LG SR906SB Service manual

MODEL: SR906SB (SR906SB, SH96SB-S/ F/ C, SH95TA-W)SERVICE MANUAL

Internal Use Only

Website http://biz.lgservice.com

5.1ch SURROUND COMPACT
RECEIVER SYSTEM

SERVICE MANUAL

MODEL: SR906SB

CAUTION

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

JUNE, 2011AFN33798528 : ON/P

(SR906SB, SH96SB-S/ F/ C, SH95TA-W)

CONTENTS

SECTION 1 ........ SUMMARY

SECTION 2 ........ ELECTRICAL

SECTION 3 ........ CABINET & MAIN CHASSIS

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

1-1

SECTION 1

SUMMARY

CONTENTS

PRODUCT SAFETY SERVICING GUIDELINES FOR AV RECEIVER SYSTEM PRODUCTS................ 1-3

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

• GENERAL SERVICING PRECAUTIONS

• INSULATION CHECKING PRODEDURE

• ELECTROSTATICALLY SENSITIVE (ES) DEVICES

SERVICE INFORMATION FOR EEPROM (MICOM) .................................................................................... 1-5

VERIFICATION PROGRAM VERSION AND MICOM OPTION ................................................................... 1-6

FIRMWARE UPDATE ...................................................................................................................................... 1-7

SPECIFICATIONS ............................................................................................................................................ 1-8

1-2

PRODUCT SAFETY SERVICING GUIDELINES

FOR AV RECEIVER SYSTEM 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 cus-

tomized 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:

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.

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.

1-3

SERVICING PRECAUTIONS

CAUTION: Before servicing the AV RECEIVER SYSTEM 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 publications, always follow the safety pre­cautions.
Remember Safety First :

General Servicing Precautions

1. Always unplug the AV RECEIVER SYSTEM 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 electro-

lytic capacitor.

Caution : A wrong part substitution or incorrect polar-

ity installation of electrolytic capacitors may result in an
explosion hazard.

2. Do not spray chemicals on or near this AV RECEIVER
SYSTEM or any of its assemblies.

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.

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
whitch instruments covered by this service manual might be
equipped.

5. Do not apply AC power to this AV RECEIVER SYSTEM
and / or any of its electrical assemblies unless all solidstate
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.

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 cir-

cuit, 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

SERVICE INFORMATION FOR EEPROM (MICOM)

1. ENTER THE MICOM OPTION CHANGING MODE

1)

At any function, press front ‘STOP’ button and remote control ‘2’ key for 5 seconds. Enter the MICOM option setting menu.

2. ADJUST MICOM OPTION USING REMOTE CONTROL DIRECTION KEY

1) Using up / down direction key (preset +, -), change option value.

2) Using left / right direction key (tunning +, -), select next option.

DETECT NEW EEPROM
(OPTION EDIT SCREEN)

NAME HEX

OP0
OP1
OP2
OP3
OP4
OP5

09
BE
20
C6
00
C0

3. COMPLETE OPTION CHANGING.

1) After entering option code, press ‘ENTER’ key. You can confi rm ‘WRITE OK’.

2) Next, press front ‘STOP’ button and remote control ‘2’ key. ‘E2P CLR’ display on VFD.
Finish option code changing.

1-5

VERIFICATION PROGRAM VERSION AND MICOM OPTION

1. ENTER THE VERIFICATION MODE

1) At any function, press front ‘STOP’ button and remote control ‘PLAY’ key for 5 seconds.
Enter the Program Version and MICOM Option code verifi cation mode.

2) Using left/right key, you can confi rm program version and MICOM option.

MICOM Version

DSP Version

2. RETURN TO FUNCTION

1) After checking, press remote control ‘PLAY’ key for 5 seconds.
Return to function that before you’re set.

MCS Version

MICOM option

1-6

FIRMWARE UPDATE

1. COPY AN UPDATE FILE TO USB (USB OR CD-ROM)

Update File Name: MICOM_SR906_1XXXXXX.hex

MCS_SR906_1XXXXXX.bin
DSP_SR906_1XXXXXX.hex

1) An update fi le have to be copied onto the root of fi le system.
And fi les are all erased except update fi le.

2. UPDATE FIRMWARE

1) Insert USB which has an update fi le.

2) VFD responds to update event.

3) VFD is shown as below.

Front Panel contents:

UPGRADE

3. AFTER UPDATE COMPLETE

1) Power off / on automatically after update complete.

2) Tray will be closed.

