LG 21FS2ALX, 21FS2RG, 21FS2RL, 21FS2RLX, 21FS2RLX-TC Service Manual

COLOR TV

SERVICE MANUAL

CAUTION

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

CHASSIS : MC-049C

MODEL : 21FS2ALX/RG/RL/RLX

MODEL : 21FS2ALX/RG/RL/RLX-TC

- 2 -

CONTENTS

Contents...................................................................................................................2

Safety Precautions..............................................................................................3

Control Descriptions..........................................................................................4

Specifications........................................................................................................7

Adjustment Instructions .................................................................................8

Trouble Shooting.................................................................................................12

Printed circuit board.........................................................................................16

Block Diagram ......................................................................................................18

Exploded View....................................................................................................20

Exploded View Parts List ..............................................................................21

Replacement Parts List .................................................................................22

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

- 3 -

SAFETY PRECAUTIONS

Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in
the Schematic Diagram and Replacement Parts List.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to
prevent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.

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
as this protects the technician from accidents resulting in
personal injury from electrical shocks.

It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.

When replacing a high wattage resistor (Oxide Metal Film
Resistor, over 1W), keep the resistor 10mm away from PCB.

Keep wires away from high voltage or high temperature parts.

Due to high vacuum and large surface area of picture tube,
extreme care should be used in handling the Picture Tube.
Do not lift the Picture tube by it's Neck.

X-RAY Radiation

Warning:

To determine the presence of high voltage, use an accurate
high impedance HV meter.

Adjust brightness, color, contrast controls to minimum.
Measure the high voltage.
The meter reading should indicate

23.5

¡ 1.5KV: 14-19 inch, 26 ¡ 1.5KV: 19-21 inch,

29.0 ¡ 1.5KV: 25-29 inch, 30.0 ¡ 1.5KV: 32 inch
If the meter indication is out of tolerance, immediate service
and correction is required to prevent the possibility of
premature component failure.

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 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.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.

Leakage Current Hot Check (See below Figure)

Plug the AC cord directly into the AC outlet.

Do not use a line Isolation Transformer during this check.

Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC
voltmeter with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC
voltage measurements for each exposed metallic part. Any
voltage measured must not exceed 0.75 volt RMS which is
corresponds to 0.5mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.

Leakage Current Hot Check circuit

The source of X-RAY RADIATION in this TV receiver is the
High Voltage Section and the Picture Tube.
For continued X-RAY RADIATION protection, the
replacement tube must be the same type tube as specified in
the Replacement Parts List.

1.5 Kohm/10W

To Instrument’s
exposed
METALLIC PARTS

Good Earth Ground
such as WATER PIPE,
CONDUIT etc.

AC Volt-meter

IMPORTANT SAFETY NOTICE

0.15uF

All the functions can be controlled with the remote control handset.
Some functions can also be adjusted with the buttons on the front
panel of the set.

Remote control handset

Before you use the remote control handset, please install the bat­teries. See the next page.

1. POWER

switches the set on from standby or off to standby.

2. NUMBER BUTTONS

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

3. MENU (or INDEX)

selects a menu.
selects an index page in the teletext mode (only TELETEXT
models). (option)

4. EYE/*(option)

switches the eye function on or off.

5.

DD/ EE

(Programme Up/Down)

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

FF / GG

(Volume Up/Down)

adjusts the volume.
adjusts menu settings.

OK

accepts your selection or displays the current mode.

6. Q.VIEW

returns to the previously viewed programme.

7. TELETEXT BUTTONS (option)

These buttons are used for teletext.
For further details, see the ‘Teletext’ section.

8. PSM (Picture Status Memory)

recalls your preferred picture setting.

9. FAVOURITE

selects a favorite programme.

10. TURBO PICTURE / SOUND BUTTON (option)

selects Turbo picture and sound.

POWER MUTE

123

456

789

MENU/INDEX

TV/AV

TV

0

i

TEXT/MIX/ SIZE/ HOLD/

EYE/

Q.VIEW

LIST

I / II /

( )

PR

( )

PR

OK

VOLVOL

UPDATE/

PSM SSM/ SLEEP/ M

X

TIME/ REVEAL/

?

