SHARP LC-20S1E Service Manual

LC-20S1E

SERVICE MANUAL

S83H2LC-20S1E

LCD COLOUR TELEVISION

MODEL

In the interests of user-safety (Required by safety regulations in some countries) the set should be restored to its original condition and only parts identical to those specified should be used.

CONTENTS

» IMPORTANT SERVICE SAFETY PRECAUTION ........................................................................................2

» SPECIFICATIONS ........................................................................................................................................4

» OPERATION MANUAL .................................................................................................................................5

» DIMENSIONS ...............................................................................................................................................7

» REMOVING OF MAJOR PARTS ..................................................................................................................8

» ADJUSTING PROCEDURE OF EACH SECTION .....................................................................................12

» TROUBLE SHOOTING TABLE...................................................................................................................16

» CHASSIS LAYOUT .....................................................................................................................................22

» BLOCK DIAGRAM......................................................................................................................................24

» OVERALL WIRING DIAGRAM ...................................................................................................................26

» DESCRIPTION OF SCHEMATIC DIAGRAM .............................................................................................28

» SCHEMATIC DIAGRAM .............................................................................................................................29

» PRINTED WIRING BOARD ASSEMBLIES................................................................................................53

» REPLACEMENT PARTS LIST....................................................................................................................64

» PACKING OF THE SET ..............................................................................................................................77

LC-20S1E

Page

SHARP CORPORATION

LC-20S1E

IMPORTANT SERVICE SAFETY PRECAUTION

Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and the servicing guidelines which follow:

WARNING

1. For continued safety, no modification of any circuit should be attempted.

2. Disconnect AC power before servicing.

CAUTION: FOR CONTINUED PROTECTION AGAINST A RISK OF FIRE REPLACE ONLY WITH SAME TYPE F3301(2A, 250V), F3302(1.25A, 250V), F6700 (1.25A, 250V), F6701 (1.25A, 250V), F6702 (1.25A, 250V), F6703 (1.25A, 250V) AND F6704 (1.25A, 250V) FUSE.

BEFORE RETURNING THE RECEIVER (Fire & Shock Hazard)

Before returning the receiver to the user, perform the following safety checks:

1. Inspect all lead dress to make certain that leads are not pinched, and check that hardware is not lodged between the chassis and other metal parts in the receiver.

2. Inspect all protective devices such as non-metallic control knobs, insulation materials, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacitor networks, mechanical insulators, etc.

3. To be sure that no shock hazard exists, check for leakage current in the following manner.

• Plug the AC cord directly into a 110~240 volt A C outlet, and connect the DC power cable into the receiver's DC jack. (Do not use an isolation transformer for this test).

• Using two clip leads, connect a 50k ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with all exposed metal cabinet parts and a known earth ground, such as electrical conduit or electrical ground connected to an earth ground.

• Use an AC voltmeter ha ving with 5000 ohm per volt, or higher, sensitivity or measure the AC voltage drop across the resistor.

• Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor. All checks must be repeated with the AC cord plug connection reversed. (If necessar y, a nonpolarized adaptor plug must be used only for the purpose of completing these checks.) Any reading of 0.75V peak (this corresponds to 0.5 mA. peak AC.) or more is excessive and indicates a potential shock hazard which must be corrected before returning the monitor to the owner.

DVM

AC SCALE

50k ohm

10W

0.15 F

TEST PROBE

TO EXPOSED METAL PARTS

CONNECT TO KNOWN EARTH GROUND

23456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012

SAFETY NOTICE

Many electrical and mechanical parts in LCD television have special safety-related characteristics. These characteristics are often not evident from visual inspection, nor can protection afforded by them be necessarily increased by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual; electrical

and shaded areas in the

Schematic Diagrams.

