SERVICE MANUAL
MODEL: RN9
Mini Hi-Fi Audio
SERVICE MANUAL
MODEL: RN9
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
P/NO : AFN30014625
MARCH, 2020
“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 © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
CONTENTS
SECTION 1 ........ GENERAL
SECTION 2 ........ CABINET & MAIN CHASSIS
SECTION 3 ........ ELECTRICAL
1-1
Copyright © 2020 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
HIDDEN KEY MODE ......................................................................................................................................... 1-5
1. HIDDEN KEY MODE TABLE
2. HIDDEN KEY MODE DESCRIPTION
PROGRAM DOWNLOAD GUIDE...................................................................................................................... 1-6
1. MAIN MCS PROGRAM (MAIN MCS CHIP)
2. MICOM PROGRAM
3. OPTION & EQ PROGRAM
FOTA UPDATE STEP USING BT APP ............................................................................................................ 1-9
SPECIFICATIONS ........................................................................................................................................... 1-11
1-2
Copyright © 2020 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 designators 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, implementation of the latest safety and performance improvement changes into the set is
not delayed until the new service literature is printed.
CAUTION : Do not attempt to modify this product in any way. Never perform customized installations without manufacturer’s approval. Unauthorized modifications
will not only void the warranty, but may lead to property damage or user injury.
Service work should be performed only after you are thoroughly familiar with these
safety checks and servicing guidelines.
GRAPHIC SYMBOLS
The exclamation point within an equilateral triangle is intended to alert
the service personnel to important safety information in the service
literature.
The lightning flash with arrowhead symbol within an equilateral
triangle is intended to alert the service personnel to the presence of
noninsulated “dangerous voltage” that may be of sufficient magnitude
to constitute a risk of electric shock.
The pictorial representation of a fuse and its rating within an equilateral triangle is intended to convey to the service personnel the following fuse replacement caution notice:
CAUTION : FOR CONTINUED PROTECTION AGAINST RISK
OF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND
RATING AS MARKED NEAR EACH FUSE.
SERVICE INFORMATION
While servicing, use an isolation transformer for protection from AC line shock. After
the original service problem has been corrected, make a check of the following:
TIPS ON PROPER INSTALLATION
1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelf
space over, or close to, a heat duct, or in the path of heated air flow.
2. Avoid conditions of high humidity such as: outdoor patio installations where dew
is a factor, near steam radiators where steam leakage is a factor, etc.
3. Avoid placement where draperies may obstruct venting. The customer should
also avoid the use of decorative scarves or other coverings that might obstruct
ventilation.
4. Wall- and shelf-mounted installations using a commercial mounting kit must follow
the factory-approved mounting instructions. A product mounted to a shelf or platform must retain its original feet (or the equivalent thickness in spacers) to provide
adequate air flow across the bottom. Bolts or screws used for fasteners must not
touch any parts or wiring. Perform leakage tests on customized installations.
5. Caution customers against mounting a product on a sloping shelf or in a tilted
position, unless the receiver is properly secured.
6. A product on a roll-about cart should be stable in its mounting to the cart.
Caution the customer on the hazards of trying to roll a cart with small casters
across thresholds or deep pile carpets.
7. Caution customers against using extension cords. Explain that a forest of extensions, sprouting from a single outlet, can lead to disastrous consequences to
home and family.
FIRE AND SHOCK HAZARD
1. Be sure that all components are positioned to avoid a possibility of adjacent component 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 electrical 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, conduit, 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 constitutes a potential shock hazard and must be corrected immediately.
1-3
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
SERVICING PRECAUTIONS
CAUTION: Before servicing the Audio products covered by this
service data and its supplements and addends, read and follow the SAFETY PRECAUTIONS.
NOTE: if unforeseen circumstances create conflict between
the following servicing precautions and any of the safety
precautions in this publication, always follow the safety precautions.
Remember Safety First :
General Servicing Precautions
1. Always unplug the Audio products AC power cord from the
AC power source before:
(1) Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2) Disconnecting or reconnecting any internal electrical
plug or other electrical connection.
(3) Connecting a test substitute in parallel with an electrolytic capacitor.
Caution: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an
explosion hazard.
2. Do not spray chemicals on or near this Audio products or any
of its assemblies.
3. Unless specified otherwise in this service data, clean electrical contacts by applying an appropriate contact cleaning
solution to the contacts with a pipe cleaner, cotton-tipped
swab, or comparable soft applicator.
Unless specified otherwise in this service data, lubrication
of contacts is not required.
4. Do not defeat any plug/socket B+ voltage interlocks with
which instruments covered by this service manual might be
equipped.
5. Do not apply AC power to this Audio products and / or any
of its electrical assemblies unless all solid state device heat
sinks are correctly installed.
6. Always connect the test instrument ground lead to an
appropriate ground before connecting the test instrument
positive lead. Always remove the test instrument ground
lead last.
Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and turn
the power on. Connect an insulation resistance meter (500V)
to the blades of the attachment plug. The insulation resistance between each blade of the attachment plug and accessible conductive parts (Note 1) should be more than 1Mohm.
Note 1: Accessible Conductive Parts include Metal panels,
Input terminals, Earphone jacks,etc.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged
easily by static electricity. Such components commonly are
called Electrostatically Sensitive (ES) Devices. Examples
of typical ES 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 ES
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
ES 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 ES devices.
5. Do not use freon-propelled chemicals. These can generate
an electrical charge sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install
it. (Most replacement ES devices are packaged with leads
electrically shorted together by conductive foam, aluminum
foil, or comparable conductive material).
7. Immediately before removing the protective material from
the leads of a replacement ES device, touch the protective
material to the chassis or circuit assembly into which the
device will be installed.
Caution: Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Normally 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 ES device.)
1-4
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
HIDDEN KEY MODE
1. HIDDEN KEY MODE TABLE
HIDDEN MODE
ENTRANCE KEY(Audio)
EXIT KEY
Version Check
Front ‘Stop’ 
+ Remote Control Key ‘Play’ / for 5s
Remote Control Key ‘Play’ / for 1.5s
EEPROM INITIAL
Front ‘Stop’ 
+ Remote Control Key ‘
Auto exit
‘ for 5s
2. HIDDEN KEY MODE DESCRIPTION
2-1. Version Check
- Function : Version Check.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘Play’ for 5s.
- Exit Key : Remote Control Key ‘Play’ for 1.5s.
- Operation explanation : Remote Control Key OR .
VFD Display (Example)
Result
MCS Version
MICOM Version
OPTION Version
DEMO Version
DJ PRO Version
EQ Version
EQ Check sum Version
2-2. EEPROM Initial
- Function : Initialize data stored in EEPROM and BACKUP RAM data.
- Entrance Key : Front ‘Stop’ + Remote Control Key ‘ ‘ for 5s.
- Exit Key : Auto exit.
- Explanation : ‘E2P CLR’ is displayed on the VPD and turn off the power automatically.
1-5
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
PROGRAM DOWNLOAD GUIDE
1. MAIN MCS PROGRAM (MAIN MCS CHIP)
Download program file name must be MAIN_RN9_RN7_RN5_HAC_YYMMDDX.bin
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds at USB1 function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device.
2) Copy Firmware file to USB device.
NO USB

Insert USB device into USB1 port at USB1 function.
SEARCH

MAIN FIRMWARE

FINISH

Auto POWER OFF
1-6
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
2. MICOM PROGRAM
Download program file name must be MICOM_ON_RN_HAC_YYMMDDX.HEX
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds at USB function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device.
2) Copy Firmware file to USB device.
NO USB

Insert USB device into USB1 port at USB1 function.
SEARCH

MICOM UP

FINISH

Auto POWER OFF
1-7
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
3. OPTION & EQ PROGRAM
Download program file name must be OPTEQ_RNx_HAC_YYMMDDX.BIN
(*RNx : “RN9”, “RN7” or “RN5”, depends on model option.)
If security program(Water Wall) is activated on PC, you must save the file to the USB storage device
and disable the security software, then download the file to your set.
Downloading file proceeds at USB function.
Caution: When downloading the file, you should neither unplug the USB device, change to the other function,
nor power off the device. USB device must be unplugged when the downloading process is completed.
ON VFD DISPLAY SCREEN
1) (Fast) Format USB device.
2) Copy Firmware file to USB device.
NO USB

