lg mcd112 aou

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MINI Hi-Fi SYSTEM SERVICE MANUAL MODEL : MCD112 (MCS112F) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. Website http://biz.lgservice.com MODEL : MCD112 (MCS112F) SERVICE MANUAL Internal Use Only P/NO : AFN72956656 APRIL, 2009

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Page 1: Lg Mcd112 Aou

MINI Hi-Fi SYSTEMSERVICE MANUAL

MODEL : MCD112 (MCS112F)

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

Website http://biz.lgservice.com

MO

DE

L: M

CD

112 (MC

S112F

)S

ER

VIC

E M

AN

UA

L

Internal Use Only

P/NO : AFN72956656 APRIL, 2009

Page 2: Lg Mcd112 Aou

1-1Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

CONTENTS

SECTION 1GENERALSERVICING PRECAUTIONS ................................1-2

• NOTES REGARDING HANDLINGOF THE PICK-UP

• NOTES REGARDING COMPACT DISCPLAYER REPAIRS

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

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

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

SECTION 2EXPLODED VIEWSCABINET EXPLODED VIEW................................2-1

TAPE DECK MECHANISM EXPLODED VIEW ....2-31. TAPE DECK MECHANISM

(A/S & A/S : RIGHT A/S DECK) ..................2-32. TAPE DECK MECHANISM

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

CD MECHANISM EXPLODED VIEW ...................2-7

SPEAKER EXPLODED VIEW ..............................2-9MODEL : MCS112F.........................................2-9

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

SECTION 3AUDIO PART ELECTRICALAUDIO ELECTRICALTROUBLESHOOTING GUIDE ..............................3-1

1. POWER (SMPS) .........................................3-12. P-SENS .......................................................3-23. VKK CHECK................................................3-24. MICOM PART CHECK I ..............................3-25. MICOM PART CHECK II .............................3-36. IC103(KS4CD21CS) CHECK......................3-47. FLD DISPLAY CHECK ................................3-58. PWM MODULATION PART CHECK...........3-69. POWER AMP PART CHECK ......................3-7

10. AUX FUNCTION CHECK ............................3-811. TUNER FUNCTION CHECK .......................3-912. TAPE FUNCTION CHECK ........................3-1013. TAPE PLAY PART CHECK ........................3-1114. TAPE REC PART CHECK .........................3-12

INTERNAL BLOCK DIAGRAM OF ICs ..............3-131. ES6838.......................................................3-132. HA12237F. ..................................................3-14

3. PS9829B ....................................................3-154. PT6324 .......................................................3-155. STR-S6757IF1905......................................3-166. TAS5142 .....................................................3-177. U1739EJ2V1UD00/KF2_E .........................3-18

WIRING DIAGRAM .............................................3-19

BLOCK DIAGRAMS ...........................................3-211. SMPS BLOCK DIAGRAM .........................3-212. MAIN & FRONT BLOCK DIAGRAM .........3-23

SCHEMATIC DIAGRAMS ...................................3-251. SMPS SCHEMATIC DIAGRAM ................3-252. MAIN SCHEMATIC DIAGRAM..................3-273. AMP SCHEMATIC DIAGRAM ...................3-294. DECK SCHEMATIC DIAGRAM.................3-315. FRONT SCHEMATIC DIAGRAM.................3-336. KEY-L SCHEMATIC DIAGRAM ...................3-357. KEY-R SCHEMATIC DIAGRAM...................3-36

PRINTED CIRCUIT BOARD DIAGRAMS...........3-371. MAIN P.C.BOARD .....................................3-372. FRONT P.C.BOARD..................................3-413. SMPS P.C.BOARD....................................3-434. KEY-L P.C.BOARD ....................................3-445. KEY-R P.C.BOARD ...................................3-44

SECTION 4 CD PART ELECTRICALCD ELECTRICALTROUBLESHOOTING GUIDE ..............................4-1

1. CD PART TROUBLESHOOTING................4-12. USB PART TROUBLESHOOTING..............4-9

WAVEFORMS OF MAJOR CHECK POINT .......4-10

SCHEMATIC DIAGRAMS ...................................4-131. CD SCHEMATIC DIAGRAM .....................4-132. USB SCHEMATIC DIAGRAM ...................4-15

PRINTED CIRCUIT BOARD DIAGRAM .............4-17CD P.C.BOARD .............................................4-17

SECTION 5 REPLACEMENTPARTS LIST............................................5-1

Page 3: Lg Mcd112 Aou

1-2 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

NOTES REGARDING HANDLING OF THE PICK-UP1. 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 notes1) 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/ordamage to the printed-circuit board.

3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reasonthe 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 surfaceIf there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as usedfor camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cottonswab 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 notuse any other liquid cleaners, because they will damage the lens.) Take care not to use too much of thisalcohol on the swab, and do not allow the alcohol to get inside the pick-up.

SERVICING PRECAUTIONS

SECTION 1 GENERAL

Page 4: Lg Mcd112 Aou

1-3Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

NOTES REGARDING COMPACT DISC PLAYER REPAIRS1. Preparations

1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These componentsare sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, componentscan 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 betaken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong mag-netism is present, or where there is excessive dust.

2. Notes for repair1) Before replacing a component part, first disconnect the power supply lead wire from the unit2) 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 isbecause 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 MALFUNCTIONYou 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 ofthe 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.

Page 5: Lg Mcd112 Aou

1-4 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

ESD PRECAUTIONS

Electrostatically Sensitive Devices (ESD)Some semiconductor (solid state) devices can be damaged easily by static electricity. Such componentscommonly are called electrostatically sensitive devices (ESD). Examples of typical ESD devices are inte-grated circuits and some field-effect transistors and semiconductor chip components. The following tech-niques 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, drainoff any electrostatic charge on your body by touching a know earth ground. Alternatively, obtain andwear a commercially available discharging wrist strap device, which should be removed for potentialshock 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 conductivesurface 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 ESDdevices.

6. Do not remove a replacement ESD device from its protective package until immediately before you areready to install it. (Most replacement ESD devices are packaged with leads electrically shorted togetherby conductive foam, aluminum foil or comparable conductive materials).