For continued protection, replacement parts must be identical to those used in the original circuit. The use of a substitute replacement parts which do not have the same safety characteristics as the factory recommended replacement parts shown in this service manual, may create shock, fire or other hazards.

components having such features are identified b y " å"

23456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012

Replacement Parts Lists and

LC-20S1E

Precautions for using lead-free solder

1 Employing lead-free solder

"MAIN PWB" of this model employs lead-free solder . The LF symbol indicates lead-free solder, and is attached on the PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder. Example:

L Fa

Indicates lead-free solder of tin, silver and copper.

2 Using lead-free wire solder

When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional lead wire solder may cause damage or accident due to cracks. As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40°C, we recommend you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldering bit, contact our service station or ser vice branch in your area.

3 Soldering

As the melting point of lead-free solder (Sn-Ag-Cu) is about 220°C which is higher than the conventional lead solder by 40°C, and as it has poor solder wettability, you may be apt to keep the soldering bit in contact with the PWB for extended period of time. However, Since the land may be peeled off or the maximum heat-resistance temperature of parts may be exceeded, remov e the bit from the PWB as soon as you confirm the steady soldering condition. Lead-free solder contains more tin, and the end of the soldering bit may be easily corroded. Make sure to turn on and off the power of the bit as required. If a different type of solder stays on the tip of the soldering bit, it is allo y ed with lead-free solder. Clean the bit after every use of it. When the tip of the soldering bit is blackened during use, file it with steel wool or fine sandpaper.

Be careful when replacing parts with polarity indication on the PWB silk.

Lead-free wire solder for servicing

Part No. ★ Description Code ZHNDAi123250E J φ0.3mm 250g(1roll) BL ZHNDAi126500E J φ0.6mm 500g(1roll) BK ZHNDAi12801KE J φ1.0mm 1kg(1roll) BM

LC-20S1E

SPECIFICATIONS

Item 20" LCD COLOUR TV, Model: LC-20S1E LCD panel 20" Advanced Super View & BLACK TFT LCD Number of dots 921,600 dots Video colour system PAL/SECAM/NTSC TV TV-Standard (CCIR) B/G, I, D/K, L

TV-Tuning System Auto preset 200 ch. STEREO/BILINGUAL NICAM, A2 stereo AUTO PRESET YES

CATV ~Hyper Band Brightness 430 cd/m Lamp life 60,000 hours Viewing angles H: 170¡ V: 170¡ Audio amplifier 2.1 W × 2 Speakers 4 cm × 7 cm 2 pcs. Terminals AV-IN 1 21 pin Euro-SCART

AV-IN 2 S-VIDEO, VIDEO, AUDIO

OUT AUDIO

Antenna DIN

Headphones 3.5 mm ¿ jack (Front) OSD language English/German/French/Spanish/Italian/Swedish/Dutch/Russian Power requirement DC 12 V, AC 110 V — 240 V, 50/60 Hz Weight 6.4 kg w/o accessories Accessories Operation Manual, Remote Control, Batteries (× 2), AC adapter, AC cord,

Cable clamp

■ As a part of policy of continuous improvement, SHARP reserves the right to make design and specification changes for product improvement without prior notice. The performance specification figures indicated are nominal values of production units. There may be some deviations from these values in individual units.

OPERATION MANUAL

35°

Part Names of Main Unit

Controls

Note:

• TV/VIDEO, CH (

)/(

)

(–)/(+) (Volume) and MENU on the main unit have the same functions as the same buttons on the remote

control. Fundamentally, this operation manual provides a description based on operation using the remote control.

Headphone jack

Plug the headphone mini-plug into the Headphone jack located on

the front of the TV set.

OPC sensor

Remote sensor

OPC sensor indicator (Optical Picture Control)

The Optical Picture Control indicator lights up green when the

Brightness is set to Auto.

POWER/STANDBY/Remote sensor indicator

A green indicator lights when the power is on and a red indicator

lights when in the standby mode (the indicator will not light when the

main power is off). A red indicator blinks when the TV set receives

the remote control signal.

