LG 25FB7RLE Service Manual

COLOR TV

SERVICE MANUAL

CAUTION

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

CHASSIS : CW62C

MODEL : 25FB7RLE

MODEL : 25FB7RLE-T1

website:http://biz.LGservice.com

Oct, 2007

Printed in ChinaP/NO : MFL37794424

Internal Use Only

- 2 -

CONTENTS

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

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

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

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

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

Trouble Shooting ................................................................................................16

Printed circuit board........................................................................................20

Block Diagram .....................................................................................................22

Exploded View....................................................................................................24

Exploded View Parts List .............................................................................25

Replacement Parts List .................................................................................26

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

LGE Internal Use Only

- 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

LGE Internal Use Only

To Instrument’s exposed METALLIC PARTS

AC Volt-meter

Good Earth Ground such as WATER PIPE, CONDUIT etc.

1.5 Kohm/10W

- 4 -

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

selects a menu.

4.

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.

OK

accepts your selection or displays the current mode.

5. TELETEXT BUTTONS (option)

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

6.

SLEEP

sets the sleep timer.

7. 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.

(With TELETEXT / PIP)

0

PR

VOL

OK

UPDATE/ HOLD/

(With TELETEXT / Without PIP)

5

1 2 3 4

5

6

7

8

9

0

PR

VOL

OK

1

2

3

4

6

5

7

12

8

11

14

13

9

10

LGE Internal Use Only

- 5 -

8. FAVOURITE

selects a favorite programme.

9.

EYE/*(option)

switches the eye function on or off.

10. MUTE

switches the sound on or off.

11. TV/AV

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

12.

I/II/

*

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

13. Q.VIEW (or YELLOW)

returns to the previously viewed programme.

14.

LIST (or BLUE)

displays the programme table.

*

: No function

COLOURED BUTTONS : These buttons are used for teletext (only

TELETEXT models) or programme edit.

(Without TELETEXT / PIP)

1 2 3 4

5

6

7

8

9

0

PR

VOL

OK

(With PIP / Without TELETEXT)

7

Q.VIEW LIST

4

1

3

2

8

12

13

11

14

6

9

10

LGE Internal Use Only

1 2 3 4 7

VOL

PR

OK

6

9

5 8 0

VOL

- 6 -

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. MENU

selects a menu.

4. OK

accepts your selection or displays the current mode.

FF / GG

(Volume Down/Up)

adjusts the volume. adjusts menu settings.

DD / EE

(Programme Up/Down)

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

5. REMOTE CONTROL SENSOR

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

function.)

6. AUDIO/VIDEO IN SOCKETS (AV IN3)

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

1 2 5 3 4

VIDEO L/MONO RAUDIO

AV IN3

6

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@@g @@g @@g @@g @@g @@g @@@@@@@@ @@@@@@@@

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LGE Internal Use Only

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 CW62C Chassis.

V Test and Inspection Method

1) Capability: It follows the TV QC Standard of LGE.

2) Standards of Etc. requirement

- Safety: IEC60065

-EMC : CE standard(EN55020,EN55013)

V Test Condition

Conduct the test as mentioned below.

2.1 Temperature : 25 ± 5°C ( CST 40±5°C)

2.2 Relative Humidity : 65

± 10%

2.3 Power Voltage :

2.4 Follow each drawing or spec for spec and performance of parts, based upon P/N of B.O.M.

2.5 Warm up TV set for more than 20min. before the measurement (If no problem in capability,this allow omitted)

No

1

2

3

4

5

6

7

Item

Receiving System

Receiving Channel

Input Voltage

Market

Picture inch Tuning System

Operating Environment

Storage Environment

Remark Korea,Japan,Taiwan,North America,Middle South American EU /Non EU MODEL

OPTION

Korea,Taiwan,North America. Middle south American

Japan

1)EU/Non EU Model

2)NTSC-M (Multi-model NTSC-M)

