LG HT356SD Service Manual

P/NO : AFN73951821 JANUARY, 2011

DVD HOME THEATER SYSTEM

SERVICE MANUAL

MODEL: HT356SD

(HT356SD, SH36SD-S/W)

CAUTION

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

Website http://biz.lgservice.com

Internal Use Only

MODEL: HT356SD (HT356SD, SH36SD-S/W)SERVICE MANUAL

[CONTENTS]

P SECTION 1. GENERAL

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

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

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

•

HOW TO UPDATE DVD & AUDIO MICOM PROGRAMS. .

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

. . . . . . . . . . . . . . . . . . . . . . . . 1-6

P SECTION 2. ELECTRICAL PART

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

• DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING . . . . . . . . . . . . . . . 2-13

• WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

• OVERALL BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29

• CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31

• CIRCUIT VOLTAGE CHART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41

• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45

P SECTION 3. EXPLODED VIEWS

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

• DECK MECHANISM EXPLODED VIEW (DP-15T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

• PACKING ACCESSORY SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

• SPEAKER SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

P SECTION 4. MECHANISM (DP-15T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

P SECTION 5. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

1-1

SECTION 1. GENERAL

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.

Storage in conductive bag

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.

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

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.

Drop impact

Pressure

Magnet

How to hold the pick-up

Cotton swab

Conductive Sheet

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.

1-2

Pressure

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.

Armband

Resistor (1 Mohm)

Conductive Sheet

1-3

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.

1-4

SERVICE INFORMATION FOR EEPROM

POWER ON

DVD LOGO Status (NO Disk status)

Remote control

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

Press number 0~9, Press character

A~F (1~6 for a while)

Use arrow key (

) to move to appropriate position and make changes

Press pause key once

DETECT NEW EEPROM (OPTION EDIT SCREEN)

NAME

OPT 1 OPT 2 OPT 3 OPT 4 OPT 5 OPT 6 OPT 7 OPT 8 OPT 9 OPT A

HEX

F1 00 A0

00 11 A0 30 50 0C

Change will be applied when power

OFF-->ON.

1-5

HOW TO UPDATE DVD & AUDIO MICOM PROGRAMS

1. The Whole Sequence

1) DVD program download.

2) Power cord out −> in.

3) Audio micom program download.

4) Remote control Pause key ‘\\’ + ‘1472’ for input options.

5) Enter into the system information for check the version, options and check sum.

6) Power off −> on.

Attention: After DVD program download, never input options and check the version before power cord out.

2. How to enter into System Information

1) Enter into SETUP menu in NO Disc.

2) Put on cursor [Highlight] 16:9 wide option of TV aspect in SETUP menu.

3) Press follow key in continuous using remote control. 1 −> 3 −> 9 −> 7 −> 1 −> 3 −> 9 −> ENTER

3. How to update program

3-1. How to update MTK DVD program

1) Rename the ﬁ lename to download as “LG_(MODEL NAME).ROM” in upper cases. Ex.) HT356 : “LG_HT356.ROM”

2) Copy the ﬁ le to the formatted USB, and burn it.

3) Move to the USB function, and insert the USB to the set. The upgrade information will be shown on the screen.

4) Remove the USB, press PLAY key of the remote control.

5) Remove and reconnect the power cable when it changes to logo screen from upgrade information. Then the upgrade process is completed.

3-2. How to update AUDIO MICOM program

1) Change the ﬁ lename to download as “(MODEL NAME)_(Version).HEX”. Only upper cases are permitted. Ex.) HT356 : HT356_0809262.HEX

2) Copy the ﬁ le to the root folder of USB storage.

3) Put the USB into the SET, and move to the USB function. Then the upgradeprocess will be started with the upgrade information.

4) If the upgrade process is complete, the set will be power off automatically with “Complete” message.

