LG HT-552-TH, HT-552-THC, HT-552-THS, HT-552-THW Service manual

SERVICE MANUAL

http://biz.lgservice.com

MODEL : HT552TH SH52TH-C, SH52TH-S, SH52TH-W

DVD/CD RECEIVER

SERVICE MANUAL

P/NO : AFN31640733 DECEMBER, 2006

MODEL : HT552TH

SH52TH-C, SH52TH-S, SH52TH-W

1-1

[CONTENTS]

SECTION 1. GENERAL

• SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

• ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

• SERVICE INFORMATION FOR EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

• SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

SECTION 2. AUDIO PART

• AUDIO TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

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

• BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

• CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

SECTION 3. DVD & AMP PART

• ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

• DVD & AMP CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22

• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28

SECTION 4. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1

SECTION 5. SPEAKER PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1

SECTION 6. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

1-2

SERVICING PRECAUTIONS

NOTES REGARDING HANDLING OF THE PICK-UP

1. Notes for transport and storage

1) The pick-up should always be left in its conductive bag until immediately prior to use.

2) The pick-up should never be subjected to external pressure or impact.

2. Repair notes

1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.

2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or damage to the printed-circuit board.

3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason the adjustment point and installation screws should absolutely never be touched.

4) Laser beams may damage the eyes! Absolutely never permit laser beams to enter the eyes! Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.

5) Cleaning the lens surface If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cotton swab should be used, taking care not to distort this.

6) Never attempt to disassemble the pick-up. Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.

Storage in conductive bag

Drop impact

NEVER look directly at the laser beam, and don’t let contact fingers or other exposed skin.

Magnet

How to hold the pick-up

Conductive Sheet

Cotton swab

Pressure

SECTION 1. GENERAL

1-3

NOTES REGARDING COMPACT DISC PLAYER REPAIRS

1. Preparations

1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components can be damaged, and for that reason components should be handled with care.

2) The pick-up is composed of many optical components and other high-precision components. Care must be taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnetism is present, or where there is excessive dust.

2. Notes for repair

1) Before replacing a component part, first disconnect the power supply lead wire from the unit

2) All equipment, measuring instruments and tools must be grounded.

3) The workbench should be covered with a conductive sheet and grounded. When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is because there is the possibility of damage by static electricity.)

4) To prevent AC leakage, the metal part of the soldering iron should be grounded.

5) Workers should be grounded by an armband (1M Ω)

6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent static electricity changes in the clothing to escape from the armband.

7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.

Resistor (1 Mohm)

Conductive Sheet

Resistor (1 Mohm)

Armband

1-4

ESD PRECAUTIONS

Electrostatically Sensitive Devices (ESD)

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off

any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed for potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surface

such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can

generate electrical charges sufficient to damage ESD devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD

devices.

6. Do not remove a replacement ESD device from its protective package until immediately before you are

ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive materials).

7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the

protective material to the chassis or circuit assembly into which the device will by installed.

CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER

SAFETY PRECAUTIONS.

8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion

such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity sufficient to damage an ESD device).

CAUTION. GRAPHIC SYMBOLS

THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE.

SERVICE INFORMATION FOR EEPROM(DVD PART)

POWER ON

*Refer to page 6-1.

DETECT NEW EEPROM

DVD LOGO Status (NO Disk status)

Remotecontrol Pause key-->1-->4-->7-->2 in order.

Press number 0~9, Press charater A~F (1~6 for a while)

Use arrow key ( ) to move to approprite position and make changes

Press pause key once

(OPTION EDIT SCREEN)

NAME HEX

OPT 1 00 OPT 2 00 OPT 3 00 OPT 4 00 OPT 5 00 OPT 6 00 OPT 7 00 OPT 8 00 OPT 9 00 OPT A 00 OPT B 00 OPT C 00 OPT D 00 OPT E 00 OPT F 00 OPT G 00

Change will be applied when power

OFF-->ON.

1-5

SERVICE INFORMATION FOR EEPROM (AMP PART)

POWER ON

FLD no disc status

Remotecontrol ‘2’ + Front ‘STOP’ push same timing during 5s

DETECT NEW EEPROM (OPTION EDIT SCREEN)

FLD ‘00….

Use arrow key ( ) move to appropriate position and make changes

Press ENTER key once

FLD ‘write ok’ or ‘up ok’

Remotecontrol ‘2’ + Front ‘STOP’ push same timing

NAME HEX

00 86 01 FA 02 23 03 00 04 00

FLD display E2P CLR or EP CLR

Auto power off

1-6

1-7

SPECIFICATIONS

GENERAL

Power supply Refer to main label. Power consumption Refer to main label. Net Weight 3.6 kg External dimensions (W x H x D) 430 x 70 x 311 mm Operating conditions Temperature: 5°C to 35°C, Operation status: Horizontal Operating humidity 5% to 85% Laser Semiconductor laser, wavelength 650 nm

CD/DVD

Signal system PAL 625/50, NTSC 525/60 Frequency response (audio) 200 Hz to 18 kHz Signal-to-noise ratio (audio) More than 75 dB (1 kHz, NOP -6 dB, 20 kHz LPF/A-Filter) Dynamic range (audio) More than 70 dB Harmonic distortion (audio) 0.5 % (1 kHz, at 1W position) (20 kHz LPF)

VIDEO

Video input 1.0 V (p-p), 75 Ω, negative sync., RCA jack x 1 Video output 1.0 V (p-p), 75 Ω, negative sync., RCA jack x 1/ SCART (TO TV) COMPONENT VIDEO OUT (Y) 1.0 V (p-p), 75 ohms, negative sync, RCA jack x 1

