Lg Mdt505 User manual

MINI HOME THEATER

SERVICE MANUAL

MODEL:

MDT505 (MDS505V/W)

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”

IN THIS MANUAL.

MODEL: MDT505(MDS505V/W)SERVICE MANUAL

0102,SEPTEMBER21827947NFA:ON/P

Website http://biz.lgservice.com

Internal Use Only

CONTENTS

SECTION 1 ........ GENERAL

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

SECTION 3 ........ ELECTRICAL

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

1-1

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

SECTION 1. GENERAL

1-2

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 magnet-

ism 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 stat-

ic 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 MΩ)Conductive

Sheet

Resistor

(1 MΩ)

Armband

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

POWER ON

Press number 0~9, press character

A~F (1~6 for a while)

DVD LOGO status

(N0 disc status)

Remote control

pause keyÖ1Ö4Ö7Ö2 in order

Use arrow key (▲/▼/◀/▶) to

move to appropriate position and

make changes

Press pause key once

Change will be applied

when power OFFÖON

NAME

OPT 1

OPT 2

OPT 3

OPT 4

OPT 5

OPT 6

OPT 7

OPT 8

OPT 9

OPT A

DETECT NEW EEPROM

(OPTION EDIT SCREEN)

HEX

1-5

SERVICE INFORMATION FOR EEPROM

1. How to update AUDIO MICOM program.

[Update using CD]

1. Change the filename to download as “MDS715_(Version).HEX”. Only upper cases are permitted.

ex) MDS715 : “MDS715_0709081.HEX”

2. Copy the file to the root folder of a CD and burn it.

3. Insert the CD to the SET, and move to the DVD function.

Then the upgrade process will be started with the upgrade information.

4. If the upgrade process is complete, the set will be rebooted with “Complete” message.

[Update using USB]

1. Change the filename to download as “MDS715_(Version).HEX”. Only upper cases are permitted.

ex) MDS715 : “MDS715_0709081.HEX”

2. Copy the file to the root folder of USB storage.

3. After Home-menu is displayed on Screen of SET, Put the USB into the SET.

Then the upgrade process will be started with the upgrade information.

4. If the upgrade process is complete, the set will be rebooted with “Complete” message.

2. How to update DVD program.

[Update using CD]

1. Copy DVD program(ex: LG_MDS715LD1_Version.Rom) to Root folder of CD, and burn it.

ex) P:LG_MDS715LD1_0911180.Rom

2. Insert the CD to the SET, then after a while the CD tray will be opened with upgrade information on

the screen.

3. Remove the CD, and press “PLAY” key in remote controller.

4. Remove and reconnect the power cable when it changes to logo screen from upgrade information.

Then the upgrade process is completed.

[Update using USB]

1. Copy DVD program(ex: LG_MDS715LD1_Version.Rom) to Root folder of the formatted USB and burn it.

ex) P:\LG_MDS715LD1_0911180.Rom

2. After Home-menu is displayed on Screen of SET, Put the USB into the SET.

Then the upgrade process will be started with the upgrade information.

3. Remove the USB, press "PLAY" key of the remote controller.

4. Remove and reconnect the power cable when it changes to logo screen from upgrade information.

Then the upgrade process is completed.

1-6

HOW TO UPDATE AUDIO MICOM & DVD PROGRAMS

SPECIFICATIONS

• GENERAL

Power supply 110~240 V, 50/60 Hz

Power consumption Refer to main label

Dimensions (W x H x D) 273 x 333 x 339 mm without foot

Net Weight (Approx.) 5.7 kg

Operating temperature 41 °F to 95 °F (5 °C to 35 °C)

Operating humidity 5 % to 90 %

Bus Power supply (USB) DC 5V 500mA

• INPUTS/ 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 0.6 Vrms, 47 kΩ, RCA jack (L, R) x 1

PORT. IN 0.5 Vrms (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 522 to 1 620 kHz, 520 to 1 710 kHz or 522 to 1 710 kHz

• AMPLIFIER

Stereo mode 150 W + 150 W (4 Ωat 1 kHz)

Surround mode

Front 150 W + 150 W (4 Ωat 1 kHz)

Center 70 W (6 Ωat 1 kHz)

Surround 70 W + 70 W (6 Ωat 1 kHz)

Subwoofer 200 W (3 Ωat 60 Hz)

1-7

1-8

• SPEAKERS

Front speaker (MDS505V)

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4ecnadepmI Ω

Rated Input Power 150 W

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Net Dimensions(W x H x D) 240 x 387 x 336 mm