Insert USB device into USB1 port at USB1 function.
SEARCH

OPT UP

EQ UP

FINISH

Auto POWER OFF
1-8
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
FOTA UPDATE STEP USING BT APP
Step1 : App connecting
Step2 : Device version info
(Check FW version)
After connecting the BT App with SET,
the user could find the “Device Version info” on
Setting tab.
When touch the “Device Version info” button,
user could find the current and latest SET
version on pop-up menu.
Step3 : Select update button
Step4 : Confirm update
When touch the “Update” button, user could
update the SET firmware using FOTA.
Select the OK button on the caution message.
1-9
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
Step5 : Download from CDN server
Step6 : Transfer FW
1st step is download from CDN server to
smart phone. The progress bar is displayed
on BT App.
After completed the download from server,
smart phone start to transfer the firmware to the
SET. The progress bar is displayed on BT App.
Step7 : FW Flash Writing
Step8 : FOTA complete
After completed the download from the smart
phone, the SET overwrite the firmware to flash
memory.
When finishing the flash memory writing, pop-up
message about finish is displayed and the SET
auto power off.
1-10
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
SPECIFICATIONS
 GENERAL
Power requirements
Power consumption
Dimensions (W x H x D)
Operating temperature
Operating humidity
Refer to the main label on the unit.
Refer to the main label on the unit.
Approx. 330.0 mm x 1,056.0 mm x 368.0 mm
5 °C to 35 °C
5 % to 60 % RH
 INPUTS
Digital audio in (OPTICAL IN)
Microphone (MIC IN) Sensitivity
Guitar (GUITAR IN) Sensitivity
3.3 V (p-p), Optical jack x 1
20 mV (1 kHz), 6.3 mm jack x 1
190 mV (1 kHz), 6.3 mm jack x 1
 TUNER
FM Tuning Range
DAB Tuning Range
87.5 to 108.0 MHz or 87.50 to 108.00 MHz
174.928 to 239.2 MHz
 SYSTEM
Frequency Response
Signal-to-noise ratio
Dynamic range
Bus Power Supply (USB)
Available Digital Input Audio Sampling Frequency
Available Digital Input Audio format
250 to 20,000 Hz
More than 80 dB
More than 80 dB
5V
500 mA
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
Dolby Audio, PCM
 Design and specifications are subject to change without notice.
1-11
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
1-12
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
DISASSEMBLY INSTRUCTIONS ..................................................................................................................... 2-2
MD FFC INSERTION GUIDE........................................................................................................................... 2-10
EXPLODED VIEWS ......................................................................................................................................... 2-11
1. CABINET AND MAIN FRAME SECTION ............................................................................................... 2-11
2. PACKING ACCESSORY SECTION ....................................................................................................... 2-15
2-1
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
DISASSEMBLY INSTRUCTIONS
1) Remove the 6 screws.
Figure 1. Panel Side L/R disassembly - 1
2) Disassemble each of the 2 screws located inside the handle.
Figure 2. Panel Side L/R disassembly - 2
2-2
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
3) Pull out Cover Side Assembly L/R in the backward direction.
Figure 3. Panel Side L/R disassembly - 3
4) Remove the 3 screws.
Figure 4. Panel Top disassembly - 1
2-3
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
5) Remove the 2 screws on the left and right sides and then FFC cable of TOP PCBA.
Figure 5. Panel Top disassembly - 2
6) As shown in the figure, remove the Panel Top by pushing the front part and lifting the rear part.
1
2
Figure 6. Panel Top disassembly - 3
2-4
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
7) Remove the 4 screws on the Panel Rear.
Figure 7. Panel Rear disassembly
8) Bracket MD + Frame Main Screw 7 EA Disassembly.
Used Long length Driver
(300mm more than)
Figure 8. Main Set disassembly - 1
2-5
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
9) Remove the IR Receiver & Speaker LED Connector / Speaker Network cable.
Figure 9. Main Set disassembly - 2
10) Power Cable Disconnection
Figure 10. Main Set disassembly - 3
2-6
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
11) Grasp both sides and pull upward to remove the assembly.
Figure 11. Main Set disassembly - 4
12) Complete removal of the Main Set.
Figure 12. After detaching the Main Set
2-7
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
1. HOW TO DISASSEMBLE THE TOP PANEL
1) Remove the 13 screws on the left and right of the back.
2) Remove the side cover and remove the 2 screws on the left and right.
X
3) If you lift the top panel slightly with a rubber mallet or palm while lifting the back panel slightly,
you can disassemble it without damaging the hook.
Disassemble the FFC cable before disassembling the top cover.
When assembling the top cover, connect the FFC cable after assembling.
2-8
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
2. HOW TO DISASSEMBLE THE FRONT PANEL
1) Remove the 8 screws with the side cover and the top panel removed.
The two front screws are located deep.
Use a long driver (Lenght: 300 mm or more).
2) Remove the 8 screws to separate the speaker and the set part.
3) Remove the 2 top screws and 4 left and right screws.
4) You can remove the front panel by releasing the upper 2 hooks and the 4 left and right hooks and
releasing the lower 4 hooks.
2-9
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
MD FFC INSERTION GUIDE
1. Insert FFC Cable_Pick Up into Connector_Pick Up until it is no longer inserted vertically.
(Also, insert FFC Cable_Loading into Connector_Pick Up with the same disinfection.)
2. Insert as shown in 1 and check the FFC Cable Line level of A based on B.
(A and B do not always match. )
FFC Cable_Pick UP
FFC Cable_Loading
Connector_ Loading
A : FFC Cable Line
B : Connector
Connector_Pick Up
))&/LQH
))&/LQH
&RQQHFWRU
&RQQHFWRU
Case 1 : OK
))&/LQH
))&/LQH
&RQQHFWRU
&RQQHFWRU
Case 2 : NG
2-10
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION
256
CABLE9
A53
A30
P
P
I
A
G
A46
I
A44
D
E
F
270
C
MAIN
A47
J
J
D
SMPS
B
A50
269
C
H
H
CABLE1
A
CNT803
E
276
TOP
A60
251
A31
251
A51
BT
CABLE3
B
261
2-11
2-12
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
• Cabinet and main frame parts list
S
AL
LOCA. NO.
PART NO.
DESCRIPTION
SPECIFICATION
REMARKS
ASSEMBLY PARTS
A30
ACQ30004902
Cover Assembly
HOME OM9 COVER SIDE ASSY_L_Reg
A31
ACQ30004801
Cover Assembly
HOME OM9 COVER SIDE ASSY_R
A44
ACQ30004504
Cover Assembly
HOME RN9/7/5 COVER TOP ASSY(RD
A46
EBR30715307
Option Code Assembly
91 53 05 26 05 00 00 52 4E 39
A47
EBR30647402
PCB Assembly,Power
[ON9/RN9] [220 Narrow (200-240
A50
EBR89579701
PCB Assembly
ON9/7/5 Top PCB Total
A51
EAT62833604
Module,Bluetooth
MB8811C1TN CSR8811 Argentina H
A53
EBR30137501
PCB Assembly
DAB_Module OM9/OM7/RM7/OM5/RM5 only EU EVENT -
A60
AAX76968201
Board Assembly
HOME OM9 SPK PANEL+WOOD ASSY
251
MGJ66911201
Plate,Ground
256
MEY65334201
Knob
MOLD ABS H-121H HOME RM7C MOLD
261
AGL30003901
Panel Assembly,Front
HOME RM9/7/5 SET_PANEL FRONT A
269
EAL60700914
Fan Module
2D82ES1L0040 2.5KRPM DC 12V 10
270
MGC66105506
Panel,Rear
PRESS SECC 0.8 HOME RN9 PRESS
276
MEG63540502
Holder
INDIVISUAL PARTS
PRESS SUS 0.3 TOP PCB
MOLD ABS HOME MINI/Onebody MOL
CABLES
CABLE1
EAD60718903
Cable,FFC
16P125D-H02-1F01A-N 140 140MM
CABLE3
EAD62130037
Cable,FFC
10P010D-H2-1F00A-T-200-0-0-0-0
CABLE9
EAD65648201
Harness,Single
12507WS-H12G to 12507WS-H12G 80mm
CNT803
EAD42004424
Harness,Single
HS-LG16-020 12005HOO-08PL 2200
2-13
2-14
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
2. PACKING ACCESSORY SECTION
300 Power Cable
825 FM Wire Antenna
900 Remote Control
2-15
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
• Packing accessory parts list
S
c
AL
LOCA. NO.
PART NO.
DESCRIPTION
SPECIFICATION
300
EAD64108401
Power Cord
DE-2P-AN-PA-1500-N-00-BK-EU/RU
825
EAA65845801
Antenna,T
SN190379 SINGLE 0DB 50OHM 3 1.
900
AKB75815318
Remote Controller Assembly
MA2 RM9/7/5 (EU/DAB+) CD MINI
2-16
REMARKS
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER ............................................................................................................................................ 3-2
2. NO BOOTING WHEN POWER ON THE SET........................................................................................ 3-4
3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..................................................................... 3-5
4. NO BOOTING IN USB FUNCTION ........................................................................................................ 3-6
5. NO SOUND ........................................................................................................................................... 3-10