7. Immediately before removing the protective material from the leads of a replacement ESD device, touchthe 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 ALLOTHER SAFETY PRECAUTIONS.

8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmlessmotion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floorcan generate static electricity sufficient to damage an ESD device).

[CAUTION. GRAPHIC SYMBOLS]

THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL. WITHIN AN EQUILATERALTRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCEOF UNINSULATED "DANGEROUS VOLTAGE" THAT MAY BE OF SUFFICIENT MAGNI-TUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENED TOALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETYINFORMATION IN SERVICE LITERATURE.

Page 6: Lg Mcd112 Aou

1-5Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

LOCATION OF USERS CONTROLS

FRONT PANEL

1

2

3

4

5

6

7

8

9

10

11

1. POWERYou can set up the unit into an economic powersave mode. In the power-on status, press and hold

(POWER) for about 3 seconds. To cancelpower save mode, press (POWER).

2. ST./MONOPress ST./MONO. This will change the tuner fromstereo to mono and usually improve the reception.

3. MP3 OPT. (MP3 Optimizer)This function is optimized for compressible MP3files so that it improves the bass sound.

4. DEMOPress DEMO in power off state to demonstrate thefunction on display window. To cancel it, press or DEMO again.

5. Headphone jackConnect a headphone plug (ø3.5 mm) into the jackto listen to the sound through headphones (notsupplied).

6. CD tray

7. XTS - PROThe function creates the optimum sound for you toplay of the original sound. Each time you pressXTS - PRO, “XTS -- PRO ON” or “XTS -- PROOFF” is displayed in turn. (The XTS Pro functionwill not be operated when a headphone has beenconnected.)

8. D.SKIPIf more than one portable USB player is connectedto the system at the same time, press D.SKIP toselect one of them.

9. AUXYou can connect many other types of audio oraudio visual device to the system via the auxiliarysockets (AUX IN) on the back of the player.

10.VOLUMEControl the volume when using any function.

11.USB connector - OPTIONALConnect a remote USB compatible player here.

Page 7: Lg Mcd112 Aou

1-6 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

REMOTE CONTROL

10

12

13

14

9

8

2

3

4

5

6

7

1

11

1. Search for a folder of MP3/WMA files When a CD containing MP3/WMA files in severalfolders is being played, press PRESET/FOLDER toselect the folder you want to play.

2. Fall asleep while listening to your playerFirstly, start a radio station or music. Press SLEEPon the remote one or more times to select a delayof between 10 and 180 minutes, after which theplayer will turn off.

3. Use when playing a CD

4. Listen to your tracks again and againPress REPEAT once to repeat the track currentlyplaying. Press REPEAT twice to repeat the wholeCD, or if you’re listening to the whole folder ofMP3/WMA CD . The display will show what is beingrepeated.

5. Use when playing a cassette tape

6. Sound quality adjustmentYou can select a desired sound mode by using EQ.

7. Play any track on a CDPress the corresponding number buttons on theremote control.

8. Temporarily stop the soundPress the button again to return to the sound.

9. To change the functionsChange the functions between FM, AM, CD, AUX,USB or TAPE

10.Dimm the display light

11.For storing radio stationsIf you have saved radio stations using PROGRAM/MEMO, you can scroll through them and select one(see Listening to the radio).

12.eXtreme Dynamic Sound SystemReinforce the treble, bass and surround soundeffect. XDSS ON will show in the display. Pressagain for XDSS OFF.

13.RANDOMPress RANDOM, play tracks/files you can in a ran-dom order or cancel it.

14.See information about your musicMP3/WMA files often come with tags. The tag givesthe Title, Artist or Album. Press INFO while a file isplaying to see this information. If there are no tags,“NO ID3 TAG” or “NO WMA TAG” will show.

Page 8: Lg Mcd112 Aou

1-7Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

SPECIFICATIONS

• GENERALNet Weight 5.57kg (MCD212 Model)

5.36kg (MCD112 Model)External dimensions (WxHxD) 170 x 243 x 282mm

• TUNERFM Tuning Range 87.5 ~ 108.0MHz or 65 ~ 74MHz,

87.5 ~ 108.0MHzAM Tuning Range 522 ~ 1620kHz or 520 ~ 1720kHz

• AMPLIFIEROutput Power 100W + 100W (MCD212 Model)

50W + 50W (MCD112 Model)T.H.D 0.5%Frequency Response 40 ~ 20000HzSignal-to-noise ratio 75dB

• CDFrequency response 40 ~ 20000HzSignal-to-noise ratio 75dBDynamic range 75dB

• SPEAKERSMCS212F Type Bass Reflex 2 Way 2 Speaker

Impedance 4ΩRated Input Power 100WMax. Input Power 200WNet Dimensions (WxHxD) 220 x 342 x 270mmNet Weight (1EA) 3.46kg

MCS112F Type Bass Reflex 2 Way 2 SpeakerImpedance 4ΩRated Input Power 50WMax. Input Power 100WNet Dimensions (WxHxD) 200 x 337 x 228mmNet Weight (1EA) 2.92kg

Page 9: Lg Mcd112 Aou

1-8 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

MEMO

Page 10: Lg Mcd112 Aou

2-1 2-2

SECTION 2 EXPLODED VIEWSCABINET EXPLODED VIEW

255

256

E

F

G

IJ

H

A

B

B

M

N

A

JK

H

L

L

K

M

I

C

G

EF

D

A26

A41

A47

A46

266

263

305

451

267

289

456

450

264

458

450

450

450

290

290454

CABLE2

CABLE4

CN806

P9701

P9702

260

CD

MAIN

SMPS

291

257

255

259

253

253

254

450

N

N

C

450

450

A00

CABLE1

CABLE5

CN201

CABLE3

A43

A40

FRONT

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 11: Lg Mcd112 Aou

2-3 2-4

TAPE DECK MECHANISM EXPLODED VIEW1. TAPE DECK MECHANISM (A/S & A/S : RIGHT A/S DECK)

