LG MDS262V Schematic

KARAOKE MINI HOME THEATER

SERVICE MANUAL

MODEL : MDD262(MDS262V)

CAUTION

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

MODEL : MDD262(MDS262V)

SERVICE MANUAL

P/NO : AFN32840846 FEBRUARY, 2007

http://biz.lgservice.com

1-1

CONTENTS

SECTION 1 GENERAL

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

• NOTES REGARDING HANDLING OF THE PICK-UP

•

NOTES REGARDING COMPACT DISC PLAYER REPAIRS

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

LOCATION OF USERS CONTROLS.........................1-5

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

SECTION 2 EXPLODED VIEWS

CABINET AND MAIN FRAME SECTION..................2-1

TAPE DECK MECHANISM EXPLODED VIEW ........2-3

1. TAPE DECK MECHANISM

(A/R & A/S : RIGHT A/R DECK)........................2-3

2. TAPE DECK MECHANISM

(A/R & A/S : LEFT A/S DECK) ..........................2-5

DVD MECHANISM EXPLODED VIEW ......................2-7

SPEAKER EXPLODED VIEW ....................................2-9

MODEL : MDS262V (FRONT SPEAKERS)...........2-9

PACKING ACCESSORY VIEW.................................2-13

SECTION 3 AUDIO PART ELECTRICAL

AUDIO ELECTRICAL

TROUBLESHOOTING GUIDE....................................3-1

1. POWER (SMPS) ................................................3-1

2. P-SENS...............................................................3-2

3. VKK CHECK.......................................................3-2

4. MICOM PART CHECK I ....................................3-2

5. MICOM PART CHECK II ...................................3-3

6. IC103(KS4CD21CS) CHECK............................3-4

7. FLD DISPLAY CHECK ......................................3-5

8. PWM MODULATION PART CHECK................3-6

9. POWER AMP PART CHECK............................3-7

10. AUX FUNCTION CHECK..................................3-8

11. TUNER FUNCTION CHECK.............................3-9

12. TAPE FUNCTION CHECK ..............................3-10

13. TAPE PLAY PART CHECK..............................3-11

14. TAPE REC PART CHECK...............................3-12

INTERNAL BLOCK DIAGRAM OF ICs...................3-13

1. ES6838 ..............................................................3-13

2. HA12237F..........................................................3-14

3. PS9829B............................................................3-15

4. PT6324...............................................................3-15

5. STR-S6757IF1905 ............................................3-16

6. TAS5142.............................................................3-17

7. U1739EJ2V1UD00/KF2_E ...............................3-18

WIRING DIAGRAM ....................................................3-20

BLOCK DIAGRAM.....................................................3-22

1. SMPS BLOCK DIAGRAM...............................3-22

2. MAIN & FRONT BLOCK DIAGRAM ..............3-24

SCHEMATIC DIAGRAMS .........................................3-26

1. SMPS SCHEMATIC DIAGRAM.......................3-26

2. MAIN SCHEMATIC DIAGRAM ........................3-28

3. AMP SCHEMATIC DIAGRAM..........................3-30

4. DECK SCHEMATIC DIAGRAM .......................3-32

5. FRONT SCHEMATIC DIAGRAM.....................3-34

PRINTED CIRCUIT DIAGRAMS...............................3-36

1. MAIN P.C.BOARD ............................................3-36

2. SMPS P.C.BOARD ..........................................3-40

3. FRONT P.C.BOARD ........................................3-42

SECTION 4 DVD PART ELECTRICAL

DVD ELECTRICAL

TROUBLESHOOTING GUIDE....................................4-1

1. POWER CHECK GUIDE...................................4-1

2. TEST & DEBUG FLOW.....................................4-2

3. USB PART ..........................................................4-7

WAVEFORMS ...............................................................4-8

1. WHEN POWER ON,

RESET & DATA ETC WAVEFORM ...................4-8

OPEN / CLOSE WAVEFORM AT POWER ON

.......4-9

STARTING ACTION WAVEFORM IN MD DEVICE

......4-9

4. FOCUS WAVEFORM (AT CD).........................4-10

5. FOCUS WAVEFORM (AT DVD)......................4-10

AT POWER ON, SPINDLE SIGNAL AT MD DECK

........4-11

AT FIRST ACTION, FOCUS SIGNAL A, B, C, D

....4-11

8. TRACKING SIGNAL..........................................4-12

9. RF WAVEFORM ................................................4-12

10. DISK TYPE JUGEMENT WAVEFORM...........4-13

SCHEMATIC DIAGRAMS .........................................4-15

1. MPEG SCHEMATIC DIAGRAM .....................4-15

2. SERVO SCHEMATIC DIAGRAM ...................4-17

3. INTERFACE SCHEMATIC DIAGRAM ...........4-19

PRINTED CIRCUIT DIAGRAM .................................4-21

DVD P.C.BOARD .................................................4-21

SECTION 5 REPLACEMENT PARTS LIST

........5-1

1-2

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.

SERVICING PRECAUTIONS

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 (1MΩ)

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.

