Lg Rz-20la70 User manual

LCD TV

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS,

READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : ML-024D

MODEL : RZ-20LA70

website:http://biz.LGservice.com

e-mail:http://www.LGEservice.com/techsup.html

Oct.,2003

Printed in KoreaP/NO : 3828VD0168C

- 2 -

CONTENTS

CONTENTS .............................................................................................. 2

PRODUCT SAFETY ..................................................................................3

DESCRIPTION OF CONTROLS .............................................................. 4

ADJUSTMENT INSTRUCTION .................................................................7

TROUBLE SHOOTING............................................................................13

PRINTED CIRCUIT BOARD....................................................................14

BLOCK DIAGRAM...................................................................................17

EXPLODED VIEW .................................................................................. 18

EXPLODED VIEW PARTS LIST..............................................................19

REPLACEMENT PARTS LIST ............................................................... 20

SVC. Sheet .................................................................................................

- 3 -

PRODUCT SAFETY

IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audiovisual service

technicians. When servicing this product, under no circumstances should the

original design be modified or altered without permission from LG Electronics

Inc. All components should be replaced only with types identical to those in the

original circuit and their physical location, wiring, and lead dress must conform

to original layout upon completion of repairs. If any fuse (or Fusible Resistor) in

this TV receiver is blown, replace it only with the factory specified fuse type and

rating. When replacing a high wattage resistor (Oxide Metal Film Resistor, over

1W), keep the resistor 10mm away from PCB. Always keep wires away from

high voltage or high temperature parts.

Special components are also used to prevent shock and fire hazard.

These components are indicated by the letter “x” included in their component

designators and are required to maintain safe performance. No deviations are

allowed without prior approval by LG Electronics Inc. Service work should be

performed only after you are thoroughly familiar with these safety checks and

servicing guidelines.

Circuit diagrams may occasionally differ from the actual circuit used.

This way, implementation of the latest safety and performance improvement

changes into the set is not delayed until the new service literature is printed.

CAUTION: Do not attempt to modify this product in any way.

Never perform customized installations without manufacturer’s

approval.

Unauthorized modifications will not only void the warranty, but may

lead to property damage or user injury.

GENERAL GUIDANCE

An isolation Transformer should always be used during the servicing

of a receiver whose chassis is not isolated from the AC power line. Use a

transformer of adequate power rating to protect against personal injury from

electrical shocks. It will also protect the receiver and its components from being

damaged by accidental shorts of the circuitry that may be inadvertently

introduced during the service operation.

Before returning the receiver to the customer, always perform an AC leakage

current check on the exposed metallic parts of the cabinet, such as antennas,

terminals, etc., to be sure the set is safe to operate

without damage of electrical shock.

LEAKAGE CURRENT COLD CHECK

(ANTENNA COLD CHECK)

With the instrument’s AC plug removed from AC source, connect an electrical

jumper across the two AC plug prongs. Place the AC switch in the on position,

connect one lead of ohm-meter to the AC plug prongs tied together, and touch

other ohm-meter lead in turn to each exposed metallic parts such as antenna

terminals, phone jacks, etc. If the exposed metallic part has a return path to the

chassis, the measured resistance should be between 1MΩand 5.2MΩ. When

the exposed metal has no return path to the chassis the reading must be

infinite. Any other abnormality that exists must be corrected before

the receiver is returned to the customer.

ELECTROSTATICALLY SENSITIVE DEVICES

Some semiconductor (solid-state) devices can be damaged easily by static

electricity. Such components commonly are called Electrostatically Sensitive

(ES) Devices. Examples of typical ES 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 the

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 ES devices, place the

assembly on a conductive surface such as an ESD mat, to prevent

electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES 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 ES devices.

5. Do not use freon-propelled chemicals. These can generate electrical charge

sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package until

immediately before you are ready to install it. (Most replacement ES devices

are packaged with leads electrically shorted together by conductive foam,

aluminum foil, or comparable conductive material.)

7. Immediately before removing the protective material from the leads of a

replacement ES device, touch the protective material to the chassis or circuit

assembly into which the device will be installed.

Caution: Be sure no power is applied to the chassis or circuit, and observe

all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES

devices. (Otherwise, seemingly harmless motion, such as the brushing

together of your clothing or the lifting of your foot from a carpeted floor, can

generate static electricity sufficient to damage an ES device.)

DESCRIPTION OF CONTROLS

- 4 -

All the functions can be controlled with the remote control handset.

Some functions can also be adjusted with the buttons on the side

panel of the set.

Remote control handset

Before you use the remote control handset, please install the bat-

teries. See the next page.

1. MUTE

switches the sound on or off.

2. TV/AV

selects TV or AV monitor mode.

clears the menu from the screen.

switches the set on from standby.

3. LIST

displays the programme table.

