LG RZ-20LA60 Schematic

MONO

STEREO

ST

DUAL

LCD TV
SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : ML-012B

MODEL : RZ-20LA60

website:http://biz.LGservice.com

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

Jun.,2003

Printed in KoreaP/NO : 3828VD0154D

- 2 -

CONTENTS

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

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

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

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

TROUBLE SHOOTING............................................................................12

PRINTED CIRCUIT BOARD....................................................................13

BLOCK DIAGRAM...................................................................................16

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 Electronis 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 lsolation 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 1MΩ and 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 -

POWERMUTE

TV/AV I/II

LIST

PR

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

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 bat­teries. See the next page.

1. MUTE

switches the sound on or off.

2. TV/AV

selects TV or AV 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.

5.

DD / EE

(Programme Up/Down)

selects a programme or a menu item.
switches the set on from standby.

FF / GG (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 and selects a programme.

7. SSM (Sound Status Memory)

recalls your preferred sound setting.

8. SLEEP

sets the sleep timer.

1

9

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 menu.

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.

Battery installation

Note : To avoid damage from possible battery leakage, remove the

batteries if you do not plan to use the remote control handset for an
extended period of time.

POWERMUTE

TV/AV I/II

LIST

PR

PR

VOL

OK

1 2 3

4 5 6

7 8 9

SSM PSM

0

VOL

Q.VIEW MENU

SLEEP TEXT

UPDATE

TIME

SIZE MIX

HOLD

REVEAL

INDEX MODE

?

i

M

1

9

10

11

12

13

2

3
4

5

6

7

8

The remote control handset is pow­ered by two AAA/Alkaline type bat­teries. To load the batteries, turn
the remote control handset over
and open the battery compartment.
Install two batteries as indicated by
the polarity symbols ( and )
marked inside the compartment.

+

-

- 6 -

1. POWER (rr/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 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. REMOTE CONTROL SENSOR

8. LED (Light Emitting Diode) DISPLAY

illuminates brightly when the set is switched on.

: POWER/STANDBY indicator
: MONO indicator
: STEREO indicator

: DUAL indicator

9. HEADPHONE SOCKET

Connect the headphone plug to this socket.

10. AUDIO/VIDEO IN SOCKETS (AV3)

Connect the audio/video out sockets of exter­nal equipment to these sockets.

S-VIDEO/AUDIO IN SOCKETS (S-Video)

Connect the video out socket of an S-VIDEO
VCR to the S-VIDEO socket.
Connects the audio out sockets of the S­VIDEO VCR to the audio sockets as in AV3.

Side panel

MONO

STEREO

ST

DUAL

S-VIDEO VIDEO

AUDIO

R

AV3

L / MONO

PR

VOL

MENU

OK

POWER

TV
AV

/ I

6

5
4

3
2

1

7 8

9

10

MONO

STEREO

ST

DUAL

- 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 input voltage of the receiver must keep 100~220V,

50/60Hz in adjusting.

(5) The set must be operated for 30 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.

3. Component input mode adjustment

3-1. Required Test Equipment

(1) A pattern generator being in proportion to MSPG925LTH

(or 801F,SETTOP box)

(2) Adjustment Remote controller (SVC Remocon)

3-2. Preparation for Adjustment

(1) Perfome ‘Heat-run’ for more than 20 minutes in the White

Pattern.

(2) Connect the signal of Pattern generator with component

input Jack(YP

bPr

) of LCD TV.

3-3. YPbPrAdjustment

(1) Apply the DTV 1080i,color bar pattern by using

MSPG925LTH. Or apply DTV 1080i color bar pattern of
Pattern generator.

(2) In SVC menu mode,operate YP

bPr

adjustment by using

Volume + button.

ADJUSTMENT INSTRUCTION

4. Option1 data(200PR~A2 ST:1bit,SYS:2bit)

- 8 -

OPTION

Data

200PR

TEXT

I/II SV

TOP

A2 ST SYS

0
1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
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

SCART

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

OPTION

Data

200PR

TEXT

I/II SV

TOP

A2 ST SYS

32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
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

SCART

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1