ELECTRICAL TROUBLESHOOTING GUIDE................................................................................................. 3-16
1. POWER (SMPS) ................................................................................................................................... 3-16
2. MCS PART CHECK .............................................................................................................................. 3-19
3. PWM MODULATION CHECK ............................................................................................................... 3-20
4. POWER AMP PART CHECK ............................................................................................................... 3-21
5. TUNER / DAB FUNCTION CHECK ...................................................................................................... 3-22
6. TUNER FUNCTION CHECK................................................................................................................. 3-23
7. DOUBLE USB FUNCTION ................................................................................................................... 3-24
WAVEFORMS OF MAJOR CHECK POINT.................................................................................................... 3-25
1. DSP (IC501) .......................................................................................................................................... 3-25
2. SDRAM (IC502) .................................................................................................................................... 3-26
3. SERVO (IC401)..................................................................................................................................... 3-27
4. MOTOR DRIVER (IC400) ..................................................................................................................... 3-28
5. ADC (IC301).......................................................................................................................................... 3-29
6. USB (CN502) ........................................................................................................................................ 3-29
7. BLUETOOTH (CN504).......................................................................................................................... 3-30
WIRING DIAGRAM .......................................................................................................................................... 3-31
BLOCK DIAGRAM .......................................................................................................................................... 3-33
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-35
1. IC VOLTAGE......................................................................................................................................... 3-35
2. FAN MOTOR VOLTAGE ...................................................................................................................... 3-36
3. SMPS CAPACITOR & ZENER DIODE VOLTAGE............................................................................... 3-36
4. MAIN CAPACITOR VOLTAGE ............................................................................................................. 3-36
5. CONNECTOR VOLTAGE ..................................................................................................................... 3-37
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-39
1. SMPS P.C.BOARD DIAGRAM ............................................................................................................. 3-39
2. MAIN P.C.BOARD DIAGRAM .............................................................................................................. 3-41
3. TOP KEY P.C.BOARD DIAGRAM ........................................................................................................ 3-45
4. LIGHTING LED P.C.BOARD DIAGRAM .............................................................................................. 3-49
5. DAB MODULE P.C.BOARD DIAGRAM................................................................................................ 3-49
3-1
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
1. NO POWER
If the unit doesn’t work by no power problem, repair the set according to the following guide.
1-1. FUSE/ THERMISTOR/ BRIDGE DIODE
1-1-1. Solution
Please check and replace F901, TH901, BD901 on SMPS board.
1-1-2. How to troubleshoot (Countermeasure)
1) Check if the fuse F901 is open or short-circuit.
2) Check if the NTC thermistor TH901 is normal or open.
3) Check if the bridge diode BD901 is short-circuit by over current with a digital multi-meter.
1-1-3. Service hint (Any picture/ Remark)
< F901 >
If F901 is not short-circuit, replace
it with a same specifications one.
ON5/ RN5 : 5 A (Red)
ON7/ RN7 : 5 A (Red)
ON9/ RN9 : 8 A (Green)
< TH901 >
If TH901 is open,
replace it with a new one.
3-2
< BD901 >
If BD901 is short-circuit,
replace it with a new one.
ON5/ RN5 : GBL08
ON7/ RN7/ ON9/ RN9 : GBU606G or RBU605M
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO POWER
If the unit doesn’t work by no PVDD problem, repair the set according to the following guide.
1-2. FET
1-2-1. Solution
Please check and replace Q901, Q902 on SMPS board.
1-2-2. How to troubleshoot (Countermeasure)
1) Check the Drain-Source or Drain-Gate, Gate-Source Resistance of Q901~ Q902 with a digital multi-meter.
 If it is short condition, it’s destroyed.
Replace it with a new one. (Please replace 2 FET at the same time although several FET is OK)
* RN9 : Q901 + Q902 * RN7/ RN5 : Q901 Only.
1-2-3. Service hint (Any picture/ Remark)
< SMPS circuit >
3-3
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
2. NO BOOTING WHEN POWER ON THE SET
The set doesn’t work when press the power button on the top board or the remote control.
2-1. IC501
2-1-1. Solution
Replace MAIN board.
2-1-2. How to troubleshoot (Countermeasure)
1) Check the 5.1 VA (CN201) and 3.3 VA(IC202) in standby mode.
 If there is no 5.1 VA, check the SMPS and if doesn’t appear 3.3 VA, check the IC202.
2) Check +12 V, DVCC_5V and DVCC_3.3V when power on the set.
 If the set doesn’t work regardless of what the KEY3 changes high to low while pressing the power button.
X500 and X501 work normally but, if you can not power on the set, replace the IC501 with a new one
on the main board.
R5B95
C5B23
C5B24
R508
R5B102
R5B104
RA503
8 10 12 14 16
9 11 13 15 17
R5B6
C5B5 C5B2
X500
C5B34
ZD506
4
2
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
1
FL500
C5E2
A
C5E3
R5B33
R5B34
R5B52
R5B36
R5B48
R5B63
R505
R503
L5B8
C2B5
R5B28
R5D7
R5B45
R5B17 R5B24 R5B21
R5B15
R5B26
R5B29
R5B32
R5B38 R5B30
SOLDERING
R128
R127
R102
R5B1
C130 C131
R103 R104
C5B25
C5E6
ZD205
L206
C232
C230
R242
C233
R243
C274
R244
C277
R245
R112
R111
2019.12.13
EAX69094501 VER1.4
C246
C2A6
C108
R116
IC204
C106 C105
C177
C217
R109
R147
R129
C104
X500
(32.768 MHz)
5
6
7
IC501
R122
R101
RA102
ARD
146 (220X125)
MES
ZD501
C237
C102
C101
C103
C2C1
R5D10
R596
R5B5
C5B4
IC501
C107
L101
R5B94
3
R5B64
R5B65
R5B61
R5B60
R5B56
RX
C2B9
C5B18
X501
R5B4
R5B47 DFT_TX
R5B9 R5B7
R5B37
R5B8
R5B10
R5B11 R5B22
R5B42 R5B43
R5B44
KEY3
(R5B64)
ZD505
R5B53 R5B51 R5B106
C539
C5B11 C5B14
R5B70
R5B69
R5
R5
SF_M
R5B72 R5B73
R5B75 R5B74
L5B3
X501
(24 MHz)
RA501
SF_CS
I
SF_SCK
SF_MOSI
CN501
RA504
R5B98 R5B107 C5B6
2-1-3. Service hint (Any picture / Remark)
CN101
< MAIN board top view >
3-4
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET
When power on the set, any icons or characters on VFD are not displayed.
3-1. VFD (VFD801)
3-1-1. Solution
Replace TOP board.
3-1-2. How to troubleshoot (Countermeasure)
1) Check if VFD_12V, DVCC_3.3V and DV_5V are output from MAIN to VFD via the TOP board.
2) Check if the IC501 outputs VFD_CLK, VFD_STB, and VFD_DO to the TOP board(CNT804 pin6~8).
3) Check if the VFD grid current amplifier circuit on the TOP board.
Check the drive signal to the transistor’s(CNT804 pin6~8) base.
 If the control signals from VFD (SW) isn’t output, replace VFD with a new one.
VFD heat rays is RED : DVCC_5V(IC201 check) Voltage will be high than 5.5 V.
No VFD : VH(VFD801 pin27) will be not supply about 30 V.
No VFD : VFD 12 V will be not supply (Check Q205).
3-1-3. Service hint (Any picture / Remark)
about
12Vp- p
CN804 Base
< Waveform of the grid current driver>
< CN804 >
3-5
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
4. NO BOOTING IN USB FUNCTION
After you turn on power key and displayed message in the following order (HELLO  VOL XX  USB)
on VFD, it will not display other message on VFD, and it will not boot-up normally.
4-1. NO DVCC_3.3V, 1.2 VA
4-1-1. Solution
Replace MAIN board.
4-1-2. How to troubleshoot (Countermeasure)
1) Check voltage of IC202 AND IC205 pin4 on MAIN board.
 If IC202, IC205 pin4(about 5.1 V) Input 5.1 VA doesn’t come out, check 5.1 VA from SMPS board.
2) If IC202, IC205 pin4(about 5.1 V) is normal, check the PWR_CTRL(IC204 pin5) is high (about 3.3 V).
 If PWR_CTRL isn’t high, check pin D11 of IC501 & R5B78, R214, R233.