(–)/(+) (Volume)

Upper control panel

CH (

)/( )

TV/VIDEO

(MAIN POWER)

The screen can be adjusted

backwards to an angle between

12 degrees and 35 degrees.

The screen cannot be set up

straight. When changing the

angle, make sure to hold the

stand and adjust the screen to

the best viewable angle.

Speaker

Adjustable range

Terminals

POWER INPUT DC 12V

Antenna

AV-IN 1

(21-pin Euro-SCART)

AUDIO OUT (R)

AUDIO OUT (L)

Rear View

Carrying handle

AUDIO (R)

AUDIO (L)

VIDEO

S-VIDEO

AV-IN2

●The screen can be adjusted back-

wards to an angle between 12 and 35

degrees.

When changing the angle, make sure

to hold the stand and adjust to the

best viewable angle.

* Be careful to prevent the product from

falling over when adjusting the angle.

Also place the product on a stable

base.

Stand

Round lock for Kensington

Security Standard Slot.

LC-20S1E

Part Names of Remote Control

REVEAL

HOLD

END

MENUSOUND

SUBTITLE

SUBPAGE

TEXT

ROTATE

TV/VIDEO

REVEAL

HOLD

END

MENUSOUND

SUBTITLE

SUBPAGE

TEXT

ROTATE

BRIGHT

Selects the brightness

and OPC of the display.

HOLD

Temporarily holds the

current Teletext page.

(Power)

OK, Programme Table

SUBTITLE

Displays the Teletext

Subtitle directly.

SOUND

Switches the sound

mode.

Right / Left Selection

Red, Picture Menu

Green, Sound Menu

(+)/(-) (Volume)

Channel Select

(Flashback)

Returns to the previous

channel.

SUBPAGE

Displays the Teletext

Subpage directly.

TEXT

Displays the Teletext mode

screen.

REVEAL

Displays hidden information

such as solutions to riddles

and puzzles.

ROTATE

Rotates the display in every

direction.

END

Returns to normal screen.

Upwards/Downwards

Selection, zoom display

function (Teletext mode)

Displays the TV menu.

Cyan, Status Display

Turns on the status display

when the menu is not

displayed.

Yellow,

Timer function Menu

(Mute)

Switches the sound on and off.

CH (

)/(

)

Displays previous/next page.

(Teletext mode)

TV/VIDEO

Switches the input source

between AV1, AV2 and

TV mode.

Installing Batteries in the Remote Control

Before using the LCD TV set for the first time, install the two R-03 (“AAA” size, UM/SUM-4) batteries supplied in the remote

control. When the batteries become depleted and the remote control fails to operate, replace the batteries with new R-03

(“AAA” size, UM/SUM-4) batteries.

Open the battery cover.

Insert two R-03 (“AAA” size,

UM/SUM-4) batteries.

Replace the battery cover.

■ Position the positive and

negative ends of the

batteries as indicated in

the compartment.

Caution!

Precautions regarding batteries

■ Improper use of batteries can result in a leakage of chemicals and/or explosion. Be sure to follow the instructions below.

• Place batteries with their terminals corresponding to the (+) and (–) indications.

• Different types of batteries have different characteristics. Do not mix batteries of different types.

• Do not mix old and new batteries. Mixing old and new batteries can shorten the life of new batteries and/or cause old

batteries to leak chemicals.

• Remove batteries as soon as they are depleted. Chemicals that leak from batteries can cause a rash. If chemical

leakage is found, wipe it off with a cloth.

• The batteries supplied with the product may have a shorter life expectancy due to storage conditions.

• If the remote control is not to be used for an extended period of time, remove the batteries from the remote control.

■ Engaging the lower

claw with the remote

control, close the

cover.

■ Slide the cover while

pressing the ( ) part.