1-7

SPECIFICATIONS

• GENERAL

Power requirements Refer to main label on the rear panel.
Power consumption Refer to main label on the rear panel.
Dimensions (W x H x D) Approx. 430 x 60 x 243.5 mm (16.9 x 2.4 x 9.2 inches)
Net Weight (Approx.) 2.9 kg (6.4 lbs)
Operating temperature 5 °C to 35 °C (41 °F to 95 °F)
Operating humidity 5 % to 90 %
Bus Power Supply (USB) DC 5 V 1 mA

• INPUTS/OUTPUTS

HDMI IN/OUT (video/audio) 19 pin (Type A, HDMI™ Connector)
ANALOG AUDIO IN 2.0 Vrms (1 kHz, 0 dB), 600 Ω, RCA jack (L, R) x 1
DIGITAL IN (OPTICAL) 3 V (p-p), Optical jack x 2
DIGITAL IN (COAXIAL) 3 V (p-p), Coaxial jack x 1
PORT. IN 0.5 Vrms ( ø 3.5 mm stereo jack)

• TUNER

FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz
AM Tuning Range 520 to 1,710 kHz

• AMPLIFIER

Power output (4 Ω/ 3 Ω), (RMS), THD 10 %
Total 1100 W
Front 180 W x 2
Center 180 W
Rear 180 W x 2
Sub-Woofer 200 W (Passive)

1-8

• SPEAKERS

Front speaker (Left/ Right)

Type 2 Way 2 speaker
Impedance Rated 4 Ω
Input Power 180 W
Max. Input power 360 W
Net Dimensions (W x H x D) 94 x 211 x 83 mm (3.7 x 8.3 x 3.3 inches)
Net Weight 0.7 kg (1.5 lbs)

Rear speaker (Left/ Right)

Type 1 Way 1 speaker
Impedance Rated 4 Ω
Input Power 180 W
Max. Input power 360 W
Net Dimensions (W x H x D) 94 x 182 x 83 mm (3.7 x 7.2 x 3.3 inches)
Net Weight 0.61 kg (1.34 lbs)

Center speaker

Type 2 Way 3 speaker
Impedance Rated 4 Ω
Input Power 180 W
Max. Input power 360 W
Net Dimensions (W x H x D) 327 x 99 x 76 mm (12.9 x 3.9 x 3.0 inches)
Net Weight 1.21 kg (2.67 lbs)

Subwoofer

Type 1 Way 1 speaker
Impedance Rated 3 Ω
Input Power 200 W
Max. Input power 400 W
Net Dimensions (W x H x D) 190 x 385 x 318 mm (7.5 x 15.2 x 12.5 inches)
Net Weight 5 kg (11 lbs)

1-9

MEMO

1-10

SECTION 2

ELECTRICAL

CONTENTS

ONE PONIT REPAIR GUIDE .......................................................................................................................... 2-2

1. NO POWER PROBLEM ......................................................................................................................... 2-2

2. AMP POWER PROBLEM ....................................................................................................................... 2-4

3. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR

“WELCOME” ON FRONT PANEL .......................................................................................................... 2-5

4. BAD HDMI VIDEO / AUDIO OUTPUT .................................................................................................... 2-6

5. BAD HDMI VIDEO / AUDIO INPUT ........................................................................................................ 2-7

6. BAD USB FUNCTION ............................................................................................................................. 2-8

7. NO SPEAKER OUTPUT ......................................................................................................................... 2-9

ELECTRICAL TROUBLESHOOTING GUIDE ............................................................................................. 2-12

1. POWER SUPPLY ON SMPS BOARD .................................................................................................. 2-12

2. POWER SUPPLY ON MAIN BOARD ................................................................................................... 2-15

3. POWER SUPPLY ON AMP BOARD .................................................................................................... 2-16

4. POWER SUPPLY ON FRONT BOARD ............................................................................................... 2-17

5. SYSTEM PART ..................................................................................................................................... 2-18

6. NO AUDIO OUTPUT ............................................................................................................................ 2-19

7. NO USB FUNCTION ............................................................................................................................. 2-21

8. NO HDMI OUTPUT ............................................................................................................................... 2-22

9. NO HDMI INPUT ................................................................................................................................... 2-23

WAVEFORMS ................................................................................................................................................. 2-24

1. SYSTEM PART-1 (MICOM) .................................................................................................................. 2-24

2. SYSTEM PART-2 (HDMI) ..................................................................................................................... 2-25

3. AUDIO PART-1 (DSP) .......................................................................................................................... 2-26

4. AUDIO PART-2 (DIR) ........................................................................................................................... 2-27

5. AUDIO PART-3 (MCS) ......................................................................................................................... 2-28

6. AUDIO PART-4 (PWM) ......................................................................................................................... 2-29

WIRING DIAGRAM ........................................................................................................................................ 2-31

BLOCK DIAGRAM ......................................................................................................................................... 2-33

CIRCUIT DIAGRAMS .................................................................................................................................... 2-35

1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 2-35

2. AUDIO MICOM CIRCUIT DIAGRAM .................................................................................................... 2-37

3. AUDIO DSP CIRCUIT DIAGRAM ......................................................................................................... 2-39

4. HDMI CIRCUIT DIAGRAM.................................................................................................................... 2-41

5. ADC / DIR CIRCUIT DIAGRAM ............................................................................................................ 2-43

6. MCS CIRCUIT DIAGRAM ..................................................................................................................... 2-45

7. PWM CIRCUIT DIAGRAM .................................................................................................................... 2-47

8. AMP CIRCUIT DIAGRAM ..................................................................................................................... 2-49

9. FRONT CIRCUIT DIAGRAM ................................................................................................................ 2-51