3) If PWR_CTRL is high, check R5B78 and if there’s no defective component then check IC204 pin1 short
with GND.
4) If 3.3 V(DVCC_3.3V) is normal, check 1.2 VA output(C221, C226, C287, C288, C229) voltage of IC205.
 If 1.2 VA of IC205 doesn’t come out, then replace IC205.
R5D10
R596
C613
RA601
C5E2
L205
C221
C215
IC205
R5D5
R5D8
C226
C207
IC201
R241
IC208
C273
R214
R233
ZD203
C297
C246
C209
C177
R245
C2A6
R218
R219
IC202
R208
IC204
L202
CN101
C279
R244
C276
R243
C274
ZD202
R242
C233
L203
R237
R238
C2D2
L212
C232
R207
C230
C218
C5E6
L206
C222
C5B25
C288
C229
IC204
R128
R127
R102
C2B5
R210
ZD205
C287
C2D1
IC202
L5B8
C277
C108
C2C12
C231
C214
C2C5
R221
C106 C105
R112
R111
IC205
IC506
R5B33
R5B34
R5B52
R5B36
R5B48
R5B63
R505
R503
R5B45
R5B17 R5B24 R5B21
R5B15
R5B28
R5B26
R5B29
R5B32
R5B38 R5B30
SOLDERING
C2C6
C284
IC501
M_SCL
R702
C705
D204
M
N
P
R
T
U
M_DATR602
C5E3
IC601
C612
R624
R625
R5B6
C5B5 C5B2
X500
C5B34
ZD506
R601
FL500
L
K
R710
R723
R726
C614
ZD501
R5B4
R628
R629
R611
IC701
MES
R621
R5B5
C5B4
P_DAT
R524 R612
P_SCL
R508
R5B94
C6
R6
R
C
C5B
R5B98
R5B10
4-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
3-6
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO BOOTING IN USB FUNCTION
After you turn on power key and displayed message in the following order (HELLO  VOL XX  USB)
on VFD, it will not display other message on VFD, and it will not boot-up normally.
4-2. CRYSTAL (X500)
4-2-1. Solution
Replace MAIN board.
4-2-2. How to troubleshoot (Countermeasure)
1) If 3.3 V & 1.2 V is normal, check reset ‘High’ of IC501 pin T12 on MAIN board.
 If CHIP_RESET isn’t high, check the IC505.
2) If CHIP_RESET is high, check the soldering status of 24 MHz crystal (X500).
3) If the crystal(X500) doesn’t oscillate, check R5B4, R5B6, C5B2, C5B5 around crystal(X500).
 If there’s no defective component, then replace X500.
R5B98 R5B107 C5B60
R5B95
C5B23
C5B24
RA503
R508
R5B94
R5D10
R596
R5B5
C5B4
R5B6
C5B5 C5B2
X500
ZD501
7
IC501
C5B34
R5B4
6
ZD505
C5B18
X501
X500
< Signal waveform >
4
X500
FL500
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
1
2
3
R5B64
R5B65
R5B61
R5B60
R5B56
C5E2
A
C5E3
IC501
S
45
21
15
FT_TX
5B7
5B8
2
R5B53 R5B51 R5B106
RX
ZD506
5
XO
C5B11 C5B14
R5B70
R5B69
8 10 12 14 16
9 11 13 15 17
R5B72 R5B73
R5B75 R5B74
XI
R5B9
R5B1
RA504
R5B102
R5B104
RA502
RA501
SF_CS
SF_MIS
4-2-3. Service hint (Any picture / Remark)
< MAIN board top view >
3-7
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO BOOTING IN USB FUNCTION
After you turn on power key and displayed message in the following order (HELLO  VOL XX  USB)
on VFD, it will not display other message on VFD, and it will not boot-up normally.
4-3. SERIAL FLASH (IC503)
4-3-1. Solution
Replace MAIN board.
4-3-2. How to troubleshoot (Countermeasure)
1) If the crystal(X500) does oscillate, check Serial Flash(IC503) on MAIN board.
 Check pin8(VCC), pin6(SCLK), pin1(CS), pin2(DO), pin5(DI) of below waveform.
2) If pin8, 6, 1, 2, 5 doesn’t come out, check damping resistor(R5B72, R5B73, R5B74, R5B75) of IC503.
 If damping resistor of IC503 is OK, then replace IC503. (it need to download program)
3) After change IC503, if It is still not below waveform, check IC501(DSP IC).
4-3-3. Service hint (Any picture / Remark)
TP516
TP511
TP34
TP8
TP4
TP3
TP515
TP507
R5B96
R5B97
C5B59
TP512
VCC
CS#
SCLK
SO
C5B58
C
C
R5D16
R5D15
R5D18
R5B25 C
C5B19
R506
R5D17
IC503
R5B62
R5D4
R5B101
R5D3
C5B36
C5B55
R5D11
R5B58
C5B31
C5B35
C5B37
R5D12
C5B49
C5B20
R5B83
R5B112 R5B116
L5B11
C5B45
C5B47
C5B22
L5B6
L5B12
IC503
IC502
5 R5D19
R5D9
R5B50
R5D20
R5B80
R5B78
< Signal waveform >
< MAIN board bottom view >
3-8
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO BOOTING IN USB FUNCTION
After you turn on power key and displayed message in the following order (HELLO  VOL XX  USB)
on VFD, it will not display other message on VFD, and it will not boot-up normally.
4-4. SDRAM (IC502)
4-4-1. Solution
Replace MAIN board.
4-4-2. How to troubleshoot (Countermeasure)
1) Check below waveform & soldering status of SDRAM (IC502) on MAIN board.
 If pin17(#CAS), pin18(#RAS), pin19(#CS), pin38(CLK), pin29(address), pin2(DQ) doesn’t come out,
check damping resistor ((R5B99, R5B100, R5B102, R5B104, R5B107).
2) If resistor is OK, then replace IC502(SDRAM).
3) After change IC502, if It is still not below waveform, check IC501(DSP IC).
4-4-3. Service hint (Any picture / Remark)
TP516
TP511
TP34
TP8
TP4
TP3
TP515
TP507
R5B96
R5B97
C5B59
TP512
da ta
IC502
C5B58
C5B52
C5B15 C5B32
C5B51
C245
C5B56
R5B80
R5B78
/ CS
R5B86
C5B53
R AS
R5B66 R5B84
R5B81
R5B23
R5B79
R5B77
R5B76
R513
L5B2
C5B8
R5B27
R5B31
R5B110
C5B42
TP517
C5B17
R5B71
R5B67
R5B88
C5B55
R506
R5B62
R5D4
R5B101
R5D3
C5B36
R5D16
R5D15
C5B38
C5B50
R5D18
R5B25 C5B40
C5B19
R5B103
R5D17
C5B31
C5B37
C5B35
R5D12
C5B49
C5B20
R5D11
R5B58
R5B83
R510
R5B16
R5B19
R5B14
R5B20
R5B12
RB117
R5B18
R5B46
DFT_RX
R5B13
R5B35
C5B57
C5B54
C5B48
L5B12
R5B112 R5B116
L5B11
C5B45
C5B47
C5B22
L5B6
IC503
IC502
5 R5D19
R5D9
R5B50
R5D20
V CC
Reset
a ddress
/WE
R5E8
R582
C5B7
C AS
R5B2
R5B3
R5B39 C556 C504
< Signal waveform >
< MAIN board bottom view >
3-9
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
5. NO SOUND
There is no sound output by DIGITAL AUDIO AMP DAMAGE, repair the set according to the following
guide.
5-1. DIGITAL AUDIO AMP DAMAGE
5-1-1. Solution
Replace MAIN board.
5-1-2. How to troubleshoot (Countermeasure)
1) Check PWM_FL±, PWM_FR± & PWM_SW± signals from IC601 to IC701 & 702 each input function.
 If no signal, check if I2S audio signals are entered to IC601.
2) Check PVDD.
 If PVDD is abnormal, check the SMPS.
3) Check AMP_12V for driving the gate of AMP IC.
a. All the powers are normal, but if AMP_12V is low, there is possible for AMP IC to be damaged.
b. Remove L706, L707 one by one.
When removed a inductance, if AMP_12V is recovered, the IC connected to it was damaged.
c. Replace the IC with a new one.
4) Check the impedance between IC701_OUT_A/OUT_B & GND.
a. If the impedance is 0 Ω, the IC must be damaged.
b. After removing the heat sink, replace it with a new one.
C480
R248
C776
C778
C388
L308
R474
R475
R329
C353 C351 R328 R5E9
R473
R471
Q709
R472
C481
R7
R758
C391
C390
C359
D701
C78
B
L707
C775
C779
Q208
R757
5-1-3. Service hint (Any picture/ Remark)
C7
C752
C741
R712 C721
L707
C713
C739
L706
R729
D703
R730
L706
R710
R723
R726
IC701
R628
R629
R621
IC601
R611
IC701
C765
C731
C615
R617
R626
R627
C740
R712A
R736 R733
R737 R734
R738 R735
C742
C736
ZD702
C735
R250
Q207
R247
C2C11
R624
R625
C613
RA601
C766
R744 R741
R743 R740
R742 R739
L205
2
C612
IC601
C732
R702
C705
< MAIN board top view >
3-10
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the USB Function, repair the set according to the following guide.
5-2. USB FUNCTION
5-2-1. Solution
Replace MAIN board.
5-2-2. How to troubleshoot (Countermeasure)
1) Check +5V_USB to USB board.
 If the Character ‘USB 1’ or ‘USB 2’ is turned on VFD, the voltage is okay, if so not, check USB_5V to
pin4, 5 of CN502.
2) Check USB D1± or USB D2± from MAIN board to TOP board.
a. Check 2.0_D1±signals(pin U7, U8 ) or 1.1_D1± signals(pin A7, A8 ) to IC501.
b. Check USB± signals to CN502(pin1, 2, 7, 8).
 If there is any trouble, check the power for IC207.
The power is normal but, if the signal waveform to the IC is distorted or no signal,
replace it with a new one.
3) Check if “Digital audio AMP block” on item 6-1 is normal.
5-2-3. Service hint (Any picture/ Remark)
JK301
R3
JK302
L312
D+
CN502
D-
CN502
3A1
C5B21
R5B115
C2B3
R5B95
C5B23
C5B24
C5B18
X501
R508
R5B94
R5D10
R596
R5B5
C5B4
R5B6
C5B5 C5B2
X500
ZD501
6
7
IC501
C5B34
R5B4
4
FL500
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
1
2
3
B64
B65
B61
B60
B56
IC501
C5E2
A
C5E3
SOL
TX
53 R5B51 R5B106
RX
ZD506
5
ZD505
R5B98 R5B107 C5B60
RA503
8 10 12 14 16
9 11 13 15 17
USB D-/D+ (CN502 pin1, 2 & pin7, 8)
< Waveform of USB D± signal >
TP521
C5B39
R5B99
R5B100
RA504
C5B33
R5B102
R5B104
C5E7
C5B26
C5B30
C5B44
SF_MISO
RA502
RA501
SF_CS
C5B43
C5B41
TP519
C271
TP520
TP522
R501
TP523
R504
TP518
L5B9
< MAIN board top view >
3-11
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the TUNER function, repair the set according to the following guide.
5-3. TUNER FUNCTION
5-3-1. Solution
Replace MAIN board.
5-3-2. How to troubleshoot (Countermeasure)
1) Check if TUNER_LR is entered from pin13, 14 of IC302 to IC301(pin27, 28)
 If no signals, check AVCC_3.3V for tuner power.
 Check if the tuner control signals (CLK, DAT, CE, RST, SLT) are entered from IC501 to IC302.
If it doesn’t work, replace IC302 with a new one.
2) Check if MCS_BCK, MCS_LRCK, & MCS_MCLK are entered from IC501 to IC201.
3) Check if ADC_DATA is entered from IC301 to IC501.
 If no signal, check AVCC_3.3V & DVCC_3.3V (ADC) for IC301. If is NG, replace it with a new one.
4) Check the following I2S audio signal flow from IC501 to IC601. (Refer to Item 6-2.)
 If there is any trouble, check the power for each IC.
The power is normal but, if the signal waveform to the IC is distorted or no signal,
replace it with a new one.
5) Check if the digital audio AMP block is okay. Refer to “Digital Audio AMP” guide on Item 6-1.