PICTURE SOUND

/

TURBO/

FAVOURITE

1

2

3
4

5

6

8

10

9

11

12
13

14

15
17

16

(With TELETEXT)

7

- 4 -

DESCRIPTION OF CONTROLS

- 5 -

POWER MUTE

1 2 3

4 5 6

7 8 9

MENU/INDEX

TV/AV

0

EYE/

Q.VIEW

LIST

I / II /

( )

PR

( )

PR

OK

VOLVOL

PSM SSM/ SLEEP

PICTURE SOUND

/

TURBO/

FAVOURITE

TV

1

2

3
4

5

6

8

10

9

11. MUTE

switches the sound on or off.

12. TV/AV

selects TV or AV mode.
switches the set on from standby.

13. I/II/*(option)

selects the language during dual language broadcast. (option)
selects the sound output.

14. LIST

displays the programme table.

15. SLEEP

sets the sleep timer.

16. SSM/*(Sound Status Memory) (option)

recalls your preferred sound setting.

17. SURROUND (ºº/*) (option)

selects surround sound.

*

: No function

COLOURED BUTTONS : These buttons are used for teletext (only

TELETEXT models) or programme edit.

11

12
13

14

15
17

16

(Without TELETEXT)

- 6 -

Front panel

Side panel

1. MAIN POWER (ON/OFF)

switches the set on or off.

2. POWER/STANDBY INDICATOR

illuminates brightly when the set is in standby mode.
dims when the set is switched on.

3. REMOTE CONTROL SENSOR

Note : Only use the supplied remote control handset. (When you use others, they’ll be not able to

function.)

4. MENU

selects a menu.

5. OK

accepts your selection or displays the current mode.

FF / GG

(Volume Up/Down)

adjusts the volume.
adjusts menu settings.

DD / EE

(Programme Up/Down)

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

6. AUDIO/VIDEO IN SOCKETS (AV2) (option)

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

7. HEADPHONE SOCKET (option)

Connect the headphone plug to this socket.

Note : Shown is a simplified representation of front or side panel. Here shown may be somewhat dif­ferent from your set.

VIDEO

L/MONO

R

AUDIO

AV2

7

6

21FS2 series

1 2 3 4 5

- 7 -

SPECIFICATIONS

Note : Specification and others are subject to change without notice for improvement.

F Scope

This specification can be applied to all the television related to
MC-049C Chassis.

F Test and Inspection Method

1) Capacity : Follow LG electronics TV testing Standard.

2) Another Required Standard

- EMI : Following CE Standard (EN55020, EN55013)

- Safety : Following CB Standard (EN55013)

F Requirement for Test

Testing for standard of each par must be followed in below
condition.

1) Temperature : 20

± 5°C

(But, CST must be tested 40

± 5°C . Humidity : 50%)

2) Relative Humidity : 65

± 10%

3) Power : Standard input Voltage (110-240V~, 50/60Hz)

4) Measurement must be performed after heat-run more than
20min.

5) Adjusting Standard for this chassis is followed a special
standard.

No

1

2

3

4
5
6
7

8

Item

Receiving System

Receiving Channel

Input Voltage

Market
Screen Size
Tuning System
Operating Environment

Storage Environment

Remark

For EU/ For Non EU

For EU/ For Non EU

NTSC-M (Multi - model)

Non EU

EU

Initial Model -> for EU

SUPER SLIM

200 PR. (OPTION)

Specification

1) PAL/SECAM BG

2) PAL/SECAM DK

3) PAL I/I

4) NTSC M

5) SECAM-L/L’

6) NTSC 4.43(AV)

1) VHF : E2 ~ E12
UHF : E21 ~ E69
CATV : S1 ~ S20
HYPER : S21 ~ S41

2) L/L’ : B,C,D

3) VHF : 02 ~ 13
UHF : 14~ 69
CATV : 02 ~ 71

110-240V~, 50/60Hz
240V~, 50Hz
EU,CIS, China, Asia, Africa
F 21”
FVS 100Program

1) Temp. : 0 ~ 45 deg

2) Humidity: 85% under

1) Temp. : -20 ~ 60 deg

2) Humidity: 85% under

F General Specification

1. Application Object

These instructions are applied to all of the color TV, MC-049C.