Korea Middle south America North America Japan Taiwan NON-EU EU

NTSC MODEL

PAL MODEL 200 PR(W/O TXT )

Specification

1) NTSC M

2) NTSC M/ PAL M/N

1) PAL,SECAM BG

2) PAL/SECAM DK

3) PAL-I/I

4) NTSC M

5) NTSC 4.43(AV)

6) SECAM L/L

7) NTSC M/PAL M/N

1) VHF : 02~13 UHF : 14~69 CATV : 02~125

2) VHF/UHF : 1~62CH

CATV : C13~C38CH TOTAL 88CH

3) VHF : E2 ~ E12

UHF : E21 ~ E69

CATV : S1 ~ S20

HYPER : S21 ~ S41

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

AC 220V, 60Hz AC 100 ~ 240V, 50/60Hz AC 120V, 60Hz AC 100V, 50/60Hz AC 110V, 60Hz AC 110 ~ 240 V/50Hz, 60Hz AC 230 V 50/60 Hz Korea, Japan, Taiwan, North America. Middle South American ,Filipine, China, Middle Asia, Asia, EU, CIS FLAT 29” FS FVS 100 program

1)Temp : 0 ~ 45 deg

2)Humidity : under 85 %

1)Temp : -20 ~ 60 deg

2)Humidity : under 85 %

V General Specification

Market Place

Miesast/Africa

EU/CIS

Band

LG LG

Standard input Voltage

110 ~240 V 50/60Hz

230V 50Hz

Remark

Initial

- 7 -

LGE Internal Use Only

1. Application Object

This specification can be applied to all the television related to CW62C Chassis

2. Notes

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

an isolation transformer. However,operating it using a

transformer between the power supply line and chassis

input to prevent electric shock and to protect the test instrument.

(2)All adjustments must be done in correct sequence.

However, for better productivity, it can be changed in a prepermitted range.

(3) Environment conditions: If not specified, it must be done in

following conditions.

1) Temperature: 25±5°C

2) Humidity : 65±10% (4) AC Voltage 220V ±10% (5) If not specified, the receiver must be operated for more

than 20 minutes prior to the adjustment.

(6) Signal: Received the standard color signal. (65dB±1dBuV)

PAL/SECAM: LG standard signal means the digital pattern PAL_EU 05CH

3. Adjust Item

3.1.1. Preparation for Adjustment.

- Receive PAL-B/G 07ch.(Cross hatch pattern) likes fig.1.

- Select the Picture mode to Standard or clear.

3.1.2. Adjustment.1

Adjust FOCUS VOLUME(the top volume of FBT)

¨and make the FOCUS of vertical line on the quarter of screen(red area in fig.1) achieve the best state.

3.2. Purity and Convergence adjustment

Following direction is a case using of None-ITC CPT for CPT manufacture factory. This adjustment should be done as below direction.

3.2.1. Purity adjustment

a. Do degauss CPT and Cabinet b. Receive Red Raster signal. (Gumi PG50ch.) c. Unfasten fixing Screw of DY, close DY to CPT Funnel DY

as possible as you can.

d. Make R-Land be centered as cross Purity Magnet

That time,4th 6th magnet should keep free gauss status.

e. Make uniform RED Raster as moving DY,

Check there is purity problem or not on R/G/B, white

Raster.Then, Fix screw of DY.

(At this time, be careful about inclination and DY should be

fixed keeping horizontality)

f. Check the TV in direction of EAST, WEST, SOUTH,

NORTH,. Adjust with supporting MAGNET when adjustment is not operated ..

3.2.2. Adjustment for Convergence

This adjustment should be operated at the best condition of

FOCUS after finishing the PURITY adjustment.

1) BACK RASTER receives black CROSS HATCH signal.

2) Adjust Brightness so that there are 9-12 dots.

3) Widen two tabs of 4pole Magnet with equal angles and accord red, blue vertical lines at the center of screen.

4) With keeping angle of "c. clause", rotate tab and accord red/blue, green vertical lines at the center of screen.