–

404

LC-20S1E

DIMENSIONS

Unit: mm

172

12°

336

156

356

244

283

107

263

474

403.3

300.8

411

228.5

160

134

198

100

LC-20S1E

REMOVING OF MAJOR PARTS

1. Remove the stand fixing screws (4 pcs.).

2. Remove the terminal cover.

3. Remove the terminal section fixing screws (3 pcs.).

4. Remove the cabinet B fixing screws (9 pcs.).

5. Remove the cabinet B after opening from the direction of an arrow.

6. Remove the reinforcement angle fixing screws (2 pcs.).

7. Detach the connector from each PWB.

Terminal Cover

Cabinet A

P6706

P6700

P6706

P6700

P6701

P6702

P6703

P6704

Tuner PWB

SC3901

P3305

SC2001

P701

Reinforcement Angle

P3601

P1900

SC1204

SC1202

SC1203

P2001

Main PWB

Stand

Cabinet B

Inverter PWB

P4003

P4001

7 7

R/C,LED PWB

LC-20S1E

8. Remove the 3 lock screws from the main PWB and undo the hooks a and b. Lifting the other PWBs close to the hooks, draw out the main PWB.

9. Remove the 4 lock screws from the tuner PWB and undo the hooks c and d. Detach the chassis frame (right), together with its terminals, from the tuner PWB. Undo the hooks e and f in the same way. Detach the chassis frame (left), together with its terminals, from the tuner PWB.

10. Remove the 3 lock screws from the inverter PWB and take out the inverter PWB.

11. Remove the 2 lock screws from the R/C, LED PWB and take out the R/C, LED PWB.

12. Remove the 4 lock screws each from the right and left speakers and take out both the speakers.

Chassis Frame (R)

Inverter PWB

Tuner PWB

LCD panel unit

Main PWB

Chassis Frame (L)

R/C,LED PWB

Speaker (L)Speaker (R)

1212 11

LC-20S1E

» Precautions in handling the LCD panels

1. Work in a clean room (with humidities below 50%).

2. Be sure to wear an anti-static armband.

3. Handle the panels on an electro-conductive mat.

4. Be careful not to fall, shake and shock the panels.

13. Remove the 3 lock screws from the LCD panel and detach the LCD panel.

14. Remove the reflection/polarization sheet, prism sheet, diffusion sheet and diffusion panel.

15. Detach the lamp holders (top)-A, (top)-B and (bottom) from the lamp unit assembly.

16. Detach the reflection sheets (top) and (bottom) from the back shield.

Back shield Ass'y

(CSLDMA251WJ01)

Reflection Sheet (Top)

(PSHEPA103WJZZ)

Lamp Holder (Bottom)

(LHLDZA213WJKZ)

Lamp Unit Ass'y

(CLMP-A024WJ01)

Reflection/Deflection Sheet

(PSHEPA101WJZZ)

Diffusion Sheet

(PSHEPA127WJZZ)

20" LCD Panel Unit

Lamp Holder (Top)-A

(LHLDZA211WJKZ)

(PCOVUA014WJZZ)

Prism Sheet

(PSHEPA102WJZZ)

Reflection Sheet (Bottom)

(PSHEPA104WJZZ)

Lamp Clip

(LHLDZA214WJKZ)

Lamp Holder (Top)-B

(LHLDZA212WJKZ)

Diffusion Plate

LC-20S1E

» Precautions at the time of the side B(back) service of main and Inverter unit.

1. Remove only SC2001 of the FFC for connection between Main unit(SC2001) and Tuner unit(SC3901), and connect the extended cable (QCNW-A369WJZZ) for service.

2. Remove only P701 of the FFC for connection between Main unit(P701) and Tuner unit(P1900), and connect the extended cable (QCNW-B594WJZZ) for service.