 If AMP is damaged, replace it with a new one.
5-3-3. Service hint (Any picture/ Remark)
C344
TP21
7
TP20
IC301
L320
C318
C317
C314
C313
C301 C305
C302 C306
L311
R235
C324
L309
C272
R223
C309
L301
C310
R305
C308
C346
L315
IC207
C307
L513
C270
TP511
C228
R309
IC301
R307
R306
R308
R313 R312
R318
TP313
C311
C312
C236
C225
TP301
C220
R519
C2B2
R521
R5D14 R5B55 R5D19
R5D9
R5B
IC505
C5B3
C382
C5B22
C608
< TUNER function signal flow >
D201
IC502
ZD503
C2A3
C2A4
TP310 TP302
TP304
TP312
TP311
609
R217
< MAIN board bottom view >
3-12
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the MIC IN function, repair the set according to the following guide.
5-4. MIC(Guitar) IN function
5-4-1. Solution
Replace MAIN board.
5-4-2. How to troubleshoot (Countermeasure)
1) Check MIC_SI & Guitar signal to pin1, 13 of IC303.
 If no signal, Check the signals to pin6 & 8 of CNA301 on the MIC & RMC board.
2) Check if MIC_SIG and GUITAR is input from pin3, 12 of IC303 to pin3, 4 of IC301 .
 If no signal output, check MIC_3.3V for IC303, replace IC303 with a new one if it has a problem.
3) Check if DSPI_BCK, LRCK,MCLK are entered from IC501 to IC301.
Check if MIC_DATA_IN is entered from pin19 of IC301 to pin E4 of IC501.
 If no signal, check AVCC_3.3V & DVCC_3.3V for IC301.
If it is abnormal, change replace it a new one.
4) Check the following I2S signal flow from IC301 to IC501.
 If there is any trouble, check the power for each IC.
If the signals are abnormal, replace it a new one.
5) Check if the digital audio AMP block is okay. Refer to “Digital Audio AMP” guide on item 6-1.
 If AMP is damaged, replace it with a new one.
JK303
5-4-3. Service hint (Any picture/ Remark)
44
TP21
L328
C383
R378
C372
R379
IC303
L326
C381
LG06
R369
C373
R383
C398
L329
C378
C391
C388
R301
ZD503
R302
C220
TP310 TP302
TP304
TP312
TP311
R248
D20
R521
R519
C2B2
R346
R309
C225
TP301
Pin15:DSPI_MCLK
Pin16:DSPI_LRCK
Pin17:DSPI_BCK
C2A3
C2A4
C353
R307
R306
R308
R313 R312
R318
TP313
C390
C359
Q208
C311
C312
C236
L308
R372
C371
C272
R223
C396
R235
C324
R305
C270
C228
R330
L313
6
5
C310
IC304
L301
R367
R366
R365
R
C393 362
R363
R360 R361
L309
IC207
C307
R359
IC303
R331
C318
C317
C399
C309
C387
C376
IC301
C308
C385
R371
C384
IC301
L320
C346
R382
C386
C301 C305
C302 C306
311
C337
L327
C397
C394
C314
C313
C380
C375 C389 C377 C379
R370
TP20
C395
R368
R381
R380 C336
L306
L325
C374
R373
RG06
R5D14 R5B
IC505
C5B3
C2C11
C382
< MAIN board top view >
< MAIN board bottom view >
3-13
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the Bluetooth function, repair the set according to the following guide.
5-5. BLUETOOTH FUNCTION
5-5-1. Solution
Replace MAIN board or bluetooth module.
5-5-2. How to troubleshoot (Countermeasure)
1) Check BT_RX, BT_TX signal to pin6, 4 of CN504.
 If no signal, check the signal to pin4, 6 and pin10 (3.3 VA) of on the Bluetooth module
and cable connection state.
 If there are no signal out from module, replace new module.
2) Check if BT_RX/TX is entered from pin6, 4 of CN504 to pin L1,K1 to IC501 (DSP).
3) Check if MCS_BCK, MCS_LRCK & MIX_DATA IN is entered from IC501 to IC601.
 If no signal, check +3.3 VA & +1.2 VA for IC501.
If it is abnormal, change replace it a new one.
4) Check the following I2S signal flow from IC501 to IC601.
 If there is any trouble, check the power for each IC.
If the signals are abnormal, replace it a new one.
5) Check if the digital audio AMP block is okay. Refer to “Digital Audio AMP” guide on item 6-1.
 If AMP is damaged, replace it with a new one.
5-5-3. Service hint (Any picture/ Remark)
R748
C758
B
C766
C753
B/T Module
R744 R741
R743 R740
R742 R739
C182
Q103
Q106
TP157
L110
TP156
CN106
PWM
MCS_BCK
MCS_LRCK
MIX_DATA0_OUT
R222
C185
Q101 Q102
Q104 Q105
C181
IC601
C180
IC501
LG07
TP155
TP154
C184
BT_RX,
BT_TX
TP158
L109
TP153
B
L108
C183
TP152
CN504
AMP
C509
C510
L505
L506
L507
L508
C561
< Bluetooth function signal flow >
C508
R5D1
C513 C515 C524 C532 C514 C522
R5D2
C512
L502
R246
CN504
< MAIN board top view >
3-14
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the OPTICAL function, repair the set according to the following guide.
5-6. OPTICAL FUNCTION
5-6-1. Solution
Replace MAIN board.
5-6-2. How to troubleshoot (Countermeasure)
1) Check DSPI_BCK, LRCK, MCLK, ADATA of IC304(pin27, 28, 29, 31).
 If no signal, check the signal from JK303 pin1 to IC304 pin1
and cable connection state.
 If there are no signal out from JK303, replace new connector and cable.
2) Check if MCS_BCK, MCS_LRCK & MIX_DATA IN is entered from IC501 to IC601.
 If no signal, check +3.3 VA & +1.2 VA for IC501.
If it is abnormal, change replace it a new one.
3) Check the following I2S signal flow from IC501 to IC601.
 If there is any trouble, check the power for each IC.
If the signals are abnormal, replace it a new one.
4) Check if the digital audio AMP block is okay. Refer to “Digital Audio AMP” guide on item 6-1.
 If AMP is damaged, replace it with a new one.
C399
R359
C788
C391
C390
L308
C388
Q208
R248
PWM
Q7
R329
C353 C351 R328 R5E9
IC601
MCS_BCK
MCS_LRCK
MIX_DATA_OUT
R757
R330
C359
IC501
Q706
R348
IC304
R755
R758
C387
C376
IC304
C348 C349
L329
C378
R382
C386
DSPI_MCLK
DSPI_LRCK
DSPI_BCK
DSPI_ADATA
R367
R366
R365
C393 R362
R363
R360 R361
R358
R355
C337
JK303
IC304
R380 C336
L306
C381
IC303
R
LG
5-6-3. Service hint (Any picture/ Remark)
R626
R627
R628
R629
R710
R723
701
4
R712 C721
R712A
R611
< OPTICAL function signal flow >
C713
ZD702
C615
3
4
R617
AMP
C605 R613 C601 R616
Q207
R247
R250
C2C11
< MAIN board top view >
3-15
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
1. POWER (SMPS)
No 12 VA
YES
F901 normal?
NO
Replace F901 (Use the same fuse).
YES
BD901 normal?
NO
Replace BD901.
YES
TH901 normal?
NO
Replace TH901.
YES
Is Vcc
(10 V ~ 18 V) supplied to
IC901 pin2?
NO
D902 normal?
NO
Check or replace D902.
YES
D921/ D922 normal?
NO
Replace D921/ D922.
YES
Is there
about 2.5 V at
IC941 pin1?
NO
Replace IC941.
YES
D951 normal?
NO
Replace D951.
YES
ZD932 normal?
NO
Replace ZD932.
YES
Power line of main PCB is short.
3-16
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
POWER (SMPS)
No PVDD
YES
F901 normal?
Model
PVDD
Fuse
FET
ON5/ RN5
34 V
5A
Q901
ON7/ RN7
47 V
5A
Q901
ON9/ RN9
58.5 V
8A
Q901, Q902
NO
Replace F901 (Use the same fuse).
YES
BD901 normal?
NO
Replace BD901.
YES
TH901 normal?
NO
Replace TH901.
YES
Is Vcc
(10 V ~ 18 V) supplied to
IC901 pin2?
NO
D903 normal?
NO
YES
Check or replace D903.
YES
NO
Q911 base HIGH?
YES
• Check P_CTRL HIGH signal from MCS.
• Check PC902.
Check or replace Q911.
Q901 or Q902 normal?
NO
Replace Q901 or Q902.
YES
D951 normal?
NO
Replace D951.
YES
Is there about 2.5 V
at IC951 pin1?
NO
Replace IC951.
YES
Power line of main PCB is short.
3-17
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
POWER
No LED
YES
Is Vcc (DVCC_5V)
supplied to IC206?
NO
Check or replace IC203 block.
YES
Is SPLED_5V is normal?
NO
Check or replace IC206.
YES
Check or replace LED harness cable.
No VFD
YES
VFD_12V is normal?
NO
Check or replace Q202, Q205.
YES
VCC_5V is normal?
NO
Check or replace L105, L211.
YES
VFD_CLK, STB, DO is normal?
NO
Check or replace RT810, RT811, RT812.
YES
Check or replace VFD.
3-18
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
2. MCS PART CHECK
MCS PART CHECK
YES
Check if voltage
of CN201 pin11, 12: 12 V.
NO
Refer to SMPS troubleshooting.
YES
Check if IC202, IC205
have 3.3 VA & 1.2 VA output.
NO
Check and change IC202, IC205.
YES
Check if IC204
have DVCC_3.3V output.
NO
Check and change IC204.
YES
X501: 32.768 kHz, X500: 24 MHz
Check the operation.
YES
OK
3-19
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
3. PWM MODULATION CHECK
PWM MODULATION PART
CHECK
YES
Check CN201
pin11, 12: 12 V.
NO
Refer to
SMPS troubleshooting.
YES
• Check IC601(TAS5548) 3.3 V - pin9, 14, 35, 50.
• Check X601 (12.288 MHz).
YES
Check
X601(12.288 MHz)
operation.
NO
Check X601
(12.288 MHz).
NO
Replace X601(12.288 MHz).
YES
YES
OK
Check IC601 pin21 CLK input.
YES
Check IC501 (MLC3730)
pin U13: RESET, pin10: SDA
pin11: SCL output.
NO
Check line resistor output
RST: R508, SCL: R510,
SDA: R509.
NO
Replace R508, R510, R509.
YES
YES
OK
Check
IC601(TAS5548) input data
pin24 PWM wave.
NO
Check
CD Assy communication
Pin22, 23, 24.
YES
NO
Refer to
CD troubleshooting.
YES
Check IC601
input data.
NO
Check each line resistor output.
YES
OK
Check
PWM modulator output
FL: Pin48(-),49(+). FR: Pin46(-),47(+).
Other output
check.
NO
Check IC601.
YES
OK
NO
Replace IC601.
YES
OK
3-20
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
4. POWER AMP PART CHECK
POWER AMP PART CHECK
YES
Check CN201 pin11, 12: 12 V,
pin3, 4, 5: 58.5 V (47 V, 34.5 V)
NO
Refer to SMPS troubleshooting.
YES
Check IC701
Pin29, 30, 31, 36, 37, 38 input voltage.
YES
Check IC701
pin2: AMP_12V input.
NO
Check each line resistor output voltage.
YES
Check PWM modulator input
IC701 pin5, 6, 14, 15.
YES
Check IC701, IC702
pin27, 28, 32, 35, 39, 40.
YES
Check output line coil.
NO
Replace the coil.
YES
OK
3-21
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
5. TUNER / DAB FUNCTION CHECK