4. Q.VIEW

returns to the previously viewed programme.

selects a favourite programme.

5. D / E(Programme Up/Down)

selects a programme or a menu item.

switches the set on from standby.

F / G (Volume Up/Down)

adjusts the volume.

adjusts menu settings.

OK

accepts your selection or displays the current mode.

6. NUMBER BUTTONS

switches the set on from standby or directly select a number.

7. SSM (Sound Status Memory)

recalls your preferred sound setting.

8. SLEEP

sets the sleep timer.

POWERMUTE

TV/AV I/II

LIST

PR

VOL OK

123

456

789

SSM PSM

0

VOL

Q.VIEW MENU

SLEEP TEXT

UPDATE

TIME

SIZE MIX

HOLD

REVEAL

INDEX MODE

?

i

M

19

10

11

12

13

2

3

4

5

6

7

8

- 5 -

9. POWER

switches the set on from standby or off to standby.

10. I/II

selects the language during dual language broadcast.

selects the sound output (option).

11. MENU

selects a me

12. PSM (Picture Status Memory)

recalls your preferred picture setting.

13. TELETEXT BUTTONS (option)

These buttons are used for teletext.

For further details, see the ‘Teletext’ section.

*: No function

COLOURED BUTTONS : These buttons are used for teletext (only

TELETEXT models) or programme edit.

POWERMUTE

TV/AV I/II

LIST

PR

VOL OK

123

456

789

SSM PSM

0

VOL

Q.VIEW MENU

SLEEP TEXT

UPDATE

TIME

SIZE MIX

HOLD

REVEAL

INDEX MODE

?

i

M

19

10

11

12

13

2

3

4

5

6

7

8

- 6 -

1. ON/OFF (O/I)

switches the set on from standby or off to

standby.

Note : Power line lives even when the power

is off.

2. TV/AV

selects TV or AV monitor mode.

clears the menu from the screen.

switches the set on from standby.

3. MENU

selects a menu.

4. OK

accepts your selection or displays the current

mode.

5. FF/ GG(Volume Up/Down)

adjusts the volume.

adjusts menu settings.

6. DD/ EE(Programme Up/Down)

selects a programme or a menu item.

switches the set on from standby.

7. POWER/STANDBY INDICATOR (O)

illuminates red in standby mode.

illuminates green when the set is switched on.

8. REMOTE CONTROL SENSOR

9. HEADPHONE SOCKET

Connect the headphone plug to this socket.

10. AUDIO/VIDEO IN SOCKETS (AV2)

Connect the audio/video out sockets of exter-

nal equipment to these sockets.

S-VIDEO/AUDIO IN SOCKETS (SAV)

Connect the video out socket of an S-VIDEO

VCR to the S-VIDEO socket.

Connects the audio out sockets of the S-

VIDEO VCR to the audio sockets as in AV2.

Back panel

Side panel

RL

VIDEO

AV2

AUDIO

(MONO)

H/P S-VIDEO

TV/AVMENUOKVOLPR /I

ON/OFF

7

8

9 10

6

5

4

3

2

1

•RZ- 20LA70 series

- 7 -

1. Application Object

This instruction is for the application to the LCD TV.

2. Notes

(1) This set uses an adapter, so connect the adapter and the

set correctly before adjustment.

(2) The adjustment must be performed under the correct

sequence.

(3) The adjustment must be performed in the circumstance of

25!5cC of temperature and 65!10% of relative humidity if

there is no specific designation.

(4) The set must be operated for 15 minutes preliminarily

before adjustment if there is no specific designation.

[‘Heat Run’ must be performed with the full white signal or TV

noise signal in the internal part of the set.

[ The time for ‘Heat Run’ can be changed owing to production

plan.

[ Line Test condition (TV): standard color signal 65!1dBuV

ADJUSTMENT INSTRUCTION

- 8 -

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

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OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

