LG MDT355, MDS355V, MDS355W Service manual

MODEL: MDT355(MDS355V/MDS355W)SERVICE MANUAL

Internal Use Only

Website http://biz.lgservice.com

DVD Mini Hi-Fi System

SERVICE MANUAL

P/NO : AFN75496339 JUNE, 2011

MODEL: MDT355(MDS355V/MDS355W)

CAUTION

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

CONTENTS

SECTION 1 ........ SUMMARY

SECTION 2 ........ CABINET & MAIN CHASSIS

SECTION 3 ........ ELECTRICAL

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

1-1

SECTION 1

SUMMARY

CONTENTS

SERVICING PRECAUTIONS ................................................................................................................... 1-3

ESD PRECAUTIONS .................................................................................................................................. 1-5

SERVICE INFORMATION FOR EEPROM .......................................................................................... 1-6

SOFTWARE UPGRADE PROCESS ..................................................................................................... 1-7

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

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

Storage in conductive bag

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

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

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.

Drop impact

Pressure

Magnet

How to hold the pick-up

Cotton swab

Conductive Sheet

(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.

1-3

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 (1 MΩ)

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 MΩ)

Conductive Sheet

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

POWER ON

FLD no disc status

Remote control ‘2’ + Front ‘STOP’

push same timing during 5s

FLD ‘OP-0….

Move to appropriate position

and make changes

with Rmc ‘skip, mode, play’ key.

Press STOP key

FLD ‘write ok’

DETECT NEW EEPROM (OPTION EDIT SCREEN)

NAME

OPT 0 OPT 1 OPT 2 OPT 3 OPT 4 OPT 5 OPT 6 OPT 7 OPT 8 OPT 9

HEX

F5 00 A4

00 09 81 20 50 00

Remote control ‘Fwd skip’ +

Front ‘STOP’ push same timing

FLD ‘E2P CLR’

Completed

1-6

SOFTWARE UPGRADE PROCESS

Important Notice : When ugrade the software running. Do not shunt down the power, it tmay damage the unit.

1. MICOM UPGRADE

1) Copy the software file into USB flash, as the file name is LG_MDT355__XXXXXXX.HE

2) Insert the USB flash into USB host.

3) Set Function to USB position.

Appear onto VFD UPGRADE

4) After finish, Set will automatically power off.

2. FLASH MEMORY UPGRADE

1) Copy the software file into USB flash, As the file name is LG_MDT355__XXXXXXX.RO

2) Insert the USB flash into USB host.

3) Set Function to USB position.

Appear onto VFD CODE 00

NO USB

4) Manual Power off and Power on is finish.

1-7

SPECIFICATIONS

• GENERAL

Power supply Refer to main label. Power consumption Refer to main label. Net Weight 5.27 kg External dimensions (W x H x D) ( 272 x 334 x 381 ) mm Operating conditions Temperature 5 °C to 35 °C, Operation status: Horizontal Operating humidity 5 % to 85 % Laser Semiconductor laser, wavelength, 760 to 800 nm

• TUNER FM/AM [MW]

FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz FM Intermediate Frequency 128 kHz AM Tuning Range 522 to 1 620 kHz, 520 to 1 710 kHz or 522 to 1 710 kHz AM Intermediate Frequency 45 kHz

• AMPLIFIER

Output Power Front : 100 W x 2 SUB Woofer : 150 W

• USB

Bus Power Supply (USB) DC 5 V 500 mA USB Version USB 2.0 or USB 1.1

• CD

Frequency Response 40 to 20 000 Hz Signal-to-noise ratio More than 60 dB Dynamic range More than 50 dB

• TAPE

F.F/REW Time 120 sec (C-60) Frequency Response 250 to 8 000 Hz Signal to Noise Ratio 40 dB Channel Separation 45 dB (P/B) / 40 dB (R/P) Erase Ratio 50 dB (MTT-5511)

• SPEAKERS

FRONT SUBWOOFER

Speaker name MDS355V MDS355W

Type 2 Way 2 Speaker 1 Way 1 Speaker

Impedance 4 Ω 3 Ω

Rated Input Power 100 W 150 W

Max. Input Power 200 W 300 W

Net Dimensions (W x H x D) ( 222 x 342 x 276 ) mm ( 272 x 334 x 332 ) mm

Net Weight 4.75 kg 5.3 kg

1-8

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

EXPLODED VIEWS ..................................................................................................................................... 2-3

1. CABINET AND MAIN FRAME SECTION (MDT355) ................................................................................ 2-3

2. TAPE DECK MECHANISM SECTION ...................................................................................................... 2-5

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

4. PACKING ACCESSORY SECTION ......................................................................................................... 2-9

2-1

MEMO

2-2

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION (MDT355)

263L

255

460

A41A

256

283

257

259

258

282

KEY3

451

452

266L

267L

250

264L

265

261

262

267R

451

A49

MIC

263R

264R

459

266R

KEY2

454

CABLE3

268

454

281

A26

A01

272

455

MAIN

456

A46

455

456

251

252

254

253

A00

453

452

A48

LED

A41L

454

A43

VFD

KEY1

A41R

271

458

CABLE2

CABLE1

USB

274

453

A45

SMPS

A47

456

457

273

300

270

269

2-3 2-4

2. TAPE DECK MECHANISM SECTION

A00

009

003

001

007

037

015

006

017

020

019

022

018

A01

023

025

011

A02

009

2-5 2-6

3. SPEAKER SECTION

3-1. LEFT/RIGHT SPEAKER (MDS355V)

A60

2-7

3-2. SUBWOOFER (MDS355W)

A90

2-8

4. PACKING ACCESSORY SECTION

824 AM antenna

Remote controller900

Packing803T

825 FM antenna

Battery808

Instruction Ass'y801

Bag804

803B

Packing

Box802

2-9

+ 37 hidden pages