Color is yellow? Replace SMPS board.
NO

Try to remate or reset.

2. How to Duplicate Problem

Wireless rear speaker doesn’t output a sound.

2-1. Solution
Replace AMP board (No 12 V).

2-2. How to troubleshoot (Countermeasure)

AMP 12 V YES 14 VA YES

(RIC308 pin4) (RIC308 pin2) Replace SMPS board.
no output. no input.

NO NO

Check 3.3 V. Replace AMP board.

2-3. Service hint (Any picture / Remark)

RIC308

RIC307

< AMP board top view >

5-4 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ONE POINT REPAIR GUIDE
3. How to Duplicate Problem
Wireless rear speaker doesn’t output a sound.

3-1. Solution
Replace AMP board (No 3.3 V).

3-2. How to troubleshoot (Countermeasure)

PWM 3.3 V YES 5 VA YES

(RIC307 pin3) (RIC307 pin2) Replace SMPS board.
no output. no input.

NO NO

Check Module or connection. Replace AMP board.

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

RIC308

RIC307

< AMP board top view >

5-5 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 ELECTRICAL TROUBLESHOOTING GUIDE
No Pairing

Check LED status.

Yellow LED blinks irregularly.

YES
interference. Turn off the equipment that
gives interference.
NO

YES
Red LED is turned on. Remate.
NO

Check SMPS board or

Module connection.

No Sound

Check sound status.

Sound cut off irregularly.

YES
interference. Turn off the equipment that
gives interference.
NO

Check LED status.

YES
LED is Red. Remate.
NO

AMP PVDD YES

Check SMPS board.
(RCN301 pin9, 10) no output.
NO

AMP 12 V (RIC308 pin4) YES

Check RIC308.
no output.
NO

3.3 V (RIC307 pin3) YES

Check RIC307.
no output.

Check Module or Connection.

5-6 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
 WAVEFORMS
1. AUDIO PART (I2S)

RCN303 pin1 : I2S LRCK

1
2

RCN303 pin3 : I2S BCK

RCN303 pin20 : I2S Audio Data

5-7 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
5-8 Copyright © 2018 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
PRINTED CIRCUIT BOARD DIAGRAMS
1. WIRELESS RECEIVER SMPS P. C. BOARD
(TOP VIEW) (BOTTOM VIEW)

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

5-9 5-10 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.
2. WIRELESS RECEIVER AMP P. C. BOARD
(TOP VIEW) (BOTTOM VIEW)

5-11 5-12 Copyright © 2018 LG Electronics Inc. All rights reserved.

Only for training and service purposes.