BRASS MOTOR PULLEY MAYBE CHANGEDFOR WOW FLUTTER WHEN NECESSARY

RING FW MAYBE ADDEDFOR WOW FLUTTER WHEN NECESSARY

001

002

006

007

008

016 017

018

019

020

003

A00

009

009

A02

A01

011

013

022

025

015

023

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 12: Lg Mcd112 Aou

2-5 2-6

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

RING FW MAYBE ADDEDFOR WOW FLUTTER WHEN NECESSARY

013

011009

009

003

008

015

022

023

024

016 017

018

019

020

007

A03

A00

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 13: Lg Mcd112 Aou

2-7 2-8

CD MECHANISM EXPLODED VIEW

416

151

159

165

164

417

166

417

167

416

177

175

172

170419

417

418 418190

189

188

A30

A32

A26

181

187

186

184

421

421

185

156

155

153

173

168

163

162

441

440

422

A35

417

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 14: Lg Mcd112 Aou

2-9 2-10

SPEAKER EXPLODED VIEWMODEL : MCS112F

850L850R

853 855

854

852

851

A80BA80LA80R

A80ALA80AR

856

WIRE80

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 15: Lg Mcd112 Aou

2-11 2-12 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

MEMOMEMO

Page 16: Lg Mcd112 Aou

2-13Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

PACKING ACCESSORY VIEW

Page 17: Lg Mcd112 Aou

2-14 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

MEMO

Page 18: Lg Mcd112 Aou

3-1Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

AUDIO ELECTRICAL TROUBLESHOOTING GUIDE

SECTION 3 AUDIO PART ELECTRICAL

1. POWER (SMPS)

POWER (SMPS)

OK

YES

YES

YES

Replace IC 901,902Check IC901, 902

Check the fuseF901

NONO

NO

YES

Check short ofP9701, P9702 line

Replace the fuse

Checkthe DC V of C905.

If DC V is over400V

NOCheck BD901, LF901, 902

Check theDC V of C981, C945.

If DC V is 6.1V

NOCheck short of P9702 line

YES

YES

Chcek theDC V of C950, C951

If DC V is in31.5V

NOCheck short of P9701 line

Chcek theDC V of C909, C903,

C921 If DC V is in 14~19Vand it is steady.

YES

Page 19: Lg Mcd112 Aou

3-2 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

2. P-SENS

P-SENS

YES

YES

Checkthe PIN6 of P9702

If DC V is over 5.6VCheck power circuit Trouble shooting

NO

OK

3. VKK CHECK

VKK check

YES

YES

Checkthe PIN3 of P9702

If DC V is over -28V ±2Check power circuit Trouble shooting

NO

OK

4. MICOM PART CHECK I

MICOM part check I

OK OK

YES

YES

Check P-SENS(P7904)_PIN6.

NO Refer toSMPS troubleshooting.

YES YESYES

Check bothend voltage of IC101

(KIA7042).

Checkif input voltage ofIC101(KIA7042) is

over 5V.

YES

NO Check theperiphery of IC101

(KIA7042).

NO

YES

Check if IC101(KIA7042) ofoutput voltage is over 4.3V.

Check voltage of IC10078KO/KF2_PIN1.

NO Replace IC101(KIA7042).

Page 20: Lg Mcd112 Aou

3-3Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

5. MICOM PART CHECK II

MICOM part check II

X101 : 32.768kHzX100 : 9.8304MHz

Check the operation.

CheckQ101_ emitter/collector

5V.Check Q102_base

0.6V HIGH.

Check if IC103_PIN8 and IC100_PIN19, 20, 59 are 5V.

NO NO

YES

YES

Check ifvoltage of P7904_PIN5

is 5.6V.

NO Refer toSMPS troubleshooting.

YES

YES

YES

OK

YES

Checkboth end voltage of

D101 YES

YES

Check D101.

NO Check if output ofD101(1SR35) is 5V.

YESYES

YES

YES

Check IC101.Q102_collector 0.6V LOW.

OK

Check if output of IC101(KIA7042) is over 4.3V.

OK

NOReplace IC101.

NOReplace D101.

YES

Check Q102.

OK

NOReplace Q102.

Page 21: Lg Mcd112 Aou

3-4 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

CheckIC100(78KOKF2)_

PIN 22, 24

OK

YES

YES

Refer tomicom troubleshooting

Check micomvoltage 5V.

PIN22DATA PIN24 CLK

NONO

YES

Replace micom.Check micom.NO

YES

OK

6. IC103(KS4CD21CS) CHECK

Page 22: Lg Mcd112 Aou

3-5Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

FLD display check

YES

YES

Replace P3702.Check eachPIN voltage.

NO

NO

YES

YES

OK

Replace IC301.Check IC301.NO

YES

Replace IC100FLD light on? Check IC100.NO

YES

YES

OK

Refer to SMPS

7. FLD DISPLAY CHECK

YES

YES

CheckP7904_PIN1, 2, 3 voltage

input.

NOCheck P3702 connection.

NO

If voltage is not 5V,check input and output

of D319(1SR35).

YES

Check P3702connection and power.

Pin1 : FL-22 Pin2 : FL+26Pin3 : VKK- over

26V.

YES

YES

YES

YES

OKOK

76 PIN - > DO - - >Check DATA in Check IC100.

NOIC100

75 PIN - > STB 77 PIN - > 4PIN DI

78 PIN - > 1PIN CLKCheck data output.

IC100 - >Check IC301

DATA communication.PIN PIN

75PIN - > 3PIN STB76PIN - > 2PIN D78PIN - > 1PIN

CLK

CheckIC301(PT6324) voltage.

Pin50 VKK : -26VPIN9.52 : +5V

Check if both end votageof F1, F2 are over 3.7V.

VKK : over 26V.

Page 23: Lg Mcd112 Aou

3-6 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

8. PWM MODULATION PART CHECK

PWM modulationpart check

YES

YES

YES

YES

P7905_PIN93.3V checking

Check IC604(PS9829)VDD PIN voltage(3, 7, 8,10, 22, 29, 39, 47, 56, 65,

72, 94).Check X601_PIN2 3.3V.