10. VOLUME CIRCUIT DIAGRAM .............................................................................................................. 2-53

CIRCUIT VOLTAGE CHART ........................................................................................................................ 2-55

PRINTED CIRCUIT BOARD DIAGRAMS .................................................................................................... 2-57

1. MAIN P. C. BOARD .............................................................................................................................. 2-57

2. SMPS P. C. BOARD ............................................................................................................................. 2-59

3. AMP P. C. BOARD ............................................................................................................................... 2-61

4. FRONT P. C. BOARD ........................................................................................................................... 2-63

5. VOLUME P. C. BOARD ........................................................................................................................ 2-65

2-1

ONE POINT REPAIR GUIDE

1. NO POWER PROBLEM

No power problem occurs when you power on the unit.

1-1. FUSE & BRIDGE DIODE
1-1-1. Solution

Replace F901, BD901 on SMPS board.

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

1) Look at the physical of fuse F901.

2) Check the bridge diode BD901.

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

< Fuse, F901 >

Can look at physical condition

< SMPS board top view >

2-2

ONE POINT REPAIR GUIDE

No power problem occurs when you power on the unit.

1-2. VFD, 12 V, 6 VA, 3.7 VA

1-2-1. Solution

Replace D927, D926, D921, D922, D923, D925, IC901, IC951.

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

Case 1) FLD Abnormal: Check D927, D926 and replace it.
Case 2) 6 VA Abnormal: Check D921 and replace it.
Case 3) 12 VA Abnormal: Check D925, IC951 and replace it.
Case 4) 3.7 VA Abnormal: Check D922, D923 and replace it.
Case 5) All Voltage Abnormal: Check IC901 and replace it.

Case 1

Case 2

Case 5

Case 4

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

Case 5

Case 3

Case 3

Case 4

Case 2

Case 1

< SMPS board bottom view >

2-3

ONE POINT REPAIR GUIDE

2. AMP POWER PROBLEM

AMP VCC doesn’t work.

2-1. ABNORMAL SOUND

2-1-1. Solution

Refer to “How to troubleshoot (Countermeasure)”.

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

Case 1) 36 V Abnormal: Replace PC902 or PC903 on SMPS board.
Case 2) 36 V Abnormal: Replace IC902/ Q901 or D928 on SMPS board.

Case 1

Case 2

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

Case 1

Case 2

Case 1

Case 2

< SMPS board bottom view >

2-4

ONE POINT REPAIR GUIDE

3. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR
“WELCOME” ON FRONT PANEL

When you turn on your set, it will blank / no message or “WELCOME” display on front panel, and it

will not boot-up.

3-1. D101 (NO 3.3 VA)

3-1-1. Solution

Replace D102 on MAIN board.

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

1) Please check 3.7 VA(yellow signal).

2) If 3.7 VA is abnormal, please check SMPS board.

3) If 3.7 VA is OK, but 3.3 VA is abnormal, replace D102.

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

A:3.7VA

B:3.3VA

D102

< MAIN board bottom view >

2-5

ONE POINT REPAIR GUIDE

4. BAD HDMI VIDEO / AUDIO OUTPUT

When unit is connected to HDMI TV using HDMI cable, picture shows bad color, no output or mixed

color on the screen. But component output is OK.

4-1. HDMI JACK (JK802)

4-1-1. Solution

Replace JK802 (HDMI Jack).

4-1-2. How to troubleshoot (Countermeasure)

1) Check JK802 pin soldering.

2) If there is short soldering on pin JK802, re-soldering pin JK802.

3) If problem still occurs, check L808 ~ L811.

4) Check X800 waveform. If it is abnormal signal, replace X800.

5) If issue still NG, replace IC800.

4-1-3. Service hint (Any picture / Remark)

JK802

IC800

X800

< MAIN board top view >

2-6

ONE POINT REPAIR GUIDE

5. BAD HDMI VIDEO / AUDIO INPUT

When unit is connected to HDMI in(1 or 2, 3) using HDMI cable, picture shows bad color, no output

or mixed color on the screen.

5-1. HDMI JACK (JK801 OR JK800, JK803)

5-1-1. Solution

Replace JK801 or JK800, JK803 (HDMI Jack).

5-1-2. How to troubleshoot (Countermeasure)

1) Check JK801 or JK800, JK803 pin soldering.

2) If there is short soldering on pin JK801 or JK800, JK803 re-soldering pin JK801 or JK800, JK803.

3) If problem still occurs, check R803 ~ R826:

If issue still NG, replace IC800.

5-1-3. Service hint (Any picture / Remark)

JK801 JK800

IC800

X800

< MAIN board top view >

JK803

2-7

ONE POINT REPAIR GUIDE

6. BAD USB FUNCTION

When USB memory is connected to USB jack, It can’t recognize automatically.

6-1. USB JACK (JK301)

6-1-1. Solution

Replace JK301 (USB Jack)

6-1-2. How to troubleshoot (Countermeasure)

1) Check JK301 pin soldering.

2) If there is short soldering on pin JK301, re-soldering pin JK301.