3. Remove the main unit fixing screws(3 pcs.), a substrate is reversed.

4. Remove the Inverter unit fixing screws (3 pcs.), a substrate is reversed.

Tuner PWB

P6706

P3601

P1900

Inverter

PWB

(Side B)

SC3901

SC2001

P701

P2001

SC1202

SC1204

SC1203

Main PWB

Inverter PWB

Main PWB

(Side B)

Step Part No. Description

1 QCNW-A369WJZZ Extension Cable 50-pin Main (SC2001)-Tuner (SC3901) 2 QCNW-B594WJZZ Extension Cable 13-pin Main (P701)-Tuner (P1900)

LC-20S1E

ADJUSTING PROCEDURE OF EACH SECTION

The best adjustment is made before shipping. If any position deviation is found or after part replace is performed, adjust as follows.

Preparation for adjustments

Use the dedicated AC adaptor or stable DC power supply. LC-20S1E AC adaptor: UADP-A043WJPZ DC power supply: 12V 5.0A

1.Adjusting procedure

• Checker adjustment Power ON (Adjustment processing mode) → +B adjustment → Counter bias adjustment → TAMP (Contrast) adjustment → White balance adjustment

2.Entering the adjustment processing mode

There are the following two methods.

• Setting the pin (81)(KEY4) or pin (82)(KEY5) of IC2001 (microprocessor) to GND, turn on the power.

• A "POWER" key is made on with pushing an "TV/VIDEO" and "MENU" keys at the same time.(K of the inspection

process mode is displayed b y the upper left of the image plane.) → Next, "CH (Ù)" and "V OL (–)" ke ys are pushed

at the same time.(It becomes the image plane of the adjustment process mode.).....When it is canceled, it is made

to turn it off.(Even off in the "MAIN POWER" key, off with R/C are good.)

3.Key operation in the adjustment process mode

• The receiving channel UP/DOWN is performed with the "CH (ù)/(Ù)" keys. One push ... The UP/DOWN tuning is performed per channel. Continuous push ... The UP/DOWN search is performed until a next receivable station is found.

• V arious adjustments The adjustment is performed for each item by the "MENU", "Menu cursor", "CH (ù)/(Ù)" or "VOL (+)/(–)" keys (LCD TV set and remote control).

• Adjustment item is chosen with the Menu cursor upward/downward keys.

• The adjustment item makes a toggle operation with the “MENU” key input. (Next item)

If the "MENU" key is input while the bottom item is selected, it moves to the top item on the next page.

• Press the auto preset button on the remote controller in the adjustment process mode, and the top item of the next page will show up regardless of which item appears now. Page 1 → Page 2 → ... → Page 66 → Page 1

• Press the manual memory button on the remote controller in the adjustment process mode, and the top item of the same page will show up.

• UP/DOWN of each adjustment vale selected is performed with the VOL (+)/(–) keys input.

LC-20S1E

4.Initialization

When the microprocessor (IC2001) or the EEPROM (IC2007, IC2009) has been replaced or when the EEPROM has been initialized, readjust the each adjustments. 4-1. Connect the pins (81) and (82) of IC2001 (microprocessor) to GND, and turn on the power. 4-2. Check that the model name is (A661). 4-3. Select the inch size (20). 4-4. LED changes green from red after setting finish and about 15 seconds, initialization is completed, and it

becomes adjustment mode.

4-5. Writing the model-by-model data

For the Ver.1.00A microprocessor, get it initialized first and then make the settings, listed below, on it. (The microprocessor version is indicated at the bottom of Adjustment Process Page 1.)

Ver.1.00A data reprogramming (INCH SIZE [20])

Adjustment process page

11 12 47 47

PAL BRIGHTNESS PAL TV PKCFSOFT7C PAL TV LDLY PAL AV LDLY

Item

OSD settings

-1 → -8 6 → 4

0 → +1 0 → +1

Ver.1.00A data reprogramming (INCH SIZE [20]) (Only for U.K)

Adjustment process page

11 11 11 11 12

Item PAL TV COLOR PAL AV COLOR PAL TV TINT PAL TV TINT PAL TV PKCFSOFT7C

OSD settings

41 → 34 41 → 34

0 → +5 0 → +5

4 → 6

LC-20S1E

5.Adjustment

5-1. +B adjustment...Page 1 +B-ADJ

Adjust the voltage of the pin (4) of P1900 to 5.00 ±0.02V with R3714. Note: Since 5.0V is a reference voltage of all power voltage, adjust it precisely.