NO Refer toSMPS troubleshooting.

YES

YES

YES

YESCheck IC605_

PIN3 input and PIN2output.

CheckX601 12.288MHz

operation.

Check IC605_PIN8 3.3V.

Check IC605_PIN3 input

Check X6012.288MHz

NO

NO

IC604(PS9829) PIN86 CLK

input check

NO

Check FB614BEAD input, output and

voltage.

NO

Check X60112.288MHz.

Replace X601.

OK

NO

OK

YES

YES

NOReplace FB614

NO

Check IC605_PIN2 output

YES

OK

YES

OK

Replace IC605.NO

Check R680(470Ω) output.

Replace R680.NO

CheckIC604(PS9829) DATA

input.

Check each LINEregistor output.

NO

Check IC604(PS9829) DATA input.

78 PIN->DATA79 PIN->CLK

Check PWMmodulator output.

FL:75(+)74(-)FR:71(+)70(-)

NO

NO

CheckDVD ASS`Y(PS9829)

communication(P7403).

Refer toCD troubleshooting.

NO

CheckIC100(78KOKF2)21->PWM_CLK

22->PWM_DATA43->PWM_REST

output.

NO

YES

YES

OK

YES

OK

Check IC604(PS9829).OK

CheckLINE registor output.

DATA:R671, CLK:R670RST:R665

Replace R670, R671and R665

NO

NOReplace X601.

OK

YES

YES

YES

YES

Page 24: Lg Mcd112 Aou

3-7Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Power AMP part check

YES

Check each LINE registor output voltage.IC700 : R701, 702, 726, 727

NOCheck each

IC700, 701, 702, 703PIN1,17, 18, 19, 36 +12V

input.

Refer to SMPS troubleshooting.

YES

YES

YES

NOP7905_3PIN : +12V,PIN13, 14, 15 : 35V.

YES

Replace the coils

YES

NOCheck output line coil.

Check PWM modulator input.Each IC PIN4, 6, 14, 16

YES

Power IC700, 701, 702, 703PIN20, 27, 29, 34 output.

Check each IC700, 701, 702, 703PIN21, 26, 29, 34 input voltage.

OK

9. POWER AMP PART CHECK

Page 25: Lg Mcd112 Aou

3-8 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

10. AUX FUNCTION CHECK

AUX function check

Check µ-COM(IC301)_PIN83, 84 commucation.

NO NO

YES

Replace IC200

YES

YES

YES

CheckIC200(BU4052)_

PIN4, 11 inputwaveform.

CheckIC200(BU4052)_PIN16

VDD, PIN8 VSSpower.

Refer toSMPS troubleshooting.

NO NO

YES

Replace IC801OK

YES

YES

CheckIC801(MC4580)_PIN 2, 6

input waveform.

CheckIC801(MC4580)_PIN4

VSS, PIN8 VDDpower.

Check IC200(BU4052)_PIN3, 13 output waveform.

Check JK800 connection.

Page 26: Lg Mcd112 Aou

3-9Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

11. TUNER FUNCTION CHECK

TUNER function check

YES

Check IC200(BU4052)_PIN16 VDD, PIN8 VSS power.

NOCheck

IC200(BU4052)_PIN3, 13output waveform and IC601

(BU4052)_PIN2,15 inputwaveform.

Check TUNER module voltage(PIN2 : 9V).

YES

YES

YES

YES

NOCheck TUNERmodule(TU601) operation.

YES

Check IC801(MC4580)_PIN4 VSS, PIN8 VDD power.

YES

NOCheck IC801(MC4580)_PIN2, 6 input waveform.

Replace IC200.Replace IC200.

Replace IC801.

Check IC200(BU4052)_PIN1, 12 inputwaveform.

OK

Page 27: Lg Mcd112 Aou

3-10 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

12. TAPE FUNCTION CHECK

TAPE function check

YES

Check IC200(BU4052)_PIN16 VDD, PIN8 VSS power

YES

YES

YES

NOCheckIC200(BU4052)_PIN2, 15 input

waveform.

Check IC200(BU4052)_PIN16 VDD, PIN8 VSS power

YES

NOCheck IC801(MC4580)_PIN2, 6 input waveform.

YES

Replace IC200.Replace IC200.

Replace IC200.

Check IC200(BU4052)_PIN3, 13output waveform and IC601(BU4052)_

PIN2, 15 input waveform.

YES

TAPE PCB ASS`Y

OK

Page 28: Lg Mcd112 Aou

3-11Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

13. TAPE PLAY PART CHECK

TAPE PALY part check

Replace head wire and tapedeck mechanism.

NO NO

YES

YES

Check A deck head inputIC201_PIN32, 39 and B deckhead input IC201_PIN34, 37.

YES

YES

YES

YES

Check IC201_PIN5, 26 signal

output.

CheckIC201(HA12237)_PIN16

12V input.

Check A/Bdeck head input.

NO Refer toSMPS troubleshooting.

Check IC202_PIN10 "HIGH"NOCheck IC201_PIN14

mute operation.

Replace IC201.NO

YES

OK

Check IC201

YES

Replace IC202.NO

YES

OKOK

Check IC202.

Page 29: Lg Mcd112 Aou

3-12 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

14. TAPE REC PART CHECK

TAPE REC part check

Check IC100_PIN23 "HIGH"NO NO

YES

YES

Check IC201_PIN7, 24 record input.

Check P2203_PIN5, 3 inputand PIN8 erase input.

YES

YES

YES

YES

YES

Check L203_PIN2, 3oscillation.

CheckIC604(PS9829)_PIN49, 52

PWM output.

Check Q205(D1304)_base "HIGH".

Replace IC201.NO NOCheck IC201_

PIN10, 21 output.Check IC100_PIN23

"HIGH"

NO Refer to PWMmodulation troubleshooting.

OK

YES

Replace IC202.