3) Check FFC wafer CN101 and CN301’s soldering status,

If issue is still NG, check FFC cable status.

4) Check X500’s waveform. If it is abnormal signal, replace X500.

5) If issue is still NG, replace IC500.

6-1-3. Service hint (Any picture / Remark)

IC500

IC301

X500

CN301

CN101

< FRONT board top view > < MAIN board top view >

2-8

ONE POINT REPAIR GUIDE

7. NO SPEAKER OUTPUT

When unit is connected to Speaker using speaker cable, no speaker output.

7-1. IN OPTICAL / COAXIAL INPUT

7-1-1. Solution

Replace IC401

7-1-2. How to troubleshoot (Countermeasure)

1) Check signal at X400.

- If the clock doesn’t come out, replace X400.

2) Check signal at IC401 pin9, 10.

- If the clock doesn’t come out, check I2C trace or IC100.

3) Check the signal of IC402 pin12, 14, 16, 18

- If the clock doesn’t come out, check I2S trace or IC200.

4) If problem still occurs, replace MAIN board

7-1-3. Service hint (Any picture / Remark)

IC200

X400

IC401

IC401

IC402

IC100

< MAIN board top view >

2-9

ONE POINT REPAIR GUIDE

When unit is connected to Speaker using speaker cable, no speaker output.

7-2. IN PORTABLE / AUX / TUNER INPUT

7-2-1. Solution

Replace IC400.

7-2-2. How to troubleshoot (Countermeasure)

1) Check IC400 pin7 ~ 12.

- If the analog signal doesn’t come out, check the signal trace.

2) Check signal at IC400 pin1, 2

- If the clock doesn’t come out, check I2C trace or IC100.

3) Check the signal of IC400 pin 42, 43, 44.

- If the clock doesn’t come in, check I2S trace or IC401.

4) Check the signal of IC400 pin41.

- If the clock doesn’t come out, replace IC400.

7-2-3. Service hint (Any picture / Remark)

IC400

< MAIN board bottom view >

2-10

ONE POINT REPAIR GUIDE

When unit is connected to Speaker using speaker cable, no speaker output.

7-3. AMP BOARD

7-3-1. Solution

Replace AMP board.

7-3-2. How to troubleshoot (Countermeasure)

1) Check voltage at CN602.

- If 36 V, 14 VA, 3.7 V voltage doesn’t come out, re-soldering CN602.

2) Check voltage at IC701, IC702, IC703.

- If 36 V, 12 V voltage doesn’t come out, check SMPS board.

3) Check the signal of pin4 at CN601.

- If this pin is low, replace IC701, IC702, IC703.

4) If problem still occurs, replace AMP board.

7-3-3. Service hint (Any picture / Remark)

3.7V

36V

IC613

12V

CN601 PIN 4

< AMP board top view >

2-11

ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER SUPPLY ON SMPS BOARD

No 3.7 VA

YES

Is the F901 normal?

YES

Is TH901 normal?

YES

Is BD901 normal?

YES

Is the VCC

(11 V ~ 25 V) supplied to IC901

pin5?

YES

Power line of MAIN board is short.

NO

NO

NO

NO

Replace F901(same fuse).

Replace TH901.

Replace BD901.

Is D904/ D922/ D923 normal?

NO

Check or replace D904/ D922/ D923.

2-12

ELECTRICAL TROUBLESHOOTING GUIDE

No 6 VA

YES

Is the F901 normal?

YES

Is TH901 normal?

YES

Is BD901 normal?

YES

Is the VCC

(11 V ~ 25 V) supplied to IC901

pin5?

YES

Power line of MAIN board is short.

NO

NO

NO

NO

Replace F901(same fuse).

Replace TH901.

Replace BD901.

Is D921 normal?

NO

Check or replace D921.

2-13

ELECTRICAL TROUBLESHOOTING GUIDE

No 36 VA

YES

Is the Q901 normal?

YES

Is D928 normal?

YES

Is IC902 normal?

YES

Is the VCC

(11 V ~ 25 V) supplied to IC902

pin7?

YES

Power line of MAIN board is short.

NO

NO

NO

NO

Replace Q901.

Replace D928.

Replace IC902.

Is Q910 normal?

NO

Check or replace Q910.

2-14

ELECTRICAL TROUBLESHOOTING GUIDE

2. POWER SUPPLY ON MAIN BOARD

No 3.3 V

YES

VCC 3.7 V supplied to IC103

Is the

pin2?

YES

Is there

‘H’ signal at IC103

pin1?

YES

Check IC103 and replace.

No 5 V

NO

NO

Check 3.7 VA on SMPS board.

Check 3.3V_PWR_CTRL line

from IC100 (pin58).

YES

Is the

VCC 6 VA supplied to IC403

pin1?

YES

Is there

‘H’ signal at IC403

pin3?

YES

Check IC403 and replace.

NO

NO

Check 6 VA on SMPS board.

Check 5V_PWR_CTRL line

from IC100 (pin64).