32

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SCART

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1

4. Option 1 data setting (200PR ~ A2 ST:1bit, SYS:2bit composition)

- 9 -

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

64

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2

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0

1

2

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0

1

2

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0

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2

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0

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2

3

0

1

2

3

0

1

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3

0

1

2

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0

1

SCART

0

1

0

1

0

1

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

110

111

112

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0

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0

1

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1

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1

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SCART

1

0

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0

1

- 10 -

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

156

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1

0

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0

1

0

1

0

1

0

1

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

2

3

0

1

SCART

1

0

1

0

1

0

1

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

202

203

204

205

206

207

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211

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01

1

0

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1

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1

2

3

0

1

2

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0

1

2

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2

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0

1

2

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0

1

2

3

0

1

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SCART

1

0

1

0

1

0

- 11 -

OPTION

Data 200PR

TEXT

I/II SV TOP A2 ST SYS

248

249

250

251

252

253

254

255

1

0

1

0

1

2

3

0

1

2

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SCART

1

5. Option2 data(ACMS~BBACK:1bit,LANG:3bit)

OPTION

Data ACMS

VOL

BBACK LANG

0

1

2

3

4

5

6

7

8

9

10

11

12

13

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0

1

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0

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63

OPTION

Data ACMS

VOL

BBACK LANG

1

0

1

0

1

0

1

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

- 12 -

6. Option3 data(IIC AFT~CH+AU:1bit)

OPTION

Data HiDEV

TSS

IIC T MONO CH+AUS

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

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25

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28

29

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31

0

1

0

1

0

1

0

1

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1

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1

0

1

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0

1

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1

0

1

0

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0

1

0

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0

1

0

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0

1

0

1

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1

0

1

0

1

- 13 -

1 No sound Defective Reset IC of IC604. 1) Check volume and speaker.

- Speaker Defective MSP3410G of IC601. - Sound comes out only when being inputted into Audio

- Earphone Defective B+(8V) of IC604. L/R.

2) Check after replacing IC603.

3) Replace IC601.

4) Check and replace B+ of IC604.

2 Video color beat noise Earphone shield case being touched.

Check the mould of shield and SJ209, Replace shield case.

Soldering IC501. 1) Check signal of Video input.

2) Check signal of R.G.B output.

3) Re-soldering

1 No screen Input error of inverter connector 1) Bend the pin legs of

P802B

connector -> recheck them

2) Check and repair IC805 SI4925.

P1 and Pin 50 connector 1) Check and fix P1 connector

being slipped out

Cracked components and 1)Check and repair tuner board and main board

soldering at tuner board 2)Solder Q403

2 Dark screen 1) Defective LCD lamp 1) Replace the inverter

2) Defective inverter 2) Replace the LCD lamp

3) Input error of inverter connector 3) Check the connector input.

TROUBLE SHOOTING

1. General Features

No. Symptom Cause Check Point

Check Point

2. TV and external input

No. Symptom Cause

- 14 -

PRINTED CIRCUIT BOARD

MAIN(TOP)

- 15 -

MAIN(BOTTOM)

- 16 -

POWER

CONTROL

BLOCK DIAGRAM

- 17 -

- 18 -

EXPLODED VIEW

400

310

120

560

530

250

340

360

380

370

330

350

210

300

112

520

230

430

- 19 -

112 6306V20002A LCD MODULE,V201V1-T01 VGA CHIMEI TFT COLOR

120 6400GKTX01A SPEAKER,FULLRANGE F1527C-6428 K-TONE 8OHM 7/12W 83DB OTHERS

210 4811V00076A BRACKET ASSEMBLY,REAR AV RZ-20LA70 ML024D .

230 4950V00192A METAL,SHIELD SBHG ML024

4950V00192C METAL,SHIELD SBHG 20LA70 C/SKD

250 4950V00188A METAL,FRAME SBHG FOR CMO MODULE

4950V00188B METAL,FRAME SBHG C/SKD

300 3091V00587A CABINET ASSEMBLY,RZ-20LA70 NON NON ML024D SET,LGEIS

3091V00587C CABINET ASSEMBLY,RZ-20LA70 STEREO ML024D C/SKD

310 5020V00871A BUTTON,CONTROL RZ-20LA70 ABS 8KEY .

330 4950V00157E METAL,HINGE ASSY NON 20LA70

340 4810V00767A BRACKET,STAND 20LA60 ML012B NON HINGE FRONT

350 4810V00768A BRACKET,STAND 20LA60 ML012B NON HINGE COVER

360 4810V00924A BRACKET,STAND RZ-20LA70 NON ABS .

370 4950V00193A METAL,STAND SPCC(CR) BASE(20LA70)

380 4950V00194A METAL,STAND SPCC(CR) SUPPORTER(LA70)

400 3809V00407A BACK COVER ASSEMBLY,RZ-20LA70 NON (STUH),LGEIS

3809V00407C BACK COVER ASSEMBLY,RZ-20LA70 1SCART 3850VC0002F(LGERU)

3809V00407D BACK COVER ASSEMBLY,RZ-20LA70 1SCART C/SKD

430 3550V00383A COVER,REAR AV RZ-20LA70 HIPS 60HR .