YES

OK

OK

Page 30: Lg Mcd112 Aou

3-13Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

INTERNAL BLOCK DIAGRAM OF ICs

1. ES6838

SDRAM/ROMInterface

GPIO

+

Gateway

DMAController

HuffmanDecoder

ROM

DRAMInterface

RAM

VideoProcessor

TV-EncoderVDAC

HDMI I/F

DisplayOSD / SPUController

ScalerDeIntelacer16 K Cache

32-BitRISC

Processor

Audio ADC

Serial AudioInterface

Audio DAC

USB

DVDDescrambler

+Transport

ATAPI

Servo Controller / RF

8051µController

DSC

ECC

DigitalPLL

Page 31: Lg Mcd112 Aou

3-14 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

2. HA12237F

Page 32: Lg Mcd112 Aou

3-15Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

3. PS9829B

MBCK

SBCK

SLRCK

MLRCK

MSDIN[0:3]

SSDIN[0:3]

MIC_MCLK

DMIX_MCLK

OLRCK

OBCK

DMIX_SDOUT

PWM1_P/M

PWM2_P/M

PWM3_P/M

PWM4_P/M

PWM5_P/M

PWM6_P/M

PWM7_P/M

PWM8_P/M

PWM_HP_L_P/M

PWM_HP_R_P/M

PWM_SWL_P/M

EPD_ENA

OVERLOAD

MIC_BCK

MIC_LRCK

MIC_SDIN

SPI/I2C

SO/SDA

SCK/SCL

SI/I2C_AD0

/CS/I2C_AD2

EXT_MUTE

CLK

_IN

/RE

SE

T

PLL

_DV

DD

PLL

_DV

SS

PLL

_AV

DD

PLL

_AV

SS

DV

DD

DV

SS

IO_V

SS

IO_V

DD

Internal Controls

Internal Clock Internal Reset

HostInterface(I2C, SPI)

Mic,Input

Processor

InputMapper

SampleRate

Converter

Input&

OutputMUX

Serial AudioOutput

Interface

DownMixer

Mixer 4 BandEQ

BassManager

MainVolume

TrimVolume

SerialAudioOutput

Interface

PWMModulator

POPNRPower Supply

Out

put M

appe

r

PLL

Reset & Power Down

AutomaticGain

Limiter

4. PT6324

SG1/KS1

SG2/KS2

SG3/KS3

SG4/KS4

SG5/KS5

SG6/KS6

SG7/KS7

SG7/KS7

SG8/KS8

SG9/KS9

SG10/KS10

SG11/KS11

SG12/KS12

SG13/KS13

SG14/KS14

SG15KS15

SG16/KS16

SG17

SG18

SG19

SG20

SG21

SG22

SG23SG24

GR1

GR2

GR3

GR4

GR5

GR6

GR7

GR8

GR9

GR10

GR11

GR12

GR13

GR14

GR15

GR16

Segment Driver

Dimming Circuit

GridDriver

Control

DIN/DOUT

CLK

STB

OSC

LED1

K1 K2 VDD GND VEE

Timing Generator

Key Matrix Memory

LEDDriver

CSC

SerialData

Interface Display Memory

Page 33: Lg Mcd112 Aou

3-16 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

5. STR-S6757IF1905

4Vcc

StartStopBurst

OSC

Protectionlatch

DRIVEReg

Delay

BurstControl

BSD

OCP

GND

S

D

FB

FB

OCP/BD

SS/OLP

BD

Q

Q

S

S

R

R

MaxON

R Q

S

OLP

Reg&Iconst

Soft Start Counter

Bottom Selector

5

7

6

3

2

1

OVP

Page 34: Lg Mcd112 Aou

3-17Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

6. TAS5142

2nd-Order L-COutput Filter

for EachHalf-Bridge

BootstrapCapacitors

2-ChannelH-Bridge

BTL Mode

SystemMicrocontroller

OUT_A

OUT_B

OUT_C

OUT_D

BST_A

BST_B

BST_C

BST_D

RESET_ABRESET_CD

SystemPowerSupply

HardwireMode

Control

PVDD

GVDD (12 V)/VDD (12 V)

GND

HardwireOC Limit

M1

M3

PVDDPowerSupply

Decoupling

32 V

12 V

GND

VAC

PWM_A

PWM_C

PWM_D

PWM_B

VALID

M2

Left-Channel

Output

Right-Channel

Output

InputHúBridge 1

InputH-Bridge 2

GVDDVDD

VREGPower Supply

Decoupling

4

PV

DD

_A, B

, C, D

GN

D_A

, B, C

, D

GV

DD

_A, B

, C, D

4 4

VD

D

GN

D

VR

EG

AG

ND

OC

_AD

J

BootstrapCapacitors

2nd-Order L-COutput Filter

for EachHalf-Bridge

SD

OT

W

OutputH-Bridge 2

OutputH-Bridge 1

OTW

SD

TAS5508

Page 35: Lg Mcd112 Aou

3-18 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

7. U1739EJ2V1UD00/KF2_E

Port 0 P00 to P067

Port 1 P10 to P178

Port 2 P20 to P277

Port 3 P30 to P334

Port 4 P40 to P478

Port 5 P50 to P578

Port 6 P60 to P678

Port 7 P70 to P778

Port 12 P120 to P1245

Port 13 P130

Port 14 P140 to P1456

8

4

2

Key return

Reset control

On-chip debugNote 2

Multiplier &divider

Systemcontrol

Voltageregulator

REGC

XT2/EXCLKS/P124

XT1/P123

XT1/P121RESET

OCD0ANote 2/X1, OCD1ANote 2/P31

KR0/P70 toKR7/P77

OCD0BNote 2/X2, OCD1BNote 2/P32

X2/EXCLK/P122

Internal high-speedoscillator

8

Buzzer output BUZ/P141

Clock outputcontrol

Power on clear/low voltage

indicator

POC/LVIcontrol

PCL/P140

EXLVI/P120

VDD,EVDD

VSS,EVSS

FLMD0

16-bit timer/event counter 00

TO00/TI010/P01

TO01/TI011/P06

TI000/P00

TI001/P05

TOH0/P15

TOH1/P16

TI50/TO50/P17

TI51/TO51/P33

RxD0/P11

TxD0/P10

RxD6/P14

TxD6/P13

SI10/P11

SO10/P12

SI11/P03

SO11/P02

SCK11/P04

SCK11/P05

SIA0/P143

SOA0/P144

SCKA0/P142

STB0/P145

BUSY0/P141

EXSCL0/P62

SDA0/P61

SCL0/P60

AVREF

RxD6/P14 (LINSEL)