2. Notes

(1) Because this is not a hot chassis, it is not necessary to use

an isolation transformer. However, the use of isolation
transformer will help protect test instrument.

(2) Adjustment must be done in the correct order.But the

adjustment can be changed by consideration of mass
production.

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

25±5°C of temperature and 65±10% of relative humidity if
there is no specific designation.

(4) The input AC voltage of the receiver must keep rating

voltage in adjusting.

(5) The receiver must be operated for about 15 minutes prior

to the adjustment.

3. Focus adjustment

3.1. Preliminary steps

Tune the TV set to receive a digital pattern.
(SVC mode:Automatically mode change the STANDARD
mode)

3.2. Adjustment Method

1) Single Focus CPT

Adjust the upper Focus volume of FBT for the best focus of
horizontal line A,vertical line B.

4. Screen voltage adjustment

(1) Receive the PAL or SECAM(NTSC) signal into RF mode

regardless of channel.

(2) If you press the “ADJ”button in LINE SVC mode(IN-START

button),the LINE SVC mode changes to screen adjustment
mode.

(3) Adjust the screen volume of FBT jack,When width line is

seen turn the FBT screen volume at the position of
disappearance it.

(4) Press the TV/AV button to exit SVC mode.

5. White balance adjustment

NOTE : When adjusting white balance automatically,connect the

adjustment JIG in SVC mode.(When pressing ,MUTE
button on remote control, it changes to CPU OFF MODE
and screen displays “AUTO”.)

(1) Receive 100% white pattern.
(2) Adjust LOW Light status(4.5FL) of CUT R, CUT B at CUT

G:80.

(3) Adjust HIGH LIght status(35FL) of WDR R, WDR B at

WDR G:400.

(4) Repeat above step (2) and (3) for the best condition each

status of High Light and Low Light.

ADJUSTMENT INSTRUCTIONS

A

B

Menu

X
Y

Color Temperature

288
295

9000°K

266
273

13000°K

EU

N-EU

<Table 1> White Balance Color analyzer

Menu

CUT R
CUT G

CUT B
WDR R
WDR G
WDR B

LOW LIGHT

HIGH LIGHT

0 ~ 511
0 ~ 511
0 ~ 511
0 ~ 511
0 ~ 511
0 ~ 511

80
80

80
400
400
400

Range

DATA

<Table 2> White Balance Initial Data

Menu

<Fig 1. PAL Digital Pattern(EU05CH)>

2. White balance IIC Parameter

Program
Sub Add

Start Bit
Stop Bit

Offset

Polarity

EP_Rom_S

R_Amp

TWBeng_v049

1C8

12

4
0
1

9091

R_Cut

TWBeng_v049

1C3

12

4
0
1

8A8B

B_Amp

TWBeng_v049

1CA

12

4
0
1

9495

Program

Vcd Slave

TWBeng_v049

BCF0

Program

Eprom_Slave

TWBeng_v049ACSpeed1Delay

30

B_Cut

TWBeng_v049

1C5

12

4
0
1

8E8F

Speed/ Plus 1 1 1 1

<Table 3> White Balance Initial Data

1. IC

VCD IC

EP_ROM

VCT49xyi

24C16

Micronas

ST, ATMEL

0 A 0

Name

Maker Algorithm

- 8 -

6.Sub-Brightness adjustment

6-1. Preparation for Adjustment

(1) Tune the TV set to receive an Digital pattern(EU05CH).
(2) Deflection setting data adjustment is operate by SVC

communicator.

(3) Enter the Sub-Brightness mode by selection SERVICE1 on

SERVICE MENU after pressing LINE SVC MODE(IN­START KEY).

(4) Use the CH

D ,E key to select adjustment item.

(5) Use the VOL

F ,G key to increase/decrease data.

6.2 Adjustment

After authorizing a PAL signal, adjust up to the point which
divide one or two volume in Gray Scale of the bottom screen.