(PB)/(PR) 0.7 V (p-p), 75 ohms, RCA jack x 1

TUNER FM

Tuning Range 87.5 - 108.0 MHz or 65.0 - 74.0 MHz, 87.5 - 108.0 MHz Intermediate Frequency 10.7 MHz Signal-to Noise Ratio 60 dB (Mono) Frequency Response 140 - 8,000 Hz

AM [MW]

Tuning Range 522 - 1,620 kHz or 520 - 1,720 kHz Intermediate Frequency 450 kHz

AMPLIFIER

Stereo mode 70 W + 70 W (4Ω at 1 kHz, THD 10 %) Surround mode Front: 70 W + 70 W (THD 10 %)

Center*: 70 W Surround*: 70 W + 70 W (4Ω at 1 kHz, THD 10 %)

Subwoofer*: 150 W (3Ω at 30 Hz, THD 10 %) Inputs AUDIO IN, OPTICAL IN Outputs MONITOR OUT, EURO AV (TO TV) OUT

COMPONENT VIDEO OUT

SPEAKERS

Front/Rear Speaker Center speaker Passive Subwoofer

(SH52TH-S) (SH52TH-C) (SH52TH-W) Type 2 Way 3 Speaker 2 Way 3 Speaker 1 Way 1 Speaker Impedance 4 Ω 4 Ω 3 Ω Frequency Response 100 - 20000 Hz 150 - 20000 Hz 40 - 1500 Hz Sound Pressure Level 82 dB/W (1m) 82 dB/W (1m) 80 dB/W (1m) Rated Input Power 70 W 70 W 150 W Max. Input Power 140 W 140 W 300 W Net Dimensions (W x H x D) 260 x 1100 x 260 mm 330 x 86 x 121 mm 212 x 395 x 341 mm Net Weight 3.0 kg 1.15 kg 6.0 kg

(* Depending on the sound mode

settings and the source, there may be no sound output.)

2-1

SECTION 2. AUDIO PART

AUDIO TROUBLESHOOTING GUIDE

1. POWER SUPPLY CIRCUIT

Insert power cord

YES

Turn power on.

Check power plug and power supply circuit.

Check power supply circuit.

Check laser circuit.

Check focus circuit.

Check disc.

Check tracking servo circuit.

Check audio circuit.

Does red power led turn on?

Is power on?

Does initial read work?

Does it play?

Does it output audio?

2-2

2. FRONT CIRCUIT (1/2)

YES

YES YES

YES

NO NO

Reconnect it. (Refer to notice *1)

Tuner off the red led? Check if the PN301 is ok?

Refer to smps part.

Check pattern and resoldering

Is digitron on normally?

Check if all buttons are ok?

Check if the front power is ok?(*2)

Check if the DIS301 is ok?

Check if the remotecontrol is ok?

Power on.

Front b/d ok.

*1 : When it is needed to reconnected FFC cable into PN301

Short 1pin of PN103 with 18pin of CN901 in amp part

*2 : PN603 Pins.

PIN1 : -35 VKK PIN2 : -30 FL+ PIN3 : -33 FLPIN7 : +5V PIN13 : +5VA

2-3

3. FRONT CIRCUIT (2/2)

YES

Reffer to power(SMPS).

Replack R345 ~ R350, R154.

Check if the power part of the front is ok?

Check if R345~R350, R150 ok?

Refer to micom circuit.

YES

Reffer to power(SMPS).

Reffer to micom circuit.

Check rm circuit

Check if the power part of the front is ok?

Check if the remotecontrol waveform of the PN301 pin11 is ok?

Check if the RC2 voltage is ok(5V)?

YES

Resoldering or replace RC2.

2-4 2-5

WIRING DIAGRAM

CABLE4 EAD35201302

HDMI JACK

SCART JACK AV JACK

COMPONENT S/W

MAIN PCB

561-711O

PN206

6630XE00123

P4401

23PIN

PN203

6630XE00120

PN202

6630XE01224

CABLE3 EAD35201502

15PIN

EAD35219501

PN602

6630XE001206630XE00124

PN601

OPTICAL IN

TUNER

6630XE00118

PN103

CN902CN901

EAD35214501

CN602

561-715N

14PIN

EAD35214501

SPEAKER TERMINAL

AMP PCB

SMPS PCB

HEAT SINK

FAN

ACK

PN603

561-661B

KEY PCB

CABLE2 EAD35632101

CN301

EAD35219301

PN204

PN202 6630R-FB05K

11PIN

MIC1

3PIN

6630XE00111

USB

MIC2

STEREO

9PIN

P4402

CABLE1 EAD35201101

6630XE00109

EAD35219501

561-711C

PN302

PN301

6630R-FB05R

VFD

FRONT PCB

VOLUME

2-6 2-7

BLOCK DIAGRAM

IC508

IC601

DVD_DI

DVD_CLK

DVD_CE

DVD_DO

BLE

PORTA

TAS5152

IC501

IC203

NJM4580

OPAMP

IC204

AK5358

ADC

IP9009A

2-8 2-9

CIRCUIT DIAGRAMS

1. SMPS(POWER) CIRCUIT DIAGRAM

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

NOTES) Symbol denotes AC ground.

NOTES) Symbol denotes DC chassis ground.

NOTE) Warning

NOTE) Parts that are shaded are critical NOTE) With respect to risk of fire or NOTE) electricial shock.

IMPORTANT SAFETY NOTICE

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

COMPONENTS ARE SHADED ON THE SCHEMATIC FOR EASY IDENTIFICATION.

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

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.