INTP0/P120

INTP1/P30 toINTP4/P33

INTP5/P16

INTP6/P140,INTP7/P141

AVSS

ANI0/P20 toANI7/P27

SCK10/P10

RxD6/P14 (LINSEL)

16-bit timer/event counter 01

8-bit timer H0

8-bit timer H1

Watchdog timer

78K/0CPUcore

Internalhigh-speed

RAM

Internalexpansion

RAM

Flashmemory

BANKNote 1

Watch timer

8-bit timerevent counter 50

8-bit timerevent counter 51

Serialinterface UART0

LINSEL

Serialinterface UART6

Serialinterface CSI10

Serialinterface CSI11

Serialinterface CSIA0

Serialinterface IIC0

A/D converter

Interruptcontrol

Internal low-speedoscillator

Page 36: Lg Mcd112 Aou

3-19 3-20

WIRING DIAGRAM

6P5P3P

CD PCB

2 CH SPK TERMINALAUX

JACK

TU

NE

RM

OD

UL

E3 CHANGER MD

MAIN PCB

DOUBLE DECKMECHANISM

30P

4P

8P3P 13P

29P

USB MIC H/P FRONT PCB

SMPS PCB

15P

4P

[Total CNT Q'ty : 14ea]

1. SMPS MAIN : 2ea2. MAIN DVD : 2ea3. MAIN FRONT : 1ea4. FRONT DVD : 1ea5. DVD MD : 5ea6. DECK MECHA. : 3ea

REDRED

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 37: Lg Mcd112 Aou

3-21 3-22

BLOCK DIAGRAMS1. SMPS BLOCK DIAGRAM

AC INPUT

ZNR & FILTER

TRANS

#1

AMPSwitchIC # 1

MAINSwitchIC # 2

TRANS

#2

FL1-FL2 (4.5V)

-12V

12V (78R12)

5V(P-SENS)

6.1V (KIA278R05) P9702

P9701

FEED BACK

AMP (+) 31.5V

3.5V (278R35)

-31. 5V(VKK)

RECTIFICATIONSMOOTHING

CIRCUIT

FEED BACK

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 38: Lg Mcd112 Aou

3-23 3-24

2. MAIN & FRONT BLOCK DIAGRAM

USB

FL +/-

FR +/-

SW +/-

FL

FR

SW

PS9830

PWMModulator

9830_RSTCLK/DATA

5142_RST

5142_S12.288MHz

9.8304MHz

D

DE

CK

AD

EC

K B

HA12237F

CassetteDeckASP

L/R, REC_L/RERASE

L/R

TR DRIVER

DE

CK

S/W

REC_MUTE, PB_MUTE, TAPE_A/B

SOL_A/B, MOTOR, REC_BIAS

HALL_A/B, LEAF_A/B

TU

NE

R M

OD

ULE

RDS_CLK / DATA, PLL_DO / CLK / CE[5]

PLL_DI, T_MUTE[2]

REC_L / R

DE

CK

_L /

R

AUX

4052_A / BTUNER_L / R

AUX_L / R

BA3308OPAMP (ALC)

H/P_L / R

EEPROMCLK/DATA

VFD_STB / DI / DO / CLK

FS

EQ

,WR

Q,C

D_

DO

,RX

[4]

AUDIO L / R

MCLK, LRCK, BCK, SD_OUT [7]

ADC_RST

D+ / D-,+5V/G

14.3178MHz

16.9344MHz

ND

PICK UPPICK UP

MOTORMOTOR

MDMD

AUX2

[4]

[4]

[4]

[3]

LC78692W

DSP IC

OTI6888 VER.A9

AUX2 _L/R

AM5810MOTORDRIVER

TX

, RX A,B,C,D,E,F

74HCT244BUFFER

RX

TX

EIG

HT

KIN

DS

EX

CE

PT

CD

IN

STDATA, STCK, STREQ[3]

FDO,TDO SL+/-, SP+/-

OP/CL

TA+/-, FA+/-

SLDO,SPDO

FSEQ,WRQ,CD_DO

H/P

MIC

CLK,DATA,+5V,GND

CLK

,DA

TA

MIC _SIG

MIC

_S

IG

[5]

[4]

[4]

[4]

[4]

[4]

[4]

[4]

78F0546

AUDIOMICOM

KS24C021EEPROM

PT6324FLT

DRIVER

FLTDISPLAY

TOUCH PAD

CY8C21484TOUCHPADDRIVER IC

TAS5152or

TAS5142

DigitalPowerAMP

LRCK,BCK,DATA0 [3]

BU4052

AK53582CH.ADC

AUDIOS/W

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 39: Lg Mcd112 Aou

3-25 3-26

SCHEMATIC DIAGRAMS1. SMPS SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

WHEN SERVICING THIS CHASSIS, UNDER NO CIR-CUMSTANCES SHOULD THE ORIGINAL DESIGN BEMODIFIED OR ALTERED WITHOUT PERMISSIONFROM THE LG CORPORATION. ALL COMPONENTSSHOULD BE REPLACED ONLY WITH TYPES IDENTI-CAL TO THOSE IN THE ORIGINAL CIRCUIT. SPECIALCOMPONENTS ARE SHADED ON THE SCHEMATIC

FOR EASY IDENTIFICATION. THIS CIRCUIT DIAGRAMMAY OCCASIONALLY DIFFER FROM THE ACTUALCIRCUIT USED. THIS WAY, IMPLEMENTATION OF THELATEST SAFETY AND PERFORMANCE IMPROVE-MENT CHANGES INTO THE SET IS NOT DELAYEDUNTIL THE NEW SERVICE LITERATURE IS PRINTED.