1-6

SPECIFICATIONS

• GENERAL

Power requirements Refer to main label. Power consumption Refer to main label. Dimensions (W x H x D) Approx. 360 x 65 x 320 mm without foot Net Weight (Approx.) 2.5 kg Operating conditions Temperature 5 °C to 35 °C (41 °F to 95 °F) Operating humidity 5 % to 90 %

• OUTPUTS

VIDEO OUT 1.0 V (p-p), 75 Ω, sync negative, RCA jack x 1 COMPONENT VIDEO OUT (Y) 1.0 V (p-p), 75 Ω, sync negative, RCA jack x 1

(Pb)/(Pr) 0.7 V (p-p), 75 Ω, RCA jack x 2 ANALOG AUDIO IN 2.0 Vrms (1 kHz, 0 dB), 600 Ω, RCA jack (L, R) x 1 PORT. IN 0.5 Vrms (3.5 mm stereo jack)

• SYSTEM

Laser Semiconductor laser, wavelength: 650 nm Signal system Standard NTSC/PAL color TV system Frequency response 20 Hz to 20 kHz (48 kHz, 96 kHz, 192 kHz sampling) Signal-to-noise ratio More than 80 dB Harmonic distortion 0.05 % at 1 W Dynamic range More than 85 dB Bus Power Supply (USB) DC 5 V 500 mA

• AMPLIFIER

Stereo mode 45 W + 45 W (4 Ω at 1 kHz) Surround mode Front 45 W + 45 W (THD 1 %) Center 45 W Surround 45 W + 45 W (4 Ω at 1 kHz) Subwoofer 75 W (8 Ω at 60 Hz)

• Tuner

FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz

1-7

• SPEAKERS Front Speaker

Type 1 Way 1 Speaker Impedance Rated 4 Ω Input Power 45 W Max. Input Power 90 W Net Dimensions (W x H x D) 113 x 113 x 84 mm Net Weight 0.34 kg

Rear Speaker

Type 1 Way 1 Speaker Impedance Rated 4 Ω Input Power 45 W Max. Input Power 90 W Net Dimensions (W x H x D) 113 x 113 x 84 mm Net Weight 0.38 kg

Center Speaker

Type 1 Way 1 Speaker Impedance Rated 4 Ω Input Power 45 W Max. Input Power 90 W Net Dimensions (W x H x D) 113 x 113 x 84 mm Net Weight 0.34 kg

Subwoofer

Type 1 Way 1 Speaker Impedance Rated 8 Ω Input Power 75 W Max. Input Power 150 W Net Dimensions (W x H x D) 155 x 325 x 265 mm Net Weight 3 kg

Note : Design and specifications are subject to change prior notice.

1-8

SECTION 2. ELECTRICAL PART

TROUBLESHOOTING GUIDE

1. Power Supply Circuit

INSERT POWER CORD.

YES

Turn power on.

YES

Is power on?

YES

Does it play?

YES

Does it output

audio?

YES

Check power supply circuit.

Check tracking servo circuit.

Check audio circuit.

2-1

2. Front circuit (1/2)

POWER ON.

YES

Is the Digitron on

correctly?

YES

Check if all

buttons are ok?

YES

Check if the remote

control is ok?

YES

Front B/D ok.

{

Check if

PN301 is ok?

YES

Check if the front

power is ok?

YES

Check if

DIS301 is ok?

Reconnect it.

Refer to SMPS part.

Check pattern and resoldering

2-2

3. Front circuit (2/2)

Check if the

power part of the

front is ok?

YES

Check if

R346~R349, R352, R370

ok?

YES

Refer to MICOM circuit.

Refer to power(SMPS).

Replace R346~R349, R352, R370.

Check if the

power part of the front

is ok?

YES

Check if the remote

control waveform of PN301

pin5 is ok?

YES

Check if RC301

voltage is ok(3.3V)?

YES

Resolder or Replace RC301.

Refer to power(SMPS).

Refer to MICOM circuit.

Check RM circuit

2-3

4. System operation flow

POWER ON.

1. Initializes SERVO, DSP & RISC registers.

2. Write RISC code to SDRAM.

3. Reset RISC.

Show LOGO.

YES

Tray closed?

Tray close to closed position.

SLED at inner

side?

SLED moves to inner position.

1. Judge whether have disc and disc type.

2. Jump to related disc reading procedure.

Recieve

OPEN/ CLOSE

Key?

YES

1. Execute Pressed Key & IR Key.

2. System operation routine loop.

1. Stop Playback & Open Tray.

2. Display tray open message & LOGO.

YES

Receive

CLOSE Key?

YES

2-4

5. Test & debug flow

TEST.

YES

Check the

AC voltage Power PCBA (110V

or 220V).