7.Deflection setting Data Adjustment

7.1 Adjustment preparation

(1) Tune the TV set to receive an Digital pattern(EU05CH).
(2) Deflection setting data adjustment is operate by SVC

communicator.

(3) Enter the deflection adjustment mode by selection

SERVICE1 on SERVICE MENU after pressing LINE SVC
MODE(IN-START KEY).

(4) Use the CH

D ,E key to select adjustment item.

(5) Use the VOL

F ,G key to increase/decrease data.

7.2 Adjustment

(1) After authorizing a PAL signal, adjust to N50ch .
(2) After adjusting a PAL signal, authorize and notify to

NTSC(US13ch), adjust NTSC if necessary.

*

After finishing deflection adjustment,press the ENTER button to

enter or exit in SVC mode.

< Term explanation>

(1) VL(Vertical Linearity) adjustment:

Adjust the top & bottom size of inner circle to be equal.

(2) VA (Vertical Amplitude) adjustment:

Adjust so that the circle of a digital circle pattern should be
located interval of 6~7mm from the effective screen of the
CPT.

(3) SC (S correction) adjustment:

Adjust so that all distance between each lattice width of
top/center/bottom are to be the same.

* Setting the CPT Default(Initial data) value like that, because
it is decide by CPT DY value

(4) VS (Vertical Shift) adjustment:

Adjust so that the geometric vertical center line is in accord
with vertical center line of CPT.

(5) HS(Horizontal Shift) adjustment:

Adjust so that the geometric horizontal center line is in
accord with horizontal center line of CPT.

(6) EW(Hor. Width) adjustment

Adjust until the outmost left and right lattice of received
pattern is accord with 25% of other lattice width.

(7) ET(Trapezoidal) adjustment

Adjust to make the length of top horizontal line same with it
of the bottom horizontal line.

(8) EP(Pin Cushion) adjustment

Adjust so that middle portion of the outermost left and right
vertical line look like parallel with vertical lines of the CPT.

(9) ANGLE adjustment

When you adjust the angle, adjust correctly raster of
left/right screen.

(10) Bow adjustment

After finished EP adjustment, adjust until symmetrized
upper and lower corner of the screen.

(11) UPCOR/LOCOR(Upper/Lower Corner) adjustment

After finished EP adjustment,adjust vertical line of left-top,
right-top, left-bottom, right-bottom of screen to the best
straight line.

8. How to inspect condition of a transmission
and reception in FM TRANSMITTER
MODEL.

- FM TRANSMITTER's efficiency inspections is executed to a

finished in a final inspection phase.

-FM TRANSMITTER is a function which receives voice-signal

by an exclusive remote control and earphone, transmits a
FM through transmitter of inner part in MICOM BOARD to TV
sound(MONITOR OUTPUT)

- If the received frequency which set up in OSD is being tuned

without using an exclusive remote control ,it is available to
receive in a general FM receiver.

(1) Execute in channel generating voice-signal.
(2) Select a transmitted frequency in MENU OSD.

MENU -> SOUND -> TRANSMITTER

-> Select frequency(87.7MHZ)

(3) A received frequency in an exclusive remote control or

received FM Radio is tuned by 87.7MHz which is same as
frequency in OSD.

(4) Check out whether a signal generating to MAIN SPEAKER

generates in earphone or receiver or not.

(5) There is no alternation and setting of adjusted DATA in the

process of inspecting FM TX.

- 9 -

<CAUTION> W/B Program “Twbeng_v049”

- W/B adjustment after Cutoff
: Instart -> adj. -> mute(cutoff)-> tv/av(wb)
Release key is EXIT key

- W/B adjustment
: Instart -> mute(cpuoff)
Release key is TV/AV key

Menu

VS
VA
VL
SC
HS

-512~511

-512~511

-512~511

-512~511
32~2047

150

-12

140

6

100

140

-12

140

6

123

Variable range

N50Hz(PAL)

FLAT 21”

N60Hz(NTSC)

FLAT 21”

<Table 4> Initial value of deflection setting