CLEARING MALFUNCTION

You can reset your unit to initial status if malfunction occur(button malfunction, display, etc.). Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of the volume knob for more than 3 seconds. If you reset your unit, you must reenter all its settings(stations, clock, timer)

NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it.

2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord.

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 know 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 ARROWHEAD 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 INTENED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE.

1-5

LOCATION OF USERS CONTROLS

FRONT / BACK PANEL

6 7

MDD262 Model

MDT352 Model

1. NUMERIC buttons (0-9)

2. DISPLAY WINDOW

3. • ( )POWER button

• CLOCK button

• TIMER button

• DUBBING (DUBB.) / CD SYNCHRO RECORDING (CD SYNC.) / (ST./MO.) button

4. MULTI JOG

• MANUAL TUNING

• CD SKIP

• CLOCK ADJUST

• (b-KEY CON-#) KEY CONTROL

5. HEADPHONE Jack (PHONES): ø3.5 mm

6. USB ( ) connector

7. • FUNCTION SELECT buttons (TUNER, TAPE, KARAOKE/DVD/CD, AUX)

• EQ button

• XTS-PRO button

• USB button

• XDSS Plus button

• Volume control knob

8. PUSH EJECT position (TAPE 1)

9. PUSH EJECT position (TAPE 2)

10.• RECORD/RECORD PAUSE ( REC/ ) button

• TUN.(-/+) buttons -AUTO TUNING / REWIND / FAST FORWARD ( ) -TAPE/ SCAN ( ) /TEMPO (-/+) buttons -CD

• PRESET (-/+) buttons / TAPE REVERSE PLAY () button (OPTIONAL) / TAPE FORWARD PLAY () button

• STOP ( STOP) button

11. MIC JACKS (MIC1, MIC2): ø6.3 mm : OPTIONAL

12.MIC VOLUME knob

13.Remote control sensor

14.• OPEN/CLOSE ( OP/CL) button

• DISC SKIP (D.SKIP) button

• PLAY MODE, DEMO button

• SET/CD , RDS (OPTIONAL) button

15.DISC DOOR

16.• COMPONENT VIDEO OUT (PROGRESSIVE SCAN) (Y Pb Pr) Connector

• VIDEO OUT Connector

17.• FM/AM ANTENNA Connector

• AUXILIARY INPUT (AUX IN) connector

18.POWER CORD

19.SPEAKER Connectors (MDT352 Model)

20.SPEAKER Connectors (MDD262 Model)

1-6

1. POWER button

2. FUNCTION SELECT buttons (TUNER/BAND, DVD/KARAOKE, AUX, USB)

3. NUMERIC buttons (0-9)

4. TAPE FUNCTION buttons

• REVERSE PLAY ( )

• PLAY ( )

• REWIND / FAST FORWARD PLAY ( )

• TAPE 1-2 SELECT buttons (1-TAPE-2)

• RECORD / RECORD PAUSE ( / )

• TAPE STOP ( )

5. SETUP button

6. • ARROW buttons ( / )

(Selects an option in the menu)

• PRESET (-/+) buttons ( )

• TUN. (-/+) buttons ( )

7. SELECT/ENTER button

8. MENU button (Use the MENU button to display the menu screen included on DVD video discs.)

9. STOP ( ), PAUSE( )/ STEP, PLAY ( ) buttons

10.PROG./MEMO., REPEAT, REPEAT A-B buttons

11. EQ ,XTS-Pro, SOUND / FEMALE( ), AUDIO / MALE( ), SUBTITLE (S-TITLE), SHADOW, CLEAR buttons

12.ECHO VOL. ( ) buttons

13.MIC VOL. ( ) buttons

14.RDS, PTY buttons - OPTIONAL

15.XDSS plus, VSM (Virtual Sound Matrix), ZOOM, RETURN ( ) buttons

16.• MARKER, SEARCH, MUTE( ) buttons

• TEMPO (-/+)/ SCAN ( )

• KEY CON (b/#)/ SKIP ( )

17.VOLUME -/+ buttons

18.TITLE button (Use the TITLE button to display the title screen included on DVD video discs.)

19.DISPLAY button

20.DIMMER button

21.SLEEP button

22.DISC SKIP (D.SKIP) button

REMOTE CONTROL

PRESET

PRESET + +

PRESET

PRESET - -

SETUP

TEMPO

REPEA

MARKER

REPEA

T A-B

A-B

PROG./MEMO.

ZOOM

AUDIO

S-TITLE

RETURN

RDS

PTY

CLEAR

TITLE

DISPLA

SLEEP

DIMMER

AUX

DVD/

KARAOKE

POWER

/ENTER

SELECT

MUTE

TUNER/BAND

USB

D.SKIP

STSTOP

PLA

PAUSE/STEP

AUSE/STEP

ECHO VOL.

MIC VOL.