- 8 -

ADJUSTMENT INSTRUCTIONS

A

B

<Fig 1. Cross-Hatch Pattern(NTSC:US 09CH, PAL:E-7 CH)

Integrate DY and Magnet into CPT

CPT Assembly

As preparatory operations before assembling CPT, wind cotton Tape for protecting to CPT NECK and DY, CPT connection parts. At this moment, end of tape should be over-lapped and wound in direct route to the NECK.

It needs minimum 15 minutes for heat run under "standard" picture condition.

DY FIXED Torque 9~11 kg f.cm

Fix the Magnet to the position as shown picture below. Be careful not to make CPT neck shadow while adjusting DY.

HEAT RUN

Degaussing

STC Pre-Adjustment

Purity adjustment

DY Fixing

SCREEN Voltage adj.

W/B Fix

FOCUS adjustment

STC adujustment

DYC adujustment

Fig.2 Adjustment Sequence

LGE Internal Use Only

Convergence Magnet

15 ~ 20mm

6Pole

4

2

5) Widen two tabs of 6pole Magnet with equal angles and accord red, blue vertical lines at the center of screen.

6) With keeping angle of "e. clause", repeat the adjustment from c to e keeping in mind the movement of red, blue, green when the horizontal lines are twisted.

7) Move DY up, down, left, right and make the convergence to be optimal condition and stick rubber wedge to CPT so that the DY not to move.

3.3 SCREEN & WHITE BALANCE Adjusting

3.3.1. Manual Adjustment Method (use remoncon for adjusting)

1) Adjust in on RF signal condition or no signal condition.

2) Press ADJ KEY of SVC T/X and select 2.SCREEN ADJ key for adjustment and generate horizontal line.

Turn the Screen Volume so that horizontal line not to be

shown and then change oppositely to finish the adjustment at the showing place.

3.3.2. WHITE BALANCE Manual Adjustment.( INSTART -> SERVICE1)

1) TV set receive 100% White Pattern signal

2) In the state of default setting,adjust BLO-R(R CUT), BLOG(G CUT)

3) In default setting Data

BG(B-DRIVE) is 32,adjust RG(R-

DRIVE), GG(G-DRIVE)

X,Y coordinate satisfy color coordinate below,adjust HIGH

LIGHT(35FL)°

Adjust repeatedly until HIGH LIGHT, LOW LIGHT match.

W/B setting default data refers to W/B TABLE based on

different MODEL.

1. IC

2. White balance IIC Parameter (Address)

3.Color coordinate

3.4 Deflection Setting Data Adjustment

3.4.1. Adjustment Preparation

(1) TV set receive Digital pattern (PAL: E5ch.) (2) Deflection setting data adjustment can be done only with

remote control.

(3) Press the “INSTART” Key on the factory remote control

continuously to enter Deflection Adjustment mode.

(4) Press the CH

D ,E Key to select adjustment item.

(5) Press the

F ,G Key to change the data.

3.4.2. Adjustment

1.Deflection Setting Data Adjustment,adjust in N50Hz (PAL) mode firstly, In USB applied models,PAL Mullti regions,N60Hz(Digtal Pattern)

needs defleetion data adjustment.(07.09.11) then separately adjust N60Hz(NTSC), Z60Hz, N50Hz, W50Hz, Z50Hz.(Model with ARC function)

(In N60Hz adjustment, data more than N60Hz can auto transfer accordingly to N60Hz compensate value, please pay attention to it.)

2. Korea Model adjust only in N60Hz.

3. Middle/south America Model first adjust in N60HZ,then in N50(PAL-N ).

4. After finishing deflection setting data adjustment, press ENTER KEY,then save it and escape adjustment Mode.

Deflection Setting ITEM

1. V SLOPE

CPT center line aim at black background !

2. V SHIFT (VS)

Keep accord with vertical center line of received picture and

CPT

3. V LINEAR (VL)

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

E05 CH.