520 6871VMMR05A PWB(PCB) ASSEMBLY,MAIN ML-024D RZ-20LA70

530 6871VSMQ31A PWB(PCB) ASSEMBLY,SUB CONT ML024D 70TOOL CONTROL ASSY

560 6871VSMQ30A PWB(PCB) ASSEMBLY,SUB POWER ML024D 70TOOL POWER ASSY

EXPLODED VIEW PARTS LIST

No. PART NO. DESCRIPTION

REPLACEMENT PARTS LIST

LOCA. NO PART NO DESCRIPTION

Q404

Q405

Q406

Q407

Q501

Q502

Q510

Q551

Q602

Q603

Q701

Q703

Q706

Q801

Q802

R1211

R1212

D100

D1101

D1102

D1103

D1104

D1105

D1106

D701

D702

D704

D706

D707

D710

D711

ZD1101

ZD1102

ZD202

ZD203

ZD400

ZD701

ZD704

C10

C101

C1101

0TR387500AA

0TR150400BA

0TR387500AA

0TR322709AA

0TR387500AA

0TR150400BA

0TF492509AA

0DD181009AB

0DRSA00150A

0DD100009AM

0DR060009AA

0DRSD00091A

0DR340009AA

0DZRM00178A

0DZ330009BA

0DZ910009AJ

0DZ110009AD

0CE227DF618

0CE107BF618

0CC15003G06

CHIP 2SC3875S(ALY) KEC

CHIP 2SA1504S(ASY) KEC

CHIP 2SC3875S(ALY) KEC

KTC3227-Y,TP(KTC1627A),KEC

CHIP 2SC3875S(ALY) KEC

CHIP 2SA1504S(ASY) KEC

SI4925DY TP TEMIC 30V 6.1A SO-8

KDS181 TP KEC - 85V - - - 300MA

RBV-406 BK USC 600V 4A 80VA .SEC

EU1ZV(1) TP SANKEN

TVR06J TP DO41 600V 0.6A - - -

SF20JC10 ST FTO220(4115) 100V 20A

MBRS340 TP - 40V 3A 80A - 2MA

UDZS TE-17 5.1B 0.2W 5.1V 5MA -PF

ZENER HZT33 TAPING

MTZJ9.1B TP DO34 0.5W 9.1V 5UA -

MTZJ11B TP DO34 - 11V 5UA -

220UF STD 16V M FL TP5

100UF KME 16V M FL TP5

15PF D 3KV 10%,-10% SL FMTW

LOCA. NO PART NO DESCRIPTION

IC100

IC101

IC102

IC1101

IC1110

IC1111

IC1112

IC1121

IC1122

IC351

IC352

IC501

IC502

IC601

IC603

IC604

IC650

IC701

IC702

PC1

PC2

Q101

Q102

IC1102

IC1103

IC1104

IC1105

IC1223

IC1224

IC2

Q1

Q100

Q1101

Q1102

Q1103

Q1200

Q200

Q202

Q353

Q402

Q403

0ISM555000B

0IAL241610B

0IFA752700A

0IMCRO2001A

0IMCRRH005A

0IMCRMZ001A

0IMCRFA010A

0ISO204000A

0IMCRTW001B

0ICTMMO005A

0IMCRMN011D

0IKE704200J

0IMCRFA009A

0IMCRTI022D

0IPMGSK012A

0IMCRFA007A

0ILI817000G

0IFA270000A

0TFFC80044A

0TF492509AA

0TR387500AA

0TR150400BA

0TR387500AA

0TR150400BA

SDA555XFL 52DIP ST FLASH MEMORY

AT24C16A-10PI-2.7 8PIN DIP ST EEPROM

KA75270Z 3 TP RE-SET IC MC-007

OZ960S O2MICRO 20P SSOP R/TP

UM6K1N ROHM 6P SOT363 R/TP 30V 0.1A

MP1583DN 8P TSOP R/TP DC-DC

KA7809R, FAIRCHILD 2P D-PAK, R/TP

CXA2040AQ 32P,QFP BK IIC BUS VIDEO

LG8801-H TECHWELL 160P QPFD TRAY

SC786109DWR2 MOTOROLA SOIC 16P

MSP3410G QA B8 V3 MICRONAS 80P QFP

KIA7042AF SOT-89 TP 4.2V VOLTAGE

KA78M08RTM, FAIRCHILD 2P D-PAK

TPA3004D2 48P PQFP TRAY 9WSTEREO

STR-W6853P SANKEN 6P T0-220 ST

KA431Z FAIRCHILD 3DIP,TO-92 TP

LTV817M-VB 4P,DIP BK PHOTO COUPLER

2N7000TA TO-92, 3P TP LEVEL SHIFT

FDS8958A FAIRCHILD R/TP SO-8 30V 7A

SI4925DY TP TEMIC 30V 6.1A SO-8

CHIP 2SC3875S(ALY) KEC

CHIP 2SA1504S(ASY) KEC

CHIP 2SC3875S(ALY) KEC

CHIP 2SA1504S(ASY) KEC

IC

TRANSISTOR

- 20 -

DIODE

CAPACITOR

For Capacitor & Resistors, the

charactors at 2nd and 3rd digit

in the P/No. means as follows;

CC, CX, CK, CN : Ceramic

CQ : Polyestor

CE : Electrolytic

RD : Carbon Film

RS : Metal Oxide Film

RN : Metal Film

RF : Fusible

LG RZ-20LA70 User manual

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