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Passive Subwoofer (MDS505W)

rekaeps1yaW1epyT

3ecnadepmI Ω

Rated Input Power 200 W

W004rewoptupnI.xaM

Net Dimensions(W x H x D) 261 x 331 x 409 mm

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SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

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

1. CABINET AND MAIN FRAME SECTION (MDT505)................................................................................ 2-3

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

3. DVD DECK MECHANISM SECTION (DVM-H1723) ................................................................................ 2-7

4. SPEAKER SECTION .............................................................................................................................. 2-11

5. PACKING ACCESSORY SECTION ....................................................................................................... 2-13

2-1

2-2

MEMO

2-3 2-4

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION (MDT505)

A26

267A

464

267

A26

A45

A42

A43

A44

A47

268

464

464 464

276

464

266

451

A00

272

464

250

262

261

260

251

254

255

256

257

252

258

253

259

464

271

269

264

265

267A

464

267

270L

263L

270R

263R

CABLE1

CABLE3

CABLE4

CABLE5

CABLE2

VOLUME

FRONT USB

274

273

463

275

iPod

SMPS

464

A46

MAIN

463

463 463

464

300

464

278

279

455

277

2-5 2-6

2. TAPE DECK MECHANISM SECTION (A/R & A/S : RIGHT A/R DECK)

A00

003

009

011 009

A02

015

007

001

037

A01

018

017

006 020

019

022

023

025

2-7 2-8

3. DVD DECK MECHANISM SECTION (DVM-H1723)

151

155

159

170

163

162

177

172

167

166

175 180

137

012

A01

A02

012

430

164

173

165

153

156

153A

169A

169B

169C

035

430

010

181

A26

2-9 2-10

MEMOMEMO

2-11

4. SPEAKER SECTION

4-1. FRONT SPEAKER (MDS505V)

A60

2-12

4-2. PASSIVE SUBWOOFER (MDS505W)

A90

808 Battery

811 RCA Cable, 1 Pin(Black)

900 Remote Control

824 AM Loop Antenna

801 Owner’s Manual

803 Packing, Casing

802 Box

825 FM Wire Antenna

804 Bag

2-13

5. PACKING ACCESSORY SECTION

2-14

MEMO

SECTION 3

ELECTRICAL

CONTENTS

ELECTRICAL TROUBLESHOOTING GUIDE.................................................................................... 3-2

DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING ................................ 3-16

WIRING DIAGRAM ................................................................................................................................... 3-29

BLOCK DIAGRAM.................................................................................................................................... 3-31

CIRCUIT DIAGRAMS...............................................................................................................................3-33

1. SMPS - POWER CIRCUIT DIAGRAM ................................................................................................. 3-33

2. MAIN - MICOM CIRCUIT DIAGRAM.................................................................................................... 3-35

3. MAIN - PWM CIRCUIT DIAGRAM ....................................................................................................... 3-37

4. MAIN - AMP CIRCUIT DIAGRAM ........................................................................................................ 3-39

5. MAIN - DECK CIRCUIT DIAGRAM...................................................................................................... 3-41

6. MAIN - MPEG CIRCUIT DIAGRAM ..................................................................................................... 3-43

7. MAIN - SERVO CIRCUIT DIAGRAM ................................................................................................... 3-45

8. MAIN - I/O CIRCUIT DIAGRAM ........................................................................................................... 3-47

9. VFD CIRCUIT DIAGRAM ..................................................................................................................... 3-49

10. MIC & USB CIRCUIT DIAGRAM.......................................................................................................... 3-51

11. VOLUME CIRCUIT DIAGRAM ............................................................................................................. 3-53

12. IPOD CIRCUIT DIAGRAM (OPTIONAL PART) ................................................................................... 3-55

13. KARAOKE CIRCUIT DIAGRAM (OPTIONAL PART)........................................................................... 3-57

CIRCUIT VOLTAGE CHART................................................................................................................. 3-59

PRINTED CIRCUIT BOARD DIAGRAMS ......................................................................................... 3-61

1. MAIN P.C.BOARD ................................................................................................................................ 3-61

2. SMPS P.C.BOARD............................................................................................................................... 3-65

3. FRONT(VFD / USB & MIC / VOLUME) P.C.BOARD........................................................................... 3-67

4. IPOD P.C.BOARD (OPTIONAL PART)................................................................................................ 3-69

5. KARAOKE P.C.BOARD (OPTIONAL PART) ....................................................................................... 3-69

3-1