2-15

ELECTRICAL TROUBLESHOOTING GUIDE

3. POWER SUPPLY ON AMP BOARD

No 36 V or 12 V

YES

Is the

CN102 pin1 is

High?

YES

Is there

good soldering status

IC701~703?

YES

Check SMPS and replace.

No 3.3 V

NO

NO

Check IC100 status in MAIN board.

Re-soldering or replace.

YES

Is the

VCC 3.7 V supplied to IC601

pin3?

YES

Is there

‘H’ signal at IC601

pin1?

YES

Check IC601 and replace.

NO

NO

Check 6VA on SMPS board.

Check AMP_PWR_CTRL line

from IC100 (pin37).

2-16

ELECTRICAL TROUBLESHOOTING GUIDE

4. POWER SUPPLY ON FRONT BOARD

No 3.3 V

YES

Is there

no issue 3.3 V line in FRONT

board?

YES

Is the

VCC 3.7 V supplied to IC103

pin2?

YES

Is there

‘H’ signal at IC103

pin1?

YES

Check IC103 and replace.

No 5 V

NO

NO

NO

Re-soldering or replace FRONT board.

Check 3.7 VA on SMPS board.

Check 3.3V_PWR_CTRL line

from IC100 (pin58).

YES

Is the

VCC 6 V supplied to IC302

pin2?

YES

Is there

‘H’ signal at IC302

pin1 ?

YES

Check IC302 and replace.

NO

NO

Check 6 V on SMPS board.

Check USB_PWR_CTRL line

from IC100 (pin38).

2-17

ELECTRICAL TROUBLESHOOTING GUIDE

5. SYSTEM PART

Power on

YES

“WELCOME”

display on VFD

OK?

YES

NO

IC100

3V3_MICOM, 3.3 V

OK?

YES

X100

20.000 MHz
OK?

YES

Replace

IC100 uPD78F1165.

NO

NO

Check D102

and SMPS board.

Replace X100.

MAIN board

It works properly.

3.3V, FL(+), FL(-)
OK?

YES

VFD

DO, STB, CLK

OK?

YES

Check DIG302.

2-18

NO

NO

Check Q105, Q102

and SMPS board.

Check IC100 and CN101.

FRONT board

ELECTRICAL TROUBLESHOOTING GUIDE

6. NO AUDIO OUTPUT

Tuner function

YES

IC400

pin11, 12 (TUNER_L/R)

OK?

YES

TU01

pin5, 6, 7, 8, 9 signal

OK?

YES

IC400

pin41 signal

OK?

YES

A

AUX / Portable function

NO

NO

NO

Check tuner audio.

Check IC100.

Check IC400.

YES

IC400

pin7, 8 (AUX_L/R) or pin9, 10 (POR_L/R)

OK?

YES

IC400

pin41 signal

OK?

YES

A

NO

NO

Check AUX, Portable trace

Check JK403, JK404

Check IC400.

2-19

ELECTRICAL TROUBLESHOOTING GUIDE

Optical / Coaxial function

YES

IC401

pin2, 5, 6 OPT_IN signal

NO

Check JK401 or replace.

OK?

YES

A

pin12, 14, 16, 18 I2S signal

IC402

NO

Check IC401 or replace.

OK?

YES

IC200

pin40, 54, 52, 51 I2S signal

NO

Check IC200 or replace.

OK?

YES

X602 signal OK?

YES

IC603

pin 50, 51 signal

OK?

YES

NO

NO

Check X602 or replace.

Check PWM I2C trace

or check IC100.

IC701

pin4, 5 or 10, 11 signal

OK?

YES

R720 signal is high?

YES

Speaker terminal

signal OK?

YES

It works properly.

2-20

NO

NO

NO

Check IC603 or replace.

Check IC701 or replace.

Check analog filter block.

ELECTRICAL TROUBLESHOOTING GUIDE

7. NO USB FUNCTION

No USB function

YES

JK301

pin1 VCC 5 V

OK ?

YES

JK301

Soldering status

OK?

YES

CN301,

CN101 soldering status

OK?

YES

IC500

3.3 V, 1.2 V
OK ?

YES

X500

signal OK?

YES

NO

NO

NO

NO

NO

Check IC302 and VCC 6 V line.

Re-soldering JK301.

Re-soldering CN301, CN101.

Check VCC_3V3 trace

or IC504, VCC12 trace.

Check X500 status.

R503,

R509, R510 signal

OK?

YES

Check USB device again.

NO

Check IC100 status.

2-21

ELECTRICAL TROUBLESHOOTING GUIDE

8. NO HDMI OUTPUT

No HDMI audio / video output

YES

JK802

pin18 VCC 5 V

OK ?

YES

JK802

pin19 HPD about 3.3 V

OK ?

YES

Is there

signal on R800,

R801?

YES

Is there

signal on X800?

YES

R152, R109

signal OK?

YES

NO

NO

NO

NO

NO

Check L812 and VCC 5 V line.

Check Hot Plug Detect Signal from TV.

Check IC800 VCC or replace IC800.

Check X800 or replace X800.

Check IC100 or replace IC100.

Check TV or receiver.