Program Sub Add

Start Bit Stop Bit

Offset

Polarity

EP_Rom_S

B(R)_Amp

Win31_wb TWB

20

5 0 0 1

36

B(R)_Cut

Win31_wb TWB

17

5 0 0 1

33

G_Amp

Win31_wb TWB

21

5 0 0 0

37

- 9 -

Item

X Y

Color

Temperature

288 295

9000

degree

268 273

1300

degree

267 276

1300

degree

282

288 10000 degree

266

282 13000 degree

EU

N-EU

KOREA /Taiwan

Middle/South

America

Philippines

<Table 1> WHITE BALANCE Color Coordinate

Item

BLO-R(R CUT)

BLO-G(G CUT)

RG(R DRIVE) GG(G DRIVE) BG (B DRIVE)

LOW

LIGHT

HIGH

LIGHT

0 ~ 63 0 ~ 63 0 ~ 63 0 ~ 63 0 ~ 63

32 32 32 32 32

PAL

fixed

Range

default setting data

remarks

<Table 2> WHITE BALANCE default setting data

<Table 3>W/B auto adjust machine setting Table

VCD IC

EP_ROM

Name

Maker

NOTE

Program

Vcd Slave

Win31_wb

TWB

8A

Eeprom_Slave

Win31_wb

TWB

A0

Speed1Delay

30

SPEED/PLUS

2

22

2

G_Cut

Win31_wb TWB

18

5 0 0 0

34

Mode

High Light

Low

Light

0 0 0 0

Algorithm

LGE Internal Use Only

4. V AMPLIT (V AMPITUDE)

PAL signal: Adjust upper and lower part of circle from the effective

screen of the CPT to be distance of 6~7mm .

5. H SHIFT (HS)

Adjust the vertical center line of a digital circle pattern is in accord with geometric vertical center of the CPT.

6. EW WIDTH (EW)

Adjust outer line of the left/right outer lattice to be united with

effective boundary surface of CPT.

Adjust of [Fig 4] 0~25% scope on external lattice from PAL

adjustment.

7. EW PARAB (EW PARABOLA)

Adjust so that middle portion of the outer most left and right vertical line looks like parallel with vertical lines of the CPT.

8. EW TRAPE (EW TRAPEZOID)

Keep accord with the top and the undersurface horizontal scope.

(When picture distorts£¨adjust until it is the square.)

9. EW UPCOR & EW LOCORR

Adjust so that corner vertical line of upper-left ,upper-right, lower-

left and lower-right to be optimization.10. H BOW

Adjust until distortion scope of the edge part in the top and the undersurface of the picture are the same.

11. H PARALL (ANGLE)

In angle adjustment, adjust until inclination of center vertical line

should be vertical precisely.

12. SCORRECT (S CORRECTION)

Adjust so that the lattice scopes of top, center, bottom of received pattern are the same. Use the default setting data (Initial data) of CPT owing to using DY data of CPT.

13. V SCROLL

Keep accord with the geometry vertical center line of received picture and the vertical center of CPT.

14. V ZOOM

VERTICAL ZOOM

15. WBR

16. WBF

17. PIP_ H (PIP H Position) Adjustment* - option

In PAL Channel (E5 CH), when adjust PIP_H position, it will

automatic convert into Double Window Mode.

PIP H Position adjust stand-by picture state, use VOL+, - KEY to

move H-Position or V-Position of sub-picture.

When PIP picture and main picture connect, press VOL+ KEY to

adjust.

3.5 Deflection setting default

- P A L

[Table 4] Deflection setting default based on different model

(SERVICE 2)

- 10 -

[Fig.5] Cross-Hatch Pattern (PAL:E-7 CH)

CRNU

CRNL

CRNU6

EP

CRNL6

Adjusting Point

Actual picture size

[fig.4] PAL Digital Pattern (EU05CH)

[Fig.5] PIP H Position Adjust Picture

LGE Internal Use Only