LG HT303SD User Manual

MODEL : HT303SD(SH32SD-S/SH32SD-W)

SERVICE MANUAL

DVD/CD RECEIVER

SERVICE MANUAL

MODEL : HT303SD(SH32SD-S/SH32SD-W)

http://biz.lgservice.com

P/NO : AFN31640743

P/NO : AFN31640741 JANUARY, 2007

JANUARY, 2007

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

❍ SECTION 3. DVD & AMP PART

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

• DVD & AMP CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

❍ 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 lens.

6) Never attempt to disassemble the pick-up.
Spring has 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 allow
contact with fingers or other exposed skin.

Magnet

How to hold the pick-up

Conductive Sheet

Cotton swab

Pressure

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 or 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.

1-5

SERVICE INFORMATION FOR EEPROM (DVD PART)

POWER ON

DVD LOGO Status (NO Disk status)

Remote control
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 appropriate position and
make changes

Press pause key once

Change will be applied when power

OFF-->ON.

NAME

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

HEX

48
55
23
FF
22
05
FC
31
4D
00
00
00
00
00
00
00

DETECT NEW EEPROM
(OPTION EDIT SCREEN)

1-6

SERVICE INFORMATION FOR EEPROM (AMP PART)

POWER ON

FLD no disc status

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

FLD ‘OP-0….

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

Press ENTER key once

FLD ‘write ok’ or ‘up ok’

Remote control ‘2’ + Front ‘STOP’

push same timing

FLD display E2P CLR or EP CLR

Auto power off

NAME HEX

OPT 1 86
OPT 2 C2
OPT 3 10
OPT 4 00
OPT 5 00

DETECT NEW EEPROM
(OPTION EDIT SCREEN)

1-7

SPECIFICATIONS

GENERAL

Power supply Refer to main label
Power consumption Refer to main label
Net Weight 2.4 kg
External dimensions (W x H x D) 360 x 63 x 307 mm
Operating conditions Temperature: 5°C to 35°C, Operation status: Horizontal
Operating humidity 5% to 85%

CD/DVD

Laser Semiconductor laser, wavelength 650 nm
Signal system PAL 625/50, NTSC 525/60
Frequency response (audio) 160 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 output 1.0 V (p-p), 75 Ω, negative sync./ 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 160 - 8,000 Hz

AM [MW]

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

AMPLIFIER

Stereo mode 45W + 45W (Rated Output Power 30W, 4at 1 kHz, THD 10 %)
Surround mode Front: 45W + 45W (Rated Output Power 30W, THD 10 %)

Centre*: 45W
Surround*: 45W + 45W (Rated Output Power 30W, 4at 1 kHz, THD 10 %)
Subwoofer*: 75W (Rated Output Power 60W, 8at 30 Hz, THD 10 %)

Inputs AUX IN, MIC

SPEAKERS

Front/Center/Rear Speaker Passive Subwoofer

(SH32SD-S) (SH32SD-W)
Type 1 Way1 Speaker 1 Way1 Speaker
Impedance 4 Ω 8 Ω
Frequency Response 160 - 20,000 Hz 65 - 1,500 Hz
Sound Pressure Level 84 dB/W (1m) 87 dB/W (1m)
Rated Input Power 45 W 75 W
Max. Input Power 90 W 150 W
Net Dimensions (W x H x D) 98 x 101 x 105 mm 181 x 351 x 278 mm
Net Weight 0.52kg 3.4kg

(* 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.

Check power plug and power

supply circuit.

Turn power on.

OK

No

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

Does red power led

turn on?

Check power supply circuit.

Is power on?

Check tracking servo circuit.

Does it play?

Check audio circuit.

Does it output

audio?

Check laser circuit.

Check focus circuit.

Check disc.

Does red power led

turn on?

2-2

2. Front circuit (1/2)

Power on.

Reconnect it.(Refer to notice *1)

Refer to SMPS part.

Check pattern and resoldering

Front B/D ok.

Red LED turn off?

Check if

PN1301 is ok?

Is the Digitron on

correctly?

Check if the front

power is ok?(*2)

Check if all

buttons are ok?

Check if the remote

control is ok?

Check if

RM301 is ok?

Yes Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

1

2

NO

2-3

3. Front circuit (2/2)

Refer to

MICOM circuit.

Check if the

power part of the

front is ok?

Check if

R345~R350

ok?

Refer to power(SMPS).

No

Replace R345 ~ R350.

No

Yes

Yes

1

Resolder or

Replace RM301.

Check if the power

part of the front is ok?

Check if the remote

control waveform of PN3101

pin11 is ok?

Check if RM301

voltage is ok(5V)?

Refer to power(SMPS).

No

Check RM circuit

Refer to MICOM circuit.

Yes

No

Yes

No

Yes

2

2-4 2-5

WIRING DIAGRAM

061026

2-6 2-7

BLOCK DIAGRAM

061026

061026

IMPORTANT SAFETY NOTICE

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

CUIT.

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 UNTILTHE 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.

NOTE) Warning

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

NOTES) Symbol denotes AC ground.

NOTES) Symbol denotes DC chassis ground.

2-8 2-9

CIRCUIT DIAGRAMS

1. SMPS(POWER) CIRCUIT DIAGRAM

2-10 2-11

2. µ-COM(MAIN) CIRCUIT DIAGRAM

061026

2-12 2-13

3. MOTOR & SERVO CIRCUIT DIAGRAM

061026