2-22

ELECTRICAL TROUBLESHOOTING GUIDE

9. NO HDMI INPUT

No HDMI audio / video output

YES

JK800,

JK801, JK803 pin18 VCC 5 V

OK ?

YES

JK800,

JK801, JK803 pin19 HPD about

3.3V OK ?

YES

Is there

signal on JK800, JK801, JK803

pin15,16?

YES

Check IC100’s status

or TX device (player).

NO

NO

NO

Check transmitter device.

Check IC800 status.

Check IC800 status.

2-23

1. SYSTEM PART-1 (MICOM)

1

FIG 1. IC100 uPD78F1164 XTAL 20 MHz

WAVEFORMS

1

6 7 5

2

3

4

FIG 2. IC100 uPD78F1164 VFD Control port

5

6

7

3 24

FIG 3. IC100 uPD78F1164 MCS Control port

2-24

2. SYSTEM PART-2 (HDMI)

8

FIG 4. IC800 ADV7622 (HDMI) XTAL

8

2-25

3. AUDIO PART-1 (DSP)

9

FIG 5. IC200 CS495314 (Audio DSP)

XTAL 24.576 MHz

9

10

11

12

13

MCLK

BCK

LRCK

DATA

FIG 6. IC200 CS495314 (Audio DSP)

I2S for Audio

13

11

10

12

2-26

4. AUDIO PART-2 (DIR)

14

FIG 7. IC401 CS8422 (DIR) XTAL 24.576 MHz

14

2-27

5. AUDIO PART-3 (MCS)

15

FIG 8. X500 MCS(MLC9800A) 12 MHz

16

17

18

15

16

17

FIG 9. IC500 MCS(MLC9800A) MCLK

18

FIG 10. IC500 MCS(MLC9800A) BCK FIG 11. IC500 MCS(MLC9800A) LRCK

2-28

6. AUDIO PART-4 (PWM)

19

FIG 12. IC603 PS9850 XTAL 19.2 MHz

2-29

19

MEMO

2-30

WIRING DIAGRAM

FFC Cable,

22p

AMP

CN602

CN601

CN100

CN102

CN901

Harness Cable,

14p

SMPS

MAIN

CN101

FFC Cable,

25p

Harness Cable,

22p

CN902

CN303

B’d to B’d, 4p

2-322-31

CN302

FRONTVOLUME

CN301

BLOCK DIAGRAM

VOLUME

PCB

VOL_UP, DOWN

Volume

KEY_AD

LED

KEY

KEY

#1

SPI(3)

#1

KEY

KEY

#1

#1

VFD Driver

MC3501

RCU

16bit NEC MICOM

uPD78F1165

(100pin)

I2
C

USB

FLD

E2P

ROM

DP,DN

12C
(3)

SPI(2)

MLC9800

AUX

DSP

Por / Mic

CS5346

ADC

Tuner

I2S(2CH)

I2S(2CH)

SDRAM

Flash

Coaxial

12C
(3)

74ALVC244

74ALVC244

74ALVC244

Optical

CS8422

DIR

I2S(6CH)

Optical

12C
(2)

PS9850

ARC SPDIF

AMP PCB

AMP

TAS5614

AMP

PWM

TAS5614

AMP

TAS5614

LPF

LPF

LPF

LPF

LPF

LPF

FRONT PCB

Main PCB

SMPS

Amp PCB

PCB

FlashSDRAM

AUDIO

DSP

CS495314

SPI
(1)

MAIN PCB

I2S(6CH)

I2S(6CH)

I2S(6CH)

I2S(6CH)

HDMI

TX/RX

TMDS

TMDS

HDMI

RX

HDMI

RX

ADV7622

12C

TMDS

(1)

TMDS

2-342-33

HDMI

RX

HDMI

TX

CIRCUIT DIAGRAMS

1. SMPS CIRCUIT DIAGRAM

12

11

10

9

8

IMPORTANT SAFETY NOTICE

WHEN SERVICING THIS CHASSIS, UNDER NO
CIRCUMSTANCES SHOULD THE ORIGINAL DESIGN
BE MODIFIED OR ALTERED WITH OUT PERMISSION
FROM THE LG CORPORATION. ALL COMPONENTS
SHOULD BE REPLACED ONLY WITH TYPES
IDENTICAL TO THOSE IN THE ORIGINAL CIRCUIT.