YES

Switch on the Power PCBA.

YES

Are the

DC Voltage outputs OK? (12V,

3.3V, 5V, 7V, 34V).

YES

Are 3.3V and

5V DC outputs normal on main

PCBA?

YES

Update

FLASH successfully?

YES

Check the POWER PART.

Check the regulators or diode.

1. Check 27MHz system clock.

2. Check system reset circuit.

3. Check FLASH R/W enable signal PRD, RWR.

4. Check FLASH Memory related circuit.

Replace FLASH.

2-5

YES

Power On.

YES

Show LOGO?

YES

Does Tray

move inside when it

is not at closed

position?

Flash

Memory operates

properly?

YES

SDRAM

works properly?

YES

MT1389L

VIDEO outputs

properly?

YES

Check AV cable

connection to TV set.

Normal

OPEN_SW,

CLOSE_SW

signal?

Check connection lines

between FLASH & MT1389L and the FLASH access time whether is suitable or not.

Check connection lines between SDRAM(IC503) & MT1389L and the SDRAM is damaged.

Check the related circuit of MT1389L IC501 Pins99, 102, 103, 104.

Check the load OPEN &

CLOSE switch.

YES

Normal

TROPEN & TRCLOSE

signal?

YES

Normal

LOAD+ & LOAD-

signal?

YES

Check AV cable connection between main PCBA and loader. (MECHA)

2-6

Check the Tray control IO pins

on MT1389L.

Check the Tray control MOTOR

& SERVO circuit IC400.

YES

Does

the SLED move to inner

side when it is at outer

position?

YES

Do not put in disc

and close tray.

Motor

Driver M_STBY

pin is high?

YES

Motor

Driver M_STBY

pin is High?

YES

SLED+ and

SLED- output

properly?

YES

Check the cable connection

with MECHA.

Check the connection line of M_STBY.

Check the related circuit of SLD.

Check the AMP circuit on motor driver.

Optical Lens

has movements for

searching Focus?

YES

Proper

Focus outputs

to motor driver?

YES

Proper F+ & F-

outputs?

YES

Check cable connection with

pick-up head.

2-7

Check Focus connection on

MT1389L and motor driver.

Check the AMP circuit on

motor driver.

YES

Laser

turns on when

reading disc?

YES

Put disc in?

YES

Disc ID is correct?

DVDLD or

CDLD output

property?

YES

Collector

voltage of power transistor

is OK?(Q403, Q405)

YES

Check cable connection

between transistor output and

pick-up head.

Laser off.

Proper

RF signal on

MT1389L.

Check the laser power circuit

on MT1389L and

connecting to power

transistor(Q403, Q405).

Check the related circuit on

laser power transistor.

Check the related circuit on

MT1389L RF signal.

YES

Does spindle rotate?

YES

Check the RF connection

between AM5890 and

Proper

SPINDLE signal on

MT1389L.

SPNP

SPNN output

properly?

Check the cable connection

between spindle and main

PCB.

2-8

MT1389L

YES

Check the SPINDLE related

circuit on MT1389L.

Check the spindle control AMP

circuit of motor driver.

YES

Focus on ok?

YES

Track On OK?

YES

Proper

signals on A, B, C,

D of MT1389L.

YES

Proper

CD_DVDCT signal on

MT1389L.

YES

Check CD_DVDCT connection

between AM5890 and

MT1389L.

Proper

CD_DVDCT signal on

MT1389L.

YES

Proper

TRACK signal

on MT1389L.

Check connections between MT1389L and pick-up head.

Check the related circuit on

MT1389L CD_DVDCT.

Check the related circuit on

MT1389L.

Check the TRACK connection

MT1389L

and motor driver.

Disc Playback?

YES

T+ & T- output

properly?

YES

Check cable connection

on pick-up head.

Check RF signal waveform.

2-9

Check the tracking control AMP

circuit on motor driver.

YES

Normal Audio

output when disc

playback?

YES

TEST END.

PWM IC

received correct data

stream?

YES

Normal

PWM IC out?(IC602).

YES

Check Digital AMP circuit

(IC701, IC702).

Check connection between IC602 BCK, LRCK, ADATA0.

Check the related circuit of PWM.(Check Audio out Pins28, 31, 33, 34, 37, 39, 42).

2-10

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