FUNCTION CHECK
YES
Check
IC301 pin27, 28
input.
NO
Check IC302, CN302 (CN5).
YES
Check
IC301 pin18
output data.
NO
Check IC301
Pin8: ADC_3.3V
Pin13, 14: DVCC_3.3V.
NO
Check CN201 pin11, 12: 12 V.
YES
IC501 output data.
NO
Replace IC501.
YES
OK
3-22
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
6. TUNER FUNCTION CHECK
TUNER FUNCTION CHECK
YES
Check tuner IC302 operation.
NO
Check tuner IC(IC302)
voltage (Pin11:AVCC_3.3V).
YES
Check IC301 Pin27, 28.
NO
Check tuner data line R & C.
YES
Refer to function check.
3-23
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
ELECTRICAL TROUBLESHOOTING GUIDE
7. DOUBLE USB FUNCTION
USB FUNCTION
YES
Plug-in USB device.
YES
Display “NO USB”.
YES
Display “READ”.
YES
Display “NO FILE”.
NO
Check USB_5V.
NO
Check CN502.
YES
Check USB_D+, D(R5B69,R5B70,C5B11,C5B14,
ZD505,ZD506).
NO
Check USB jack
(CNT801, CNT802).
YES
Check IC501
(pin U7, U8/ A7, A8).
NO
Replace IC501.
YES
Check USB audio file in USB device
(MP3, WMA file is playable)
3-24
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
WAVEFORMS OF MAJOR CHECK POINT
1. DSP (IC501)
XI
XI
1
3
XO
XO
4
2
Fig 1-1. X501: Crystal of RTC 32.768 MHz
(R5B94 both side)
Fig 1-2. X500: Crystal of system 24 MHz
(MAIN DSP : R5B6, C5B5)
2
3
4
1
3-25
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
2. SDRAM (IC502)
5
6
7
8
Fig 2. SDRAM
8
6
5
7
3-26
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
3. SERVO (IC401)
XI
9
11
XO
10
Fig 3-2. CD-16M
(IC401 pin31)
Fig 3-1. X400: Crystal 16.9344 MHz
9
10
11
3-27
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
4. MOTOR DRIVER (IC400)
16
12
17
13
14
15
Fig 4-1. LO- & LO+ / MOT_OPEN &MOT_CLOSE
for Driving TRAY Motor
(IC400 Pin6, 7, 9, 10)
Fig 4-2. SL- & SL+ for Driving SPINDLE Motor
(IC400 Pin11, 12)
18
19
Fig 4-3. SP- & SP+ for Driving SPINDLE Motor
(IC400 Pin17, 18)
15
13
14
12
17
19
16
18
3-28
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
5. ADC (IC301)
6. USB (CN502)
20
21
23
22
24
Fig 5. ADC I2S
(IC301 Pin15, 16, 17)
Fig 6. USB D+/D(CN502 Pin1, 2, 7, 8)
23
24
21
22
24
23
20
3-29
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
7. BLUETOOTH (CN504)
25
26
27
B
T_TXBT_TX
BT_TX
BT_RX
BT_RX
BT_RST
BT_RST
Fig 7. BT_TX / BT_RX / BT_RST
25
26
27
3-30
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
WIRING DIAGRAM
[ON9 only]
Harness
FAN
FFC
MIC
DAB
Guitar
3pin
FM
MIC
CN462
SD CARD
(Optional)
DIR
8pin
USB2
Heatsink
MIC & Guitar
AMP
DAB
CN303
USB
GUITAR
ADC
USB
CN502
PWM
6pin
USB1
SD CARD
(Optional)
Speaker
CN701
TOP
Control Board
Speaker
Unit
MAIN Board
DSP
8pin
Remote IR
SPK Lighting
CN106
SDRAM
RMC IR
SPK LED
8pin
Speaker
LED
Micom
16pin
UP LED
DN LED
[ON9 only]
CN102
16pin
Power
CN201
12pin
RMC
12pin
BT
CN504
10pin
10pin
TOP Control Board
SMPS
3-31
3-32
BT
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
BLOCK DIAGRAM
ON9/ 7/ 5 : O
RN9/ 7/ 5 : X
MD Block
ANALOG INPUT Block
DAB+FM : ON9/7/5 EU Only (FM BLOCK NA)
OP_SW,CL_SW
(VCC50)
24MHz
P/UP
24MHz
CD_RESB_16M_SUBSYQ
AC,BD,E,F,PD,CD_LD
SERVO
(4ؑ‫)ܖ‬
M
SPDO/SLDO
/ FDO/TRD
DECK
MECHANISM
LOAD± ,SLED± ,
SPIN± ,TR± ,F±
TUNER_SI
CD_LRCK/BCK
, CD_DATA
DAB+ / FM Module
TUNER_CLK/DAT(S0)/RST/CE
CD_DIN_OUT/SD_CMD
CD_BUSY
/SD_DATA0
CD_RW/ SD_DET,
CD_MCK/SD_CLK
FM
TUNER_L/R
SD_DATA1~3
24MHz
TUNER
(FM)
ADC
MOT_MUTE/CLOSE
BT_ADC_DIR_SCL / ADC_DIR_DAT
Guitar
(+3.3V_CD, VCC1.2)
MIC/Guitar
MIC_DATA_IN, ADC_DATA_IN
BT_ADC_DIR_SCL
/ ADC_DIR_DAT
OPTICAL IN
JACK Shielding
DIR
ON9/7 : O
ON5 : X
DIR_INT/RST/CS
D/TEMP
16MB
Flash
8MB
S/Flash
DRM_WEN/CAS/
RAS/SEL/CLK/CKE
M00_15,A00_16
MIC 1
MCS_LRCK/BCK/MCLK
For RCU
DSPI_MCLK/LRCK/B
CK/ADATA
32MB
SDRAM
DAB+/FM
32.768MHz
MOT_OPEN/SD_WP
Motor Drive
DAB+/FM
DAB_L/R
SD Card
IR Receiver
iOS
CP_RESET
Main DSP
PWM_CLK/CP_SCL
,
PWM_DAT/CP_SDA
PWM + AMP
LPF
Block
TW_L
SF_MOSI/MISO
SF_CS/SCK
SF_MOSI/MISO
SF2_CS/SCK
AMP
ON9 series
SE
8Ω (1’’)
TW_R
SE
8Ω (1’’)
Woofer
USB1
1.1
USB2
VFD_STB/CLK/DO RCU
KEY 1/2/3
BTL
BT_PCM_BUFFER
(+3.3VA,5V,+12V)
2.0
BT_TX_RX
TOP BLOCK
D1+/ -, D2 +/ -
6Ω(8’’) x2
MCS_LRCK/BCK
PWM_SCL/DAT
PWM_RST/MUTE
MIX_DATAx_OUT
PWM
AMP
MIX_DATA0/2
VFD
FR_L, TW_L
SE
FR_R, TW_R
SE
ON7 series
4Ω (3’’)
4Ω (3’’)
Woofer
Key (26)
Jog
BTL
MCS_CS/RX/TX
IR Receiver
Micom
( 48Pin)
TW_L
SE
Multi Speaker
Lighting
FAN
AMP
TOP Block
(NEW IC/BLOCK)
TW_R
SE
6Ω (8’’)
ON5 series
8Ω (3’’)
8Ω (3’’)
Woofer
BTL
ON9 Series only
3-33
3-34
3Ω(8’’)
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
CIRCUIT VOLTAGE CHART
1. IC VOLTAGE
RATING SPEC.
2. FAN MOTOR VOLTAGE
RECOMMEND
VOLTAGE(V)
MEASUREMENT
VOLTAGE(V)
IC TC TEMPERATURE
SPEC.
NO.
PARTS SYMBOL
IC FUNCTION
1
IC101
IC, Microcontrollers
VDD : 2.7 ~ 5.5 V
VDD : 3.34 V
VDD : 3.34 V
IC, Microcontrollers
85 °C
2
IC201
DC, DC Converter
VIN : 4.5 ~ 17 V
Vin : 12.10 V
Vin : 12.10 V
Step-Down Converters
125 °C
3
IC202
DC, DC Converter
VIN : 2.5 ~ 5.5 V
Vin : 5.13 V
Vin : 5.13 V
Step-Down Converters
125 °C
4
IC203
DC, DC Converter
VIN : 4.5 ~ 17 V
Vin : 12.10 V
Vin : 12.10 V
Step-Down Converters
125 °C
5
IC204
Limit Switch
VIN : 2.5 V ~ 5 V
VDD : 3.34 V
VDD : 3.34 V
Power-distribution
switch
125 °C
6
IC205
DC, DC Converter
VIN : 2.5 ~ 5.5 V
Vin : 5.13 V
Vin : 5.13 V
Step-Down Converters
125 °C
7
IC206
Limit Switch
VIN : 2.5 ~ 5 V
Vin : 5.13 V
Vin : 5.13 V
Power-distribution
switch
125 °C
8
IC207
Limit Switch
VIN : 2.5 ~ 5 V
Vin : 5.13 V
Vin : 5.13 V
Power-distribution
switch
125 °C
9
IC208
LDO
VIN : ~ 6 V
Vin : 5.13 V
Vin : 5.13 V
1A Ultra Low Dropout Linear
Regulator
125 °C
10
IC301
4ch Audio ADC
AVDD : 3.0 ~ 3.6 V
DVDD : 3.0 ~ 3.6 V
AVDD : 3.36 V
DVDD : 3.3 V
AVDD : 3.36 V
DVDD : 3.3 V
2ch and 4ch Audio ADCs
with Universal Front End Input Mux
125 °C
11
IC302
TUNER
VA : 2.7 ~ 35.5 V
VA : 3.36 V
VA : 3.36 V
TUNER
85 °C
12
IC303
Audio line driver
PVDD : 3 ~ 5.5 V
PVDD : 3.36 V
PVDD : 3.36 V
3VRMS Line driver
85 °C
13
IC304
Sample rate converter
VL : 1.71 ~ 5.25 V
VA : 3.135 ~ 3.465 V
V_REG : 3.135 ~ 3.465 V
VL : 3.3 V
VA : 3.3 V
V_REG : 3.3 V
VL : 3.3 V
VA : 3.3 V
V_REG : 3.3 V
24bit 192 khz sample rate converter
125 °C
14
IC400
Motor Driver
VCC1 : 4.3 ~ 13.2V
VCC2 : 4.3 ~ VCC1
VCC1 : 5.12 V
VCC2 : 5.12 V
VCC1 : 5.12 V
VCC2 : 5.12 V
5-channel BTL Driver
85 °C
15
IC401
Digital servo signal
processing
VDD1 : 2.7 ~ 3.6 V
VDD_CORE : 1.4 ~ 1.65 V
VCC : 3.3 V
VDD_CORE : 1.51 V
VCC : 3.3 V
VDD_CORE : 1.51 V
Servo signal processor
for compact disc player
85 °C
16
IC501
IC, Digital Signal
Processors
Core : 1.1 ~ 1.3 V
VDD IO : 3.0 ~ 3.6 V
VDD33 : 3.34 VA
Core : 1.2 VA
VDD33 : 3.34 VA
Core : 1.2 VA
IC, Digital Signal Processors
85 °C
17
IC502
SDRAM
VDD : 3.0 ~ 3.6 V
VDD : 3.34 V
VDD : 3.34 V
4 M x 4 BANKS x 16 BITS SDRAM
85 °C
18
IC503
Serial Flash Memory
VDD : 3.0 ~ 3.6 V
VDD : 3.34 V
VDD : 3.34 V
SERIAL FLASH MEMORY
85 °C
19
IC504
Serial Flash Memory
VDD : 3.0 ~ 3.6 V
VDD : 3.34 V
VDD : 3.34 V
SERIAL FLASH MEMORY
85 °C
20
IC505
Voltage Detector
VIN : 1.1 ~ 5.5 V
VDD : 3.34 V
VDD : 3.34 V
3-PIN MICROPROCESSOR RESET
CIRCUITS
85 °C
21
IC506
IOP CP Chip
VCC : 1.62 ~ 5.5 V
VCC : 3.36 V
VCC : 3.36 V
Clsas 6 i-Pod 2.0C Ver 2.0C Class
85 °C
22
IC601
PWM IC
DVDD : 3.0 ~ 3.6 V
AVDD : 3.0 ~ 3.6 V
DVDD : 3.34 V
AVDD : 3.36 V
DVDD : 3.34 V
AVDD : 3.36 V
PWM IC
105 °C
23
IC701
AMP IC
PVDD : 12 ~ 62 V
GVDD, VDD : 10.8 ~ 13.2 V
PVDD : 53.3 V
GVDD, VDD : 12 V
PVDD : 53.3 V
GVDD, VDD : 12 V
AMP IC
125 °C
3-35
NO.
CHECK MODE
SPEC.
CHECK RESULT
CHECK METHOD
1
FAN MOTOR
Input Voltage
12 V
11.98 V
Check the Voltage on the
CN462 pin3(FAN_DC), Not
connect FAN Module.(12 V).
2
FAN MOTOR
Operation Voltage
VOL15 : 5.85~7.15 V
VOL16~40 : 9.81~11.99 V
VOL15 : 6.5 V
VOL16~MAX : 10.9 V
During the FAN Operate,
check the Voltage of FAN
Module.
3. SMPS CAPACITOR & ZENER DIODE VOLTAGE
CAPACITOR
NO.
1
2
LOCATION
C903
C904
NO.
1
2
3
4
LOCATION
ZD901, ZD904
ZD902, ZD906
ZD905, ZD912
ZD914
SPEC.
450 V / 270 uF
450 V / 270 uF
SALES AREA
W/W
W/W
ZENER DIODE
3-36
CHECK
33 V
13 V
20 V
33 V
4. MAIN CAPACITOR VOLTAGE
NO.
LOCATION NO.
VALUE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
C101
C122
C125
C214
C271
C2C11
C3A1
C402
C404
C427
C479
C480
C481
C614
C713
C740
C748
C903
C904
C909
C911
C914
C933
C934
C952
C953
C954
CT802
10 uF
100 nF
1 uF
10 uF
220 uF
1 uF
220 uF
100 uF
100 uF
220 uf
22 nF
100 nF
100 uF
100 uF
10 uF
220 nF
1000 uF
270 uF
270 uF
22 uF
47 uF
10 uF
2200 uF
470 uF
1000 uF
1000 uF
1000 uF
47 uF
110 V -20 %
220 V +20 %
(88V, 60Hz) (V)
(288 V, 50Hz) (V)
3.34 V
12.03
12.03
5.12
5.12
12.10
3.35
5.10
3.33
5.12
12.03
10.90
10.90
3.33
12.10
53.30
53.30
119.00
119.00
15.40
22.30
19.40
12.09
12.08
53.70
53.70
53.70
5.10
3.34 V
12.03
12.03
5.12
5.12
12.10
3.35
5.10
3.33
5.12
12.03
10.90
10.90
3.33
12.10
53.30
53.30
404.00
404.00
15.40
22.30
19.40
12.09
12.08
53.70
53.70
53.70
5.10
DESCRIPTION
DVCC_3.3V
VFD_12V
VFD_12V
+5.1V
USB_5V
AMP_12V
AVCC_3.3V
DVCC_5V
DVCC_3.3V
M_5V
+12V
FAN_DC
FAN_DC
DVCC_3.3V
AMP_12V
PVDD
PVDD
1st Regulation Cap
1st Regulation Cap
IC901 Vcc
IC911 Vcc_1
IC911 Vcc_2
12VA
12VA
PVDD
PVDD
PVDD
VCC_5V
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
5. CONNECTOR VOLTAGE
NO.
1
2
3
4
CON NO.
CN102
CN103
CN106
CN201
CON
NAME
MAIN