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

NOTE :

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

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

7

6

5

4

3

2

1

A

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

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

EBY61190341, REV4.1

SMPS

2011.01.28

2-362-35

2. AUDIO MICOM CIRCUIT DIAGRAM

12

11

10

1

9

8

7

6

5

4

3 24

6 7 5

3

2

1

: WAVEFORM NUMBER

A

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

EBY61190301(#2), REV5.4

AUDIO MICOM

2011.01.28

2-382-37

3. AUDIO DSP CIRCUIT DIAGRAM

12

11

10

9

8

7

10

9

6

5

4

3

2

13

11

12

1

: WAVEFORM NUMBER

A

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

EBY61190301(#3), REV5.4

AUDIO DSP

2011.01.28

2-402-39

4. HDMI CIRCUIT DIAGRAM

12

11

10

9

8

7

6

5

4

8

3

2

1

: WAVEFORM NUMBER

A

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

EBY61190301(#4), REV5.4

HDMI

2011.01.28

2-422-41

5. ADC / DIR CIRCUIT DIAGRAM

12

11

10

9

8

7

6

5

4

3

14

2

1

: WAVEFORM NUMBER

A

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

EBY61190301(#5), REV5.4

ADC/DIR

2011.01.28

2-442-43

6. MCS CIRCUIT DIAGRAM

12

11

10

9

8

16

17

7

6

5

18

15

4

3

2

1

: WAVEFORM NUMBER

A

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

EBY61190301(#6), REV5.4

MCS

2011.01.28

2-462-45

7. PWM CIRCUIT DIAGRAM

12

11

10

9

8

7

6

5

19

4

3

2

1

: WAVEFORM NUMBER

A

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

EBY61190311(#1), REV3.1

PWM

2011.01.28

2-482-47

8. AMP CIRCUIT DIAGRAM

12

11

10

9

8

7

6

5

4

3

2

1

EBY61190311(#2), REV3.1

A

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

AMP

2011.01.28

2-502-49

9. FRONT CIRCUIT DIAGRAM

12

11

10

9

8

7

6

5

4

3

2

1

A

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

FRONT-VFD

EBY61190321, REV3.3

2011.01.28

2-522-51

10. VOLUME CIRCUIT DIAGRAM

12

11

10

9

8

MEMO

7

6

5

4

3

2

1

A

B C D E F G H IJ

FRONT-VOLUME

EBY61190331, REV2.1

2011.01.28

2-542-53

CIRCUIT VOLTAGE CHART

Pin No. Desc. Voltage EE Mode

IC100 UPD78F1164 (TOP)

30 EVDD1 3.45 3.52

47 AVREF1 3.45 3.52

50 AVREF0 3.45 3.52

99 VDD 3.45 3.52

100 EVDD0 3.45 3.52

IC101 EEPROM

8 VCC 3.45 -

IC103 TJ3966

2 IN 3.7 -

IC200 CS495314

42 VDD1 1.78 0

55 VDD2 1.78 0

83 VDD3 1.78 0

95 VDD4 1.78 0

112 VDD5 1.78 0

125 VDD6 1.78 0

12 VDD7 1.78 0

22 VDD8 1.78 0

50 VDDIO1 3.29 0

62 VDDIO2 3.29 0

73 VDDIO3 3.29 0

89 VDDIO4 3.29 0

100 VDDIO5 3.29 0

120 VDDIO6 3.29 0

8 VDDIO7 3.29 0

28 VDDIO8 3.29 0

IC201 EM638165TSA-6G (BOTTOM)

1 VDD1 3.3 0

3 VDD3 3.3 0

9 VDD9 3.3 0

14 VDD14 3.3 0

27 VDD27 3.3 0

43 VDD43 3.3 0

49 VDD49 3.3 0

IC202 MX25L3205D

8 VDD 3.29 0

IC203 TJ3965DP

2 IN 3.7 -

3 OUT 1.8 -

IC301 MC3501

9 VDD 3.3 0

51 VDD 3.3 0

Pin No. Desc. Voltage EE Mode

IC302 LM29152RS-ADJ

2IN6 -

4 OUT 5 -

IC400 CS5346_ADC (BOTTOM)

5 VLC 3.3 -

14 VA 5 -

36 VLS 3.29 -

46 VD 3.29 -

IC401 CS8422_DIR

4 VA 3.29 0

19 V_REG 3.29 0

22 VL 3.29 0

IC402 74HCT244

20 Vin 3.29 -

IC403 TJ5205-ADJ

1IN6 -

5 OUT 5 -

IC500 MLC9800

2 AVDD33 3.3 0

30 VDD33 3.3 0

51 VDD33 3.3 0

84 VDD33 3.3 0

113 VDD33 3.3 0

115 USBVDD33 3.3 0

IC501 74HCT244

20 Vin 3.29 -

IC503 EM638165TSA-6G (BOTTOM)

1 VDD1 3.3 0

3 VDD3 3.3 0

9 VDD9 3.3 0

14 VDD14 3.3 0

27 VDD27 3.3 0

43 VDD43 3.3 0

49 VDD49 3.3 0

IC504 AZ1117BH-1.2 FIXED

3 Vin 3.3 -

4 Vout 1.2 -

IC505 MX25L3205D (BOTTOM)

