LG 21FX5REE, 21FX5RG, 21FX5RGP Service Manual

COLOR TV

SERVICE MANUAL

CAUTION

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

CHASSIS : MC-049B

MODEL : 21FX5REE/RG/RGP

MODEL :

21FX5REE/RG/RGP-TB

website:http://biz.LGservice.com

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

- 2 -

CONTENTS

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

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

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

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

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

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

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

Block Diagram......................................................................................................19

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.

IMPORTANT SAFETY NOTICE

0.15uF

AC Volt-meter

Good Earth Ground such as WATER PIPE,

To Instrument's exposed METALLIC PARTS

CONDUIT etc.

1.5 Kohm/10W

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DESCRIPTION OF CONTROLS

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.

D/ E

(Programme Up/Down)

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

F / G

(Volume Up/Down)

adjusts the volume. adjusts menu settings.

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.

11. MUTE

switches the sound on or off.

12. TV/AV

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

VOL

PLAY

P/STILL STOP

REC

REW

I/II/ SSM/ LIST

PSM

PIP

FAVOURITE

Q.VIEW

SLEEP

MIX

TIME

SWAP

INPUT

REVEAL MODE

SIZE

STILL

POSITION

9/4PIP

TV/AV

PICTURE

SOUND

2 3

5 6

8 9

POWER

MUTE

EYE/

T U R B O /

TEXT/

( )

13 15

- 5 -

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/

(option) (Sound Status Memory)

recalls your preferred sound setting.

17. SURROUND (

ºº

) (option)

selects surround sound.

18. VCR BUTTONS

control a LG video cassette recorder.

19. PIP BUTTONS (option) PIP

switches the sub picture on or off.

PR +/-

selects a programme for the sub picture.

SWAP

alternates between main and sub picture.

INPUT

selects the input mode for the sub picture.

SIZE

adjusts the sub picture size.

STILL

freezes motion of the sub picture.

POSITION

relocates the sub picture in clockwise direction.

9/4 PIP

switches on or off the 9 or 4 sub pictures.

: No function

COLOURED BUTTONS : These buttons are used for teletext (only

TELETEXT models) or programme edit.

(Without TELETEXT / PIP)

POWER MUTE

123

456

789

MENU/INDEX

TV/AV

EYE/

Q.VIEW

LIST

I / II /

( )

VOLVOL

PSM SSM/ SLEEP

PICTURE SOUND

TURBO/

FAVOURITE

3 4

12 13

15 17

TEXT/MIX/ SIZE/ HOLD/

Q.VIEW

LIST

UPDATE/

PSM SSM/ SLEEP/ M

TIME/ REVEAL/

PICTURE SOUND

TURBO/

FAVOURITE

(With TELETEXT / Without PIP)

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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.

8. EYE (option)

adjusts picture according to the surrounding conditions.

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

21FX4R series

17/21FX5R series

Front panel

Side panel

VIDEO

L/MONO

AUDIO

AV2

2 3

- 7 -

SPECIFICATIONS

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

V Scope

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

V 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)

V Requirement for Test

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

1) Temperature : 20

± 5°C

(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.

4 5 6 7

Item

Receiving System

Receiving Channel

Input Voltage

Market Screen Size Tuning System Operating Environment

Storage Environment

Remark

For EU/ For Non EU

NTSC-M (Multi - model)

Non EU

FLAT / CONVENTIONAL

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 14” ~ 21” FVS 100Program

1) Temp. : 0 ~ 45 deg

2) Humidity: 85% under

1) Temp. : -20 ~ 60 deg

2) Humidity: 85% under

V General Specification

1. Application Object

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

2. Notes

(1) Because this is cold chassis, it is not necessary to use an

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

(2) But, operate it using a transformer between the power

supply line and chassis input to prevent electric shock and

to protect the test instrument. (3) All adjustments must be done in correct sequence. (4) However, for the better productivity, it can be changed in

pre-permitted range. (5) Environment conditions : If not specified, it must be done in

following conditions.

1) Temperature : 25±5°C

2) Humidity : 65±10%

(6) Power supply of a SET which is adjusted is (100-240V~)

±10%, 50~60 Hz (7) If not specified, the receiver must be operated for more

than 20 minutes period to the adjustment. (8) Signal : Receive the standard color signal (65dB±1dB uV)

LG standard signal means the digital pattern,EU 05 CH(PAL)

3. Focus voltage adjustment

(1) Receive the LG standard pattern

(digital pattern, PAL : Fig 1 & NTSC : Fig2) (2) Set the picture condition on ‘STANDARD’ mode. (3) Adjust the Focus volume of FBT for the best focus of

horizontal line A, vertical line B.

4. Purity & Convergence adjustment

4.1. Purity adjustment

(1) Preparation

1) Receive the RED Raster Pattern for purity adjustment. (11CH)

2) Demagnetize the CPT and cabinet with a degaussing coil.

(2) Adjustment

1) Pre-adjust the static convergence(STC) with 4 and 6pole magnet.

2) Push the DY all way to the CPT panel.

3) Turn the purity magnet (2-pole magnet) so that the green portion of left side and the blue portion of right side have same portion.

4) Pull the DY slowly and fix it when the whole screen become red.