TOP
MAIN

SD CARD
MAIN

MULTI
LIGHTING
MAIN

SMPS
PIN NO.
PIN MANE
1
2
VOLTAGE(V)
CON NO.
PIN MANE
12.10
1
0.00
2
5.10
5.10
3
DV_5.0V
5.10
5.10
DV_3.3V
3.34
3.34
6
VFD_CLK
3.33
3.33
7
VFD_STB
3.33
3.33
8
VFD_DAT
3.33
3.33
9
DGND
0.00
0.00
10
DGND
0.00
11
KEY3
3.33
12
KEY2
13
14
15
Vout
VF_12V
12.10
DGND
0.00
3
DV_5.0V
4
5
NO.
5
CON NO.
CON
NAME
PIN NO.
Vin
CN303
MAIN

DAB
MODULE
VOLTAGE(V)
Vin
Vout
TUNER_L
-
-
GND
-
-
TUNER_R
-
-
4
GND
-
-
5
DAB CE
-
-
6
DAB CLK
-
-
7
DAB MOSI
-
-
8
DAB MISO
-
-
9
TUNER RST
-
-
0.00
10
GND
-
-
3.33
11
GND
-
-
3.33
3.33
12
3.3V
3.36
3.36
KEY1
3.33
3.33
1
GND
-
-
JOG_B
3.33
3.33
2
NC
-
-
JOG_A
3.33
3.33
3
FAN_DC
10.90
10.90
16
DGND
0.00
0.00
1
D2+
3.30
3.30
1
CD/DAT3
-
-
2
D2-
0.00
0.00
2
CMD
-
-
3
VSS1
-
-
4
VDD
3.34
3.34
5
CLK
-
-
6
VSS2
-
-
7
DAT0
-
-
8
DAT1
-
-
9
DAT2
-
-
10
DETECT_
CONTACT
-
-
11
COM2
-
-
12
WRITE_PROTECT_CONTACT
-
-
13
GND
-
-
1
SPKLED_B
-
-
2
SPKLED_G
-
-
3
SPKLED_R
-
-
4
LGND
-
-
5
LGND
-
-
6
DGND
-
-
7
3.3VA
3.34
3.34
8
RMC
-
-
1
12V
12.10
12.10
2
12V
12.10
12.10
3
DGND
-
-
4
P_CTRL
-
-
5
DGND
-
-
6
DGND
-
-
7
DGND
-
-
8
PVDD
53.30
53.30
9
PVDD
53.30
53.30
10
PVDD
53.30
53.30
11
DGND
-
-
12
PVDD CTRL
-
-
CNT804
6
7
CN462
CN502
MAIN