1. Shaded( ) parts are critical for safety. Replace onlywith specified part number.

2. Voltages are DC-measured with a digital voltmeter dur-ing Play mode.

IMPORTANT SAFETY NOTE :

Page 40: Lg Mcd112 Aou

3-27 3-28

2. MAIN SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 41: Lg Mcd112 Aou

3-29 3-30

3. AMP SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 42: Lg Mcd112 Aou

3-31 3-32

4. DECK SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 43: Lg Mcd112 Aou

3-33 3-34

5. FRONT SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 44: Lg Mcd112 Aou

3-35 3-36

6. KEY-L SCHEMATIC DIAGRAM 7. KEY-R SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 45: Lg Mcd112 Aou

3-37 3-38

PRINTED CIRCUIT BOARD DIAGRAMS1. MAIN P.C.BOARD(TOP VIEW)

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 46: Lg Mcd112 Aou

3-39 3-40

MAIN P.C.BOARD(BOTTOM VIEW)

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 47: Lg Mcd112 Aou

3-41 3-42

2. FRONT P.C.BOARD

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 48: Lg Mcd112 Aou

3-43 3-44

3. SMPS P.C.BOARD 4. KEY-L P.C.BOARD

5. KEY-R P.C.BOARD

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 49: Lg Mcd112 Aou

3-45 3-46 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

MEMO MEMO

Page 50: Lg Mcd112 Aou

4-1Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

CD ELECTRICAL TROUBLESHOOTING GUIDE

1. CD PART TROUBLESHOOTING

Turn on CD

YES

YES

NO

OPEN CLOSE check Connector check (PN803, PN804)NO

Check voltage CN806PIN1 : 12, PIN2 : 6.3V

NO

Check voltage PN805PIN22 : CLOSE, PIN23 : OPEN

YES

NO

“Reading”Display check

Connector check(PN802, PN803, PN804, CN806, PN814)

NO

Check micom interface circuit (PN805)(CE, BTL-MUTE, CD-IN, CD-OUT, CLK, WRQ, FSEQ)

YES

NO

Reading OK check Connector check (PN801,PN802)NO

YES

If PALY, AUDIOOUTPUT check

Check PN805 audio dataPIN10 : DA_LRCK (IC801 PIN60 LRSY)PIN11 : DA_BCK (IC801 PIN59 DATACLK)PIN12 : DA_DATA0 (IC801 PIN58 DATA)

NO

Check pick up movement

NO

Check AM5810FP (IC802)

NO

Check LC78692 (IC801)

OK

SECTION 4 CD PART ELECTRICAL

Page 51: Lg Mcd112 Aou

4-2 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

1-1. OPEN CLOSE NG

Connector locking check(PN803, PN804, PN814)

YES

YES

YES

YES

Check powersupply circuit (PN805, CN806)CN806 PIN1 : 12V, PIN2 : 6.3V

PN805 PIN8 : +5V_AD

Defective main power supplyNO

Check voltage change LO+, LO- OF IC803(PN805 PIN23 : OPEN, PIN22 : CLOSE)

Defective IC803

Defective mechanism

NO

Check voltagechange of OPEN CLOSE

IC803 INPUT voltage PIN6 : 12V, PIN7:6.3V (PN805 PIN2 : BTL_MUTE, 23 : OPEN,

22 : CLOSE)

Defective micomNO

Page 52: Lg Mcd112 Aou

4-3Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

1-2. “READING” DISPLAY CHECK (= ONLY “CD” DISPLAY)

Conector locking check(PN802, PN803, PN804, PN805, CN806)

YES

YES

YES

YES

YES

Check powersupply port (PN805, CN806)

CN806 PIN1 : 12V, PIN2 : 6.3V,PIN4 : 5V PN805PIN8 = 5V_AD

Defective connector or main power supply

Defective IC804

NO

Check micom interface circuit (PN805)PN805 PIN1, 3, 4, 15, 19, 26 signal check(1 : CE, 3 : DI, 4 : CLK, 15 : D0, 19 : RST,

18 : FSEQ, 26 : WRQ) PIN3 DI : From DSPto micom PIN15 DO : From micom to DSP

Check the waveform #1

Defective micom or connector

Defective IC804

NO

Check voltageThe PIN2 of IC804IC804 PIN2 : 3.3V

NO

Defective micom or connectorCheck reset

signal of PN805PN805 PIN19 : 5V

NO

Page 53: Lg Mcd112 Aou

4-4 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Connector locking check(PN801, PN802)

Is reading OK?

Defective pick up orIC802 or IC801Does sled move?

NONO Check PN802PIN3, 4 (SL+, SL-)

1-3. READING OK CHECK (= “NO DISC” DISPLAY)

Does lense move?(= UP & DOWN)

YES

A

YES

Defective pick up orIC802 or IC801

NONO Check PN801PIN13, 16 (FA+, FA-)

B

Defective pick up or IC802Does laser light?NONO

Check PN801 PIN10 (LD)

YES

C

Defective pick up orIC802 or IC801Does spindle rotate?

NONO Check PN802PIN3, 6 (SP+, SP-)

YES

D

Defective pick up orIC802 or IC801

NONO Check PN801PIN14, 15 (TA+, TA-)

E

Page 54: Lg Mcd112 Aou

4-5Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Defective IC801

DoesSL+ waveform

appear at (IC802 PIN13and PN802 PIN3)

waveform #2sled motor

wave

Does slinwaveform appear at

(IC802 PIN5)waveform #2

sled drivewave

NONO

1-4. READING OK CHECK #A (= “NO DISC” DISPLAY)

YES

YES

A

Defective IC802

NODefective PN802 connector

Defective pick up sled motor

Check PN802 connector line

YES

Defective IC801

DoesFA+ waveform

appear at (IC802 PIN16and PN801 PIN13)waveform #3 focus

coil drivewave

Doesfain-waveform

appear at (IC802 PIN25)waveform #3focus drive

wave

NONO

1-5. READING OK CHECK #B (= “NO DISC” DISPLAY)