4.2. Convergence adjustment

(1) Preparation

1) Receive the Cross Hatch pattern for convergence adjustment. (09CH)

2) Let the contrast at the adequate luminance level.

(2) Adjustment

1) Converge the RED vertical line and BLUE vertical line in the same line by changing the angle between the 2 tabs of the 4 pole magnet.

2) Converge the RED horizontal line and BLUE horizontal line in the same line by turning the 2 tabs of the 4pole magnet. This time, do not changing the angle between the 2 tabs.

3) Converge the R,G,B vertical line in the same line by changing the angle between the 2 tabs of the 6pole magnet.

4) Converge the R,G,B horizontal line in the same line by turning the 2 tabs of the 6pole magnet. This time, do not change the angle between the 2 tabs.

5. Screen voltage & White balance adjustment

Screen adjustment mode:INSTART for line SVC MODE then ADJ. Vary screen volume of the FBT till horizontal line appear and stop to the point that it starts to disappear.

5-1. 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.

5-2. White balance adjustment

- Prior to this adjustment, the Screen Voltage adjustment must be finished.

(1) Necessary Instrument

1) Auto White Balance Meter

2) Color Analyzer (CA-100)

3) Factory SVC Remote control

(2) Adjustment

1) Make the picture luminance 35±10 Ft-L by changing the “CONTRAST” and “BRIGHTNESS”.

- 8 -

ADJUSTMENT INSTRUCTIONS

2) Enter the white balance adjust mode with a factory remote control.

3) Adjust HIGh Light status of WDR R, WDR B at WDR G.

4) Make the Picture luminance 4.5±1 Ft-L by changing the ‘contrast’ and ‘brightness’.

5) Adjust LOW Light status of CUT R, CUT B at CUT G.

6) Repeat 1) ~ 5) until both low and high have same color temperature with below.

* Note: When adjusting white balance automatically, connect the

adjustment JIG in SVC mode. (When pressing IN-START, MUTE button on remote control for adjustment orderly, it changes to SVC mode and screen displays SVC.)

* White balance auto adjustment- Jig initial setting data

2. White balance IIC Parameter

6. SUB Brightness adjustment

Receiving signal : Digital pattern (PAL : EU05CH)

1) In the LINE SVC MODE(IN-START key), select SERVICE11 change S-BRI by VOL ± key

2) Change S-BRI data till 2~3 Gray scale of the pattern can be discerned.

7. Deflection setting Data Adjustment

7.1 preparation

(1) At adjustment mode(IN-START button on remote control of

adjustment), change to LINE SVC 2 mode to adjust the deflection.

(2) Press Channel UP/DOWN button for desirous function

adjustment. (3) Press Volume UP/DOWn button to adjust the data (4) Tune the TV set receive a digital pattern.

7.2 Adjustment

<Note>

First, adjust deflection at 50Hz of PAL signal. Then, adjust deflection at 60Hz of NTSC signal (RT) In case of PAL only model, adjust deflection at 50Hz of PAL signal. Store the deflection adjustment data in EEPROM by using ENTER button before adjusting PIP position. After finishing deflection adjustment, press the ENTER button to enter or exit PIP position.

(1) VA (Vertical Amplitude)

Adjust so that the circle of a digital circle pattern may be

located within the effective screen of the CPT. (2) VL(Vertical Linearity)

Adjust so that the boundary line between upper and lower

half is in accord with geometric horizontal center of the

CPT. (3) SC(S-Correction)

Adjust so that all distance between each horizontal lines

are to be the same. (4) VS (Vertical Shift)

Adjust so that the horizontal center line of a digital circle

pattern is in accord with geometric horizontal center of the

CPT. (5) HS(Horizontal Shift)

Adjust so that the vertical center line of a digital circle

pattern is in accord with geometric vertical center of the

CPT. (6) EW(Horizontal Shift)

Adjust so that a digital circle pattern looks like exact circle. (7) ET(East-west Trapezium)

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

of the bottom horizontal line. (8) EP(East-west Parabola)

Adjust so that middle portion of the outermost left and right

vertical line looks like parallel with vertical lines of th CPT. (9) ES(East-west Symmetric)

Adjust until the upper and lower corner of the screen

symmetric. (10) EC(East-west Corner)

After completing the EP adjustment, adjust so that the

corner vertical line to be straight..

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AXIS

X Y

Color Temperature

288 295

9000°K

266 273

13000°K

N-EU

<Table 1> White Balance Color axis

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

60 60

60 400 400 400

Range

DATA

<Table 2> White Balance Initial Data

<Table 3> White Balance Initial Data

1. IC

VCD IC

EP_ROM

VCT49xyi

24C16

Micronas

ST, ATMEL

0 A 0

Name

Maker Algorithm

Speed/ Plus 1 1 1 1

Program Sub Add Start Bit Stop Bit

Offset

Polarity

EP_Rom_S

R_Amp

TWBeng_v049

1C8

4 0 1

9091

R_Cut

TWBeng_v049

1C3

4 0 1

8A8B

B_Amp

TWBeng_v049

1CA

4 0 1

9495

Program

Vcd Slave

TWBeng_v049

BCF0

Program

Eprom_Slave

TWBeng_v049ACSpeed1Delay

B_Cut

TWBeng_v049

1C5

4 0 1

8E8F

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