FAN
MAIN

TOP
(USB)
SD
CARD
8
CN504
CNS301
CNS302
9
CN701
MAIN

BT
Moudle
MAIN

SPK
3
DGND
0.00
0.00
4
USB_5V
0.00
0.00
5
USB_5V
0.00
0.00
6
DGND
5.09
5.09
7
D1+
0.00
0.00
8
D1-
0.01
0.01
1
SDA
0.12
0.12
2
SCL
3.33
3.33
3
GND
0.00
0.00
4
TXD
3.33
3.33
5
GND
0.00
0.00
6
RXD
3.33
3.33
7
RTS
1.49
1.49
8
CTS
1.51
1.51
9
RESET
3.33
3.33
10
VDD
3.33
3.33
1
SW+
2
SW-
-
3
FL+
-
4
FL-
-
5
FR+
-
6
FR-
-
CON NO.
DAB
MODULE
FAN
CNT803
BT
Module
-
SPK
CN901
3-37
3-38
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
Q913
Q912
R913
R912
R973
FB903
FB904
C917
R919
C915
IC911
CY901
C914
W932
W923
R967
ZD904
R951
R925
W907
W906
W913
R910
C923
R921
W910
R956
C956
R952
R953
R971
R972
TP911
R961
R954
W924
ZD906
R948
R968
ZD932
R955
TP914
W921
IC952
Q950
R970
W914
TP913
R962
IC951
TP912
PC904
W918
PC903
TP910
ZD933 C935
TP905
ZD905
Q902
HS952
T903 T 9 0 4
HS955
C951
R966
HS901
R969
TP906
D913
R949
TP915
D905
ZD912
TP908
TP909
R922
C920
3-40
TP907
BD901
W909
R914
R947
FB902
D951
C931
C913
D911
W905
OTW3
OTW4
OTW2
OTW1
C918
TH952
C912
C952
W925
R917
TH951
R920
C916
C919
R926
W915
W917
Q901
L F9 0 2
3-39
R911
C955
R916
C950
R959
R957
C953
TP918
R944
R942
W901
R941
W916
R943
W929
TP917
R965
C922
W926
W903
R924
W922
ZD902
R946
W908
W912
Q911
R964
W920
C937
W911
C954
IC941
R945
PC901
L931
C933
C910
R906
D903
FH902
W927
TP903
C909
C961
1 1
C934
F901
R908
W902
9
TP904
D922
P
N
9
IC901
7
D921
0
T901
5
D906
W931
1
FB901
R
B K)
(B
D901
C906
3
D906
C904
JIG
C905
R904
CY902
R905
FH901
D902
R907
L )
B H
(W
D904
C900
W904
R934
PC902
ZD903
ZD901
CM901
R909
ZD907
C908
VR901
1,2:12VA 3:GND
4:P-CTRL 5,6,7:GND
8,9,10:PVDD 11:GND
12:V-CTRL
LF903
R901
R902
TP901
R958
W930
R963
R915
C921
Q951
W928
CY900
TP916
LF901
C903
R903
C911
TP902
R960
LF904
W919
CM902
TH901
TH902
TH903
1
0
9
C
JIG
#4
1
#8
OTW904
OTW908
#3
CN901
#7
OTW903
OTW907
#2
#6
OTW909
OTW902
OTW906
#1
#5
OTW901
OTW905
NOTE) Warning
Parts that are critical with respect to risk
of fire or electrical shock.
(TOP VIEW)
(BOTTOM VIEW)
1. SMPS P.C.BOARD DIAGRAM
PRINTED CIRCUIT BOARD DIAGRAMS
2. MAIN P.C.BOARD DIAGRAM
R369
C479
R358
R355
Q487
R465
Q706
C348 C349
R760
R474
R475
R473
C780
R749
C755
C781
C775
C779
R712 C721
L707
C713
C739
C615
C740
C736
C770
D703
R730
R746
R777
R748
C758
L706
C735
IC701
R621
R745
C769
D702
C731
R250
R247
R617
IC601
C613
C5E2
C753
C766
X601
C614
C612
RA601
R624
R625
R702
C705
R744 R741
R743 R740
R742 R739
TP158
C182
Q103
Q106
C264 C254 C256
C216
C201
C202
L201
L211
CN106
C185
TP156
TP154
TP153
L108
C183
TP152
R731
R732
CN504
R206
R209
C208
R241
R204
R202
C748
CS748
CM748
D202
C253
C280
L202
L110
C184
C180
C263
IC203
L210
C213
IC201
R245
ZD202
R244
C229
L203
L212
C274
C277
C2D2
C2C6
C284
R243
C205
R218
R207
C230
R242
C233
C204
R222
L109
C288
IC202
R208
ZD205
L206
C232
C218
R128
R127
R102
C5E6
C222
C2B5
R210
R230
C211
C287
C2D1
R213
R220
C252
C251
C282
C215
C 2 8 1R 2 3 1
C212
C203
D204
C221
C226
C5B25
Q101 Q102
Q104 Q105
C181
R5D5
R5D8
IC205
R221
L5B8
TP157
LG07
TP155
R203
C2C12
C231
C214
C2C5
R237
R238
ZD506
R729
C732
IC506
R5B33
R5B34
R5B52
R5B36
R5B48
R5B63
R505
R503
C765
R240 R239
3-41
3-42
C510
C509
L505
L506
R5D2
L507
R5D1
C513 C515 C524 C532 C514 C522
L508
L502
R246
C512
L310
C561
C286
C279
C276
ZD204
C508
C207
C261
IC208
C273
CN101
R233
ZD203
R214
C209
CN201
C246
C297
C177
R112
R111
IC204
C106 C105
R116
2019.12.13
EAX69094501 VER1.4
R776
R747
C757
R736 R733
R737 R734
R738 R735
C742
R628
R629
R710
R723
R726
P_DAT
P_SCL
R524 R612
R5B6
C5B5 C5B2
X500
C5B34
7
4
3
2
1
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
R5B1
C752
L205
C2A6
ON9/7/5 Main BOARD
FR4-2L 1.6T 220X146 (220X125)
R626
R627
M_SCL
C108
R129
Q202
C104
15
C102
C101
C103
C2C1
R601
C5E3
C130 C131
R103 R104
C217
R109
R101
RA102
CN701
R764
D701
R750
C756
R248
C776
C778
C388
L308
R472
R471
R757
R758
IC303
C381
C391
C480
C741
R611
FL500
R122
R147
L101
C243
C124
C192
C117
TP145 TP143
TP144
10
TP147
C481
Q709
R329
C353 C351 R328 R5E9
R712A
M_DATR602
TP151
TP148
TP150
C390
ZD702
MES
SOLDERING
R5D7
C237
Q205
C605 R613 C601 R616
R5B95
C5B23
C5B24
R508
R5D10
R596
R5B5
C5B4
ZD501
R5B45
R5B17 R5B24 R5B21
R5B15
R5B28
R5B26
R5B29
R5B32
R5B38 R5B30
C407
C248
C122
C123
5
CN102
L329
C378
R346
C602
C604 C603
R615 R614
C607 C606
R5B94
R5B4
R5B47 DFT_TX
R5B9 R5B7
R5B37
R5B8
R5B10
R5B11 R5B22
R5B42 R5B43
R5B44
C107
C405
TP146
L328
C383
R378
R302
C326
C271
C5B21
R5B115
R5B98 R5B107 C5B60
Q207
C2B3
C5B18
X501
IC501
CN401
L113
CN462
C2C11
TP521
R219
R504
R501
C5B33
8 10 12 14 16
9 11 13 15 17
RA503
RA501
TP519
A
R5B53 R5B51 R5B106
R414
R412
R411
R410 R413
C427
L204
L105
R380 C336
L306
R372
C373
L326
C371
C396
C397
R335
Q208
5
ZD505
RX
C2B9
C411
C410
C428
C440
TP142 TP140 TP139 TP138
R5B99
R5B100
SF_MISO
SF_CS
RA504
R5B64
R5B65
R5B61
R5B60
R5B56
R416
R417
TP149
C5B41
RA502
R5B72 R5B73
R5B75 R5B74
R5B69
C5B11 C5B14
CN501
TP520
C5B39
6
C424
C436
C539
C125
R761
TP468
TP467
R156
R462
R762
R330
C359
L112
B
C439
R5B70
C5B43
R5B102
R5B104
C5E7
C5B26
C5B30
C5B44
IC504
C412 C418A
C413
C438
C443
C441
SF_MOSI
L5B3
ZD400
L106
LG06
L307
C329
C328 IC302
L303
C361
C3A2
R251
5
C418
C437
R422 R423 C445
TP523
TP522
SF_SCK
C431
C433
R334
C367
D103
C194 R155 D102
C195 R154 D101
R5E15
R5E16
CN502
R752
R756
R348
L313
C320 C316
C319 C315
R755
C788
IC304
C3A1
L5B9
C414
C419
X400
C444
C430
C387
C376
R331
R311
R310
Q485
R359
R367
R366
R365
C393 R362
R363
R360 R361
R252
C423
L406
L403
R382
C386
C385
R371
C384
C399
C337
B
C417
C422
JK302
L312
R5B114
R5B113
10
C363
C362
C402
C421
R370
TP518
C416
C429
C394
L327
JK301
CN303
C395
R368
B
15
C404
X301
R5E10
R5E11
C191
R5E12
R5E13
R5E14
20
C409
C193
R151
R150
C188 R153
C190 R152
C189
R148
D104
10
C187 R149
C432
9
C368
CN103
R379
R381
C380
C375 C389 C377 C379
C332
C335
13
C372
R301
R327
R317
C340
11
CN400
L325
RA302
LG04
C374
R373
RG06
L318
C342
R383
C398
12
C343
D301
JK303
CN302
(TOP VIEW)
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
MAIN P.C.BOARD DIAGRAM
(BOTTOM VIEW)
CN302
JK302
JK301
ANT
JK303
TG
TP29
TP17
TCL
C334
TSD
C331
C333
TP31
TEN
TRST
C355
TP33
TP22
TP27
TP23
C420
R415
C2C3
R403
R404
R406
R407
C425
C434
C446
IC401
C447
C426
R418
TP424 TP422
L5B2
C5B8
R5E8
R582
R5B16
R5B19
R5B14
R5B20
R5B12
R5B2
IC400
DFT_RX
R5B46
R5B3
R5B39 C556 C504
C415
TP418
C114
C2C4
RA106
C112
R115
R125
TP136
C113
TP103
TP102
TP104
TP101
C2A5
R126
TP123
LG09
C5B1
RA103
C138
C137
C136
ON9/7/5 Main BOARD
FR4-2L 1.6T 220X146 (220X125)
2019.12.13
EAX69094501 VER1.4
CN102
TP137 TP125 TP124 TP122 TP121 TP117 TP115 TP109
TP421
TP105
TP423 TP425
TP420
R108
R120
R158
TP505
C2B6
3-44
TP407
TP408
C401
C403
C238
C542
TP427
R419
C5B7
R212
3-43
TP410
TP414
C2C2
C552
Q504
TCK
TDO
R5B66 R5B84
R5B81
R5B23
R5B79
R5B77
R5B76
R513
R110
TP502
TP428
TP426
C435
TP417
ZD502
TP409
R400
C408 R409
C406
Q503
R5E17
R593
R594
R598
C540
R5B105 R531
C5B58
C5B55
GND
R119
CN201
TP510
ZD504
C5B31
C5B51
C5B15 C5B32
R5B27
R5B31
R5B110
R5B13
R5B35
RB117
R5B18
C250
TP201
R405
TP429
RST
C543
VDD
TDI
TP419
C206
TP503
BTGND TP501
TP508
R402
RTCK
IC101
TP506 TP509
TP504
TMS
C400 TP400
TP430
C548
C546
NTRST
C239
C2C9
R205
R201
R225
R226
TP203 TP202
L400
R215
TP207 TP206
TP204
R520
C541
C2C8
C259
TP205
C500
R5B80
R5B78
R5B86
C5B53
R5D6
C224
C219
TP416
TP415
TP412
C501
C5E4
C2C7
C258
L5B12
IC503
C5B38
C245
C5B17
C5B56
C5B52
R5D16
R5D15
R5D18
R5B25 C5B40
C5B42
C5B46
C241
C240
C262
TP401
C298
C5E5
C2C10
C255
C5B59
R5B96
R5B97
C5B35
C5B37
R5D12
C5B49
C5B50
C2A7
ZD201
R216
TP10
C5B57
C5B54
C5B48
R5B88
R5B62
R5D4
R5B101
R5D3
C5B36
C2B4
R232
R234 C223
C227
TP11
TP517
C5B29
L5B10
C278
C275
C269
D203
R506
R5B71
R5B67
L5B4
R B 1 0R55 B 1 1 1
R597
R5D17
R249
IC206
C178
L107
R229
R228
C5B16
C5B12
C5B13
C618
C617
C179
C186
TP13
R5B83
R510
R5B103
L5B5
R5B68
R5D11
R5B58
C5B19
L701
TP15
TP12
C5B20
C725
C235
R5D13 R502 R509
CM748
CS748
C748
C268
C267
C5B22
L5B6
R511
R512
TP16
C5B45
C5B47
C611
R5B112 R5B116
L5B11
TP406
TP405
TP404
TP403
TP402
C300
IC502
C2B1
L5B7
C753
TP14
R519
R619
R620
C382
C234
R751
R5D14 R5B55 R5D19
R5D9
R5B50
R5D20
IC505
C610
TP411
Q400
TP507
R521
C5B3
C609
C303
SF2_CS
C608
PWM_FR-
CN701
R775
R759
8
C304
TP512
D201
TP413
C321
C299
C2B2
ZD701
C708
L706
PWM_FLC616
C707
FL-
7
TP515
C225
TP310 TP302
TP304
TP312
R709
C706
FR+
U201
L401
C322
TP6
TP7
TP9
TP34
TP8
TP4
TP3
C220
TP311
C703
R727
R725
C723
C752
6
C2A8
4
TP301
ZD503
C2A3
C2A4
C718
R307
R306
R308
R313 R312
R318
TP313
R309
SW-
R384
R408
IC209
C310
TP511
C228
R701
3
C270
C311
C312
C236
L703
2
5
TP516
L707
1
LG01
R401
L402
R385
C327
TP513
TP32
TPJIG
C536
ZD507
R223
C309
L301
R305
C308
C346
L315
C272
L513
C534
R217
C537
R235
C324
L309
IC207
C307
R387
R386
L213
IC301
L320
L324
R388
TP30
TP1
C318
C317
C392
C314
C313
R770
R466
R470
R469
R468
R467
C301 C305
C302 C306
L311
FL+
TP5
TP18
TP26
L304
C360
TP20
TP24
C330
C354
C352
C2A9
TP466
SW+
C365 C364 C370 C369 C366
C356
C358
R768
Q710
R769
TP465
TP19
TP21
C347
Q708
R774
R773
C350
R771
Q488
R464
R157
R463
C789
R772
TP25
C344
R754
Q486
TP28
C357
TP116
TP110
TP107
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
3. TOP KEY P.C.BOARD DIAGRAM
(TOP VIEW)
3-45
3-46
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
3-48
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.
TP806
CNT803
TP803
TP804
3
4
8
RCT801
VFD801
CNT802
CNT801
W104
W103
CT817
RT816
CT820
W114
W251
VFD_12V
TP809
TP810
W203
W108
W242
W232
W107
W233
W264
W123
W102
W106
W176
CT818
CT819
TP816
W225
W186
CNT804
W105
W185
TP813
W227
TP805
TP807
TP801
TP815
TP814
RMC
VCC_5V
CT816
W229
W228
W218
W112
RT806
RT807
RT803
RT801
W117
W175
CT815
VFD_CLK
W120
TP812 RT802
RT805
RT804
CT826
W204
3.3VA
VFD_STB
VFD_D0
KEY3
W110
KEY2
KEY1
JOG_B
CT801
CT805
ZDT801
JOG_A
TP819
W215
DT802
DT801
CT810
RT812
W118
RT843
RT830
W115
CT812
W113
W213
W181
RT811
RT810
CT804
CT802
W122
CT808
CT832
W270
W249
W252
RT842
CT842
CT813
TP818
ZDT802
ZDT803
RT808
RT813
CT811
CT809
CT807
DT803
SWT808
QT801
W116
TP808
W111
2
1
RT815
7
TP820
TP802
CT841
TP811
CT825
RT809
CT803
SWT811
RT829
RT828
CT806
SWT810
SWT809
RT851
W223
6
5
3-47
ON9/7/5 TOP KEY
EAX69075201 VER 1.4
2019.12.16
PCB SIZE:280X185.5 (175.5)
FR-1[1.6T]
SWT825
SWT826
DT804
W217
SWT824
W261
RT838
RT837
W216
RT850
W219
SWT820
SWT819
RT827
RT841
QT802
W194
RT836
SWT817
CT834
SWT818
W202
SWT805
W214
W177
RT824
SWT804
W221
RT826
RT835
CT830
CT833
W206
W209
VRT801
W268
SWT807
SWT806
SWT816
RT825
RT823
SWT822
SWT823
W212
RT840
CT831
W210
SWT803
RT822
SWT802
RT834
W197
RT821
W271
SWT815
RT833
RT832
RT831
W101
W205
W184
SWT814
CT843
RT839
S WT 8 1 3
W180
CT844
S WT 8 1 2
RT820
W226
SWT801
SWT821
W109
(BOTTOM VIEW)
TOP KEY P.C.BOARD DIAGRAM
4. LIGHTING LED P.C.BOARD DIAGRAM
(TOP VIEW)
(BOTTOM VIEW)
2019.11.07
EAX69075301
VER1.2
RS305
RCS301
RS307
TPS310
CS301
1
CNS302
CS303
CS302
TPS303
LEDS01
TPS311
ZDS301
CS308
TPS304
TPS305
RN9/7/5
CNS301
CS306
CS307
DS301
TPS307
TPS301
TPS302
RS303
RS302
RS301
RS304
CS305
ON9/7/5 Lighting LED BOARD
FR4-2L 1.6T (31X24)
TPS306
5. DAB MODULE P.C.BOARD DIAGRAM
(TOP VIEW)
(BOTTOM VIEW)
CN1
PCB SIZE
:32 X 52.5
CN1
TP2
SCAN1
L7
C15
C01
INTB
IC01
IC02
R38
R04
C19
C18
C16
C24 R14
L6
R08
R06
R02
C17
R07
C14
XD1
D01
L1
C05
C07
C04
C28
C32
C03
R11
C25
BCK
R10
R09
L21
C09
ADATA C06
R13
R23
R22
L2
L4
C08
C10
C11 C12 C13
LRCK
R01
L3
R12
C23
C22
C20
R16
IC03
C26
R17
C38
R15
EAX69077001 Ver1.3 FR4-4L 1.6T 19.12.13
RF_IN
C02
L8
L5
C21
C35
C36
RST
C37
MOSI CS
SHIELD CAN : 28X30
C34
C39 C33 C31 C30
C27
CN3
3.3V GND
3-49
3-50
MISO CLK
A_R A_L
Copyright © 2020 LG Electronics Inc. All rights reserved.
Only for training and service purposes.