TUN. -

TUN. +

1 -

TAPE - 2

APE - 2

SHADOW

KEY

CON - #

b -

XTS Pro

XDSS plus

VSM

SOUND

1-7

SPECIFICATIONS

• GENERAL

Power supply Refer to the main label. Power consumption Refer to the main label. Net Weight 8.65kg (MDT352)

5.9kg (MDD262)

External dimensions

(W x H x D)

280 X 365 X 370mm

• TUNER/AMPLIFIER

FM Tuning Range 87.5 ~ 108.0MHz or 65 ~74MHz, 87.5 ~ 108.0MHz

Intermediate Frequency 10.7MHz Signal to Noise Ratio 60/55dB (Mono/Stereo) Frequency Response 140 ~ 10000Hz

AM Tuning Range 522 ~ 1620kHz or 520 ~ 1720kHz

Intermediate Frequency 450kHz Signal to Noise Ratio 30dB Frequency Response 140 ~ 1800Hz

Output Power Front: 130W + 130W (4Ω, THD 10%)(MDD262)

100W + 100W (4Ω, THD 10%)(MDT352)

Subwoofer: 150W (3Ω, THD 10%)(MDT 352)

T.H.D 0.5% Frequency Response 42 ~ 20000Hz Signal-to-noise ratio 75dB

• DVD/VCD/CD PLAYER • CASSETTE TAPE PLAYER

Frequency response (audio) 40 ~ 20000Hz Tape Speed 3000 ± 3% Signal-to-noise ratio (audio) More than 75dB (1kHz) (MTT-111. Signal-to-noise ratio (video) More than 55dB (1kHz) NORMAL-SPEED) Dynamic range (audio) More than 75dB Wow Flutter 0.25% Video output 1.0V (p-p), 75Ω (MTT-111, JIS-WTD) S-video output (Y) 1.0V (p-p), 75Ω F.F/REW. Time 120sec (C-60)

Component Video output (Y) 1.0V (p-p), 75Ω Signal to Noise Ratio 43dB

(Pb)/(Pr) 0.7V (p-p), 75Ω Channel Separation 45dB (P/B)/45dB (R/P)

Erase Ratio 55dB (MTT-5511)

• SPEAKERS

Speaker Name Front Speaker (L/R) (MDS352V / MDS262V) Type Bass Reflex 2Way 3Speaker Impedance 4Ω Frequency Response 55 ~ 20000Hz Sound Pressure Level 82dB/W (1m) Rated Input Power 130W Max. Input Power 260W Net Dimensions (W x H x D) 212 X 414 X 305mm Net Weight 6.3kg

Speaker Name Subwoofer (MDS352W) Type Bass Reflex 1Way 1Speaker Impedance 3Ω Frequency Response 50 ~ 1500Hz Sound Pressure Level 82dB/W (1m) Rated Input Power 180W Max. Input Power 360W Net Dimensions (W x H x D) 212 X 414 X 305mm Net Weight 6.3kg

1-8

MEMO

255

256

450

263

262

273

455

450

A26

A40

A47

A46

266

305

267

289

456

450

264

452

458

450

290

454

450

A00

257

255

259

A43

A44

253

453

253

254

252

450

CABLE4

CABLE3

CABLE1

CABLE5

CN201

P9701

P9702

260

MAIN

SMPS

291

A41

450

CABLE2

P5701

DVD

FRONT

252

450

282

258

2-1 2-2

SECTION 2 EXPLODED VIEWS

CABINET AND MAIN FRAME SECTION

001

A00

002

037

007

006

008

016

017

018

019

020

003

009

A02

A01

011

013

022

025

015

023

BRASS MOTOR PULLEY MAYBE CHANGED FOR WOW FLUTTER WHEN NECESSARY

RING FW MAYBE ADDED FOR WOW FLUTTER WHEN NECESSARY

2-3 2-4

TAPE DECK MECHANISM EXPLODED VIEW

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

2-5 2-6

A00

RING FW MAYBE ADDED FOR WOW FLUTTER WHEN NECESSARY

013

011

009

003

008

015

022

023

024

016

017

018

019

020

007

A03

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

2-7 2-8

416

151

159

165

164

417

166

417

167

416

177

175

172

180

417

170

419

417

418

169

A30

A26

181

432

431

435

430

438

035

021

035A

036

430

012A

439

025

024

030

156

155

153

173

169A

169B

169C

168

163

162

441

440

422

DVD MECHANISM EXPLODED VIEW

A80A

A80R

A80L

A80BR

A80BL

WIRE80

WIRE81

850

855

856

857

858

860

861

863

859

851

853

852

854

862

2-9 2-10

SPEAKER EXPLODED VIEW

MODEL : MDS262V (FRONT SPEAKERS)

2-11 2-12

MEMO MEMO

2-13

PACKING ACCESSORY VIEW

3-1

AUDIO ELECTRICAL TROUBLESHOOTING GUIDE

SECTION 3 AUDIO PART ELECTRICAL

1. POWER (SMPS)

POWER (SMPS)

YES

Replace IC 901,902

Check IC901, 902

Check the fuse

F901

NONO

YES

Check short of

P9701, P9702 line

Replace the fuse

Check

the DC V of C905.

If DC V is over

400V

Check BD901, LF901, 902

Check the

DC V of C981, C945.

If DC V is 6.1V

Check short of P9702 line

YES

Chcek the

DC V of C950, C951

If DC V is in

35.5V

Check short of P9701 line

Chcek the

DC V of C909, C903,

C921 If DC V is in 14~19V

and it is steady.

YES

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