YES

YES

B

Defective IC802

NODefective PN801 connector

Defective pick upfocus actuator

Check PN801 connector line

YES

Page 55: Lg Mcd112 Aou

4-6 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Defective IC804

Is ?V appliedto PIN10 of PN801laser supply voltage

check

Is 3.3Vapplied to

PIN30, 36, 39, 41, 61,68, 75 of IC801 RF IC

supply voltagecheck

NONO

1-6. READING OK CHECK #C (= “NO DISC” DISPLAY)

YES

YES

Defective IC801Is 2.3V

PIN18 (LDO) of IC801laser control voltage

check

NO

YES

C

Defective Q801 or D801

NODefective PN801 connector

Defective pick up laser part

Check PN801 connector line

YES

Page 56: Lg Mcd112 Aou

4-7Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Defective IC801

DoesSP+ waveform

appear at (IC802PIN11 and PN802 PIN5)

waveform #4 spindlemotor drive

wave

Doesspin waveform

appear at (IC802 PIN6)waveform #4spindle drive

wave

NONO

1-7. READING OK CHECK #D (= “NO DISC” DISPLAY)

YES

YES

D

Defective IC802

NODefective PN802 connector

Defective pick upspindle motor

Check PN802 connector line

YES

Page 57: Lg Mcd112 Aou

4-8 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Does FE, TE signalappear? (IC801

PIN10 : RFMON, PIN16 : TE)waveform #6

* REMON is FE

Defective IC801

DoesTA+ waveform

appear at (IC802 PIN17and PN801 PIN14)

waveform #5 trackingcoil drive

wave

Doestain - waveform

appear at (IC802 PIN22)waveform #5tracking drive

wave

NONO

1-8. READING OK CHECK #E (= “NO DISC” DISPLAY)

YES

YES

E

Defective IC802

Does ARF signal appear?

(IC801 PIN 2)waveform #6

NODefective pick up or IC801

Check PN802connector line

NODefective PN802 connector

YES

YES

NODefective pick up or IC801

Page 58: Lg Mcd112 Aou

4-9Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

2. USB PART TROUBLESHOOTING

Turn on USB

YES

NO

YES

Connector check(PN805, CN806, PN810 )

NO

Check power supply circuit (CN806)

Check micom interface circuit (PN805)PIN13 : RX (IC805 PIN49 : TXD)PIN14 : TX (IC805 PIN33 : RXD)

NO

NO

Check PN810 PIN2(D-), 3(D+)

Check OTI6888 (IC805)

Connector check (CN806)OK

YES

“Checking” or“USB” display check

NO

YES

Check PN810 1PIN : 5VReading OK checkNO

Check signal STCK, STREQ, STDATASTCK : IC805 PIN52, IC801 PIN55

STREQ : IC805 PIN53, IC801 PIN54STDATA : IC805 PIN54, IC801 PIN56

If PLAY, AUDIOOUTPUT check

NO

NO

Page 59: Lg Mcd112 Aou

4-10 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

WAVEFORMS OF MAJOR CHECK POINT

#1.MICOM INTERFACE WAVEFORM(PN805 PIN26, 19, 3, 15) during power on

PIN26 : WRQ

PIN19 : RESET

PIN3 : DI (IC801 PIN46 DATA OUT)

PIN15 : DO (IC801 PIN45 DATA IN)

#1.MICOM INTERFACE WAVEFORM(PN805 PIN26, 19, 3, 15) during normal play

PIN26 : WRQ

PIN19 : RESET

PIN3 : DI (IC801 PIN46 DATA OUT)

PIN15 : DO (IC801 PIN45 DATA IN)

#1.MICOM INTERFACE WAVEFORM(PN805 PIN4, 1, 18) during power on

PIN4 : CL

PIN1 : CE

PIN18 : FSEQ

#1.MICOM INTERFACE WAVEFORM(PN805 PIN4, 1, 18) during normal play

PIN4 : CL

PIN1 : CE

PIN18 : FSEQ

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4-11Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

#2.SLED DRIVE AND MOTOR WAVEFORM(IC802 PIN5, 13) when focus search

PIN5 : SLIN

PIN13 : SL+

#2.SLED DRIVE AND MOTOR WAVEFORM(IC802 PIN5, 13) during normal play

PIN5 : SLIN

PIN13 : SL+

#3.FOCUS DRIVE AND MOTOR WAVEFORM(IC802 PIN25, IC802 PIN16)

• When focus search failed or there is nodisc on tray

PIN25 : FAO

PIN16 : FA+

#3.FOCUS DRIVE AND MOTOR WAVEFORM(IC802 PIN25, IC802 PIN16)

• There is disc on tray and focus search success

PIN25 : FAO

PIN16 : FA+

Page 61: Lg Mcd112 Aou

4-12 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

#4.SPINDLE DRIVE AND MOTOR WAVEFORM(IC802 PIN6, 11) when TOC reading

PIN6 : SPINPIN11 : SP+

#5.TRACK DRIVE AND MOTOR WAVEFORM(IC802 PIN22, IC802 PIN17) during normal play

#6.RF, FOCUS AND TRACKING ERROR WAVEFORM(IC801 PIN2, 10, 16) during normal play

PIN2 : RFOUT

PIN 16 : TE

PIN10 : RFMON(FE)

PIN22 : TAO

PIN17 : TA+

Page 62: Lg Mcd112 Aou

4-13 4-14

SCHEMATIC DIAGRAMS1. CD SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 63: Lg Mcd112 Aou

4-15 4-16

2. USB SCHEMATIC DIAGRAM

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 64: Lg Mcd112 Aou

4-17 4-18

PRINTED CIRCUIT BOARD DIAGRAMCD P.C.BOARD(TOP VIEW) (BOTTOM VIEW)

Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

Page 65: Lg Mcd112 Aou

4-19 4-20 Copyright © 2009 LG Electronics. Inc. All right reserved.Only for training and service purposes

LGE Internal Use Only

MEMO MEMO