8 VDD 3.29 0

IC506 CP2.0B

5 VCC 3.3 -

IC601 AP2128K-ADJTRG1

3 Vin 3.7 -

Pin No. Desc. Voltage EE Mode

4 Vout 3.3 -

IC603 PS9850

16 VDD_IO 3.3 0

24 VDD_IO 3.3 0

29 VDD_IO 3.3 0

32 VDD_IO 3.3 0

35 VDD_IO 3.3 0

40 VDD_IO 3.3 0

48 VDD_IO 3.3 0

IC701 TAS5614A

25 GVDD_C 12 0

26 GVDD_D 12 0

55 GVDD_A 12 0

56 GVDD_B 12 0

30 PVDD_D 36 0

31 PVDD_D 36 0

38 PVDD_C 36 0

39 PVDD_C 36 0

42 PVDD_B 36 0

43 PVDD_B 36 0

50 PVDD_A 36 0

51 PVDD_A 36 0

IC702 TAS5614A

25 GVDD_C 12 0

26 GVDD_D 12 0

55 GVDD_A 12 0

56 GVDD_B 12 0

30 PVDD_D 36 0

31 PVDD_D 36 0

38 PVDD_C 36 0

39 PVDD_C 36 0

42 PVDD_B 36 0

43 PVDD_B 36 0

50 PVDD_A 36 0

51 PVDD_A 36 0

IC703 TAS5614A

25 GVDD_C 12 0

26 GVDD_D 12 0

55 GVDD_A 12 0

56 GVDD_B 12 0

30 PVDD_D 36 0

31 PVDD_D 36 0

38 PVDD_C 36 0

Pin No. Desc. Voltage EE Mode

39 PVDD_C 36 0

42 PVDD_B 36 0

43 PVDD_B 36 0

50 PVDD_A 36 0

51 PVDD_A 36 0

IC800 ADV7622

2 CVDD 1.8 0

21 CVDD 1.8 0

34 CVDD 1.8 0

110 CVDD 1.8 0

129 CVDD 1.8 0

36 TXPVDD 1.78 0

37 TXPLVDD 1.78 0

45 TXAV 1.78 0

55 TXAV 1.78 0

61 DVDD 1.78 0

81 DVDD 1.78 0

93 DVDD 1.78 0

126 DVDD 1.78 0

6 TVDD 3.3 0

12 TVDD 3.3 0

25 TVDD 3.3 0

31 TVDD 3.3 0

114 TVDD 3.3 0

120 TVDD 3.3 0

133 TVDD 3.3 0

139 TVDD 3.3 0

IC802 74HCT244 (BOTTOM)

20 Vin 3.29 -

IC803 AZ1117BH-ADJ

3 Vin 3.3 -

4 Vout 1.8 -

IC804 AZ1117BH-ADJ

3 Vin 3.3 -

4 Vout 1.8 -

IC805 TJ3965ADJ

2 IN 3.7 -

3 OUT 3.3 -

2-562-55

PRINTED CIRCUIT BOARD DIAGRAMS

1. MAIN P. C. BOARD

(TOP VIEW)

(BOTTOM VIEW)

2-582-57

2. SMPS P. C. BOARD

(TOP VIEW) (BOTTOM VIEW)

NOTE) Warning

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

2-602-59

3. AMP P. C. BOARD

(TOP VIEW) (BOTTOM VIEW)

2-622-61

4. FRONT P. C. BOARD

(TOP VIEW)

(BOTTOM VIEW)

2-642-63

5. VOLUME P. C. BOARD

(TOP VIEW)

MEMO

(BOTTOM VIEW)

2-662-65

SECTION 3

CABINET & MAIN CHASSIS

CONTENTS

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

1. CABINET AND MAIN FRAME SECTION ................................................................................................. 3-3

2. SPEAKER SECTION ................................................................................................................................ 3-7

2-1. CENTER SPEAKER EXPLODED VIEW ............................................................................................. 3-7

2-2. FRONT SPEAKER EXPLODED VIEW ............................................................................................... 3-8

2-3. REAR SPEAKER EXPLODED VIEW .................................................................................................. 3-9

2-4. PASSIVE SUBWOOFER EXPLODED VIEW .................................................................................... 3-10

3. PACKING ACCESSORY SECTION ....................................................................................................... 3-11

3-1

MEMO

3-2

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION

462

279

A43

A50

260

452

265

275

CABLE1

B

464

462

D

468

CABLE2

250

A45

AMP

A

B

468

462

468

A46

464

C

CN901

A

C

MAIN

261

261

320

A44

CN902

A47

3-43-3

SMPS

468

D

F

F

300

MEMOMEMO

3-63-5

2. SPEAKER SECTION

2-1. CENTER SPEAKER EXPLODED VIEW

A700

3-7

2-2. FRONT SPEAKER EXPLODED VIEW

A800

3-8

2-3. REAR SPEAKER EXPLODED VIEW

A600

3-9

2-4. PASSIVE SUBWOOFER EXPLODED VIEW

A900

3-10

3. PACKING ACCESSORY SECTION

801 Owner’s manual

823 HDMI cable

825 FM antenna

900 Remote control

803 Packing

808 Batteries

824 AM antenna

827 Optimizer microphone

804 Bag

803 Packing

803B Speaker packing

803A Speaker packing

803D Speaker packing

802 Box

WIRE80 Front Left
WIRE81 Front Right
WIRE70 Center
WIRE90 Subwoofer
WIRE60 Front Left
WIRE61 Front Right

803C Speaker packing

Speaker cables

3-11

MEMO

3-12