5-2. Counter-bias adjustment

Vary the "COM BIAS" setting on Page 2 of the adjustment process mode so that the contrast be sharpest (black looks most sinking).

5-3. TAMP adjustment

1) Receive the upper left of 75% white half colour bar signal.

2) See if the "Y" reading on page 2 of the adjustment process mode is somewhere following. If not, make the "PAL TAMP" adjustment to get the "Y" reading in the range of AE thru BD.

3) If the adjustment of "PAL TAMP" is executed, write its adjustment value to the "SECAM TAMP" manually.

(Screen of the page 2 of the adjustment processing menu OSD)

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

0 1 2 3 4 5 6

7 8

10 11

12 13

COM B I AS 9 0

PAL TAMP 27

SECAM TAMP 27 RCUTOF F GCU TOF F

BCU TOF F RGA I GG

BGA I

TAMP

N 0 N

0 0 0

0 0

Y Data

(White 75%)

5-4. White balance adjustment

Adjust "RCUTOFF", "BCUTOFF", "RGAIN" and "BGAIN" on the page 2 of the adjustment processing so as to obtain the colour of the same level as the standard set.

LC-20S1E

M O D E L A661

V E R R O M 1 . 0 0 A

Reset 0

Afterwards, perform the operation check to confirm that the lamp error detection does not function.

Page 1 of the adjustment process

INCH SIZE 20 ERROR NO RESET 5 PUBLIC MODE OFF EXT CONTROL OFF EXT MODE UART UPDATE MODE NORMAL TEXT RESET OFF

6. Factory Setting

6-1. Perform a factory setting after completing all adjustments. 6-2. A "POWER" keys is made on with pushing an "TV/VIDEO" and "MENU" keys at the same time. 6-3. "K" of the inspection process mode is displayed on the screen upper left. 6-4. CH (ù) and VOL (+) keys are pushed about 2 seconds at the same time. 6-5. Release ke ys, if "E" is displayed on the screen upper left and "COMPLETE" is displayed on the bottom of it. 6-6. After a while, a power will be in a standby mode and a setup will be finished. Note: "First installation" serves on "Deutsch".

7. Lamp error detection

7-1. Functional description

This LCD colour television has a function (lamp error detection) to be turned OFF automatically for safety when the lamp or lamp circuit is abnormal. If the lamp or lamp circuit is abnormal, or some other errors happen, and the lamp error detection is executed, the followings occur. 1 The main unit of television is turned OFF 5 seconds after it is turned ON. (The power LED on the front

side of TV turns from green to red.)

2 If the situation 1 happens 5 times sequentially, television can not be turned ON. (The power LED remains

red.)

7-2. Countermeasures 7-2-1.Check when turning OFF the lamp error detection

When television is turned OFF by the lamp error detection mentioned above, it enters the adjustment process with the power LED red. Entering the adjustment process turns OFF the error detection and turns ON TV. This enables the operation check to detect errors in the lamp or lamp circuit. Check whether "ERROR NO RESET" on line 3, page 1 of the adjustment process is 1 or more. If it is 1 or more, it indicates the lamp error detection was executed.

7-2-2.Resetting of the lamp error count

After confirming that the lamp or lamp circuit is normal, reset the lamp error count. Select "ERROR NO RESET" on line 3, page 1 of the adjustment process and set the number to 0 using the volume button.

LC-20S1E

No picture and No sound

Check all the settings microprocessor

’s adjust process menu.

Do F3301 and F3302

function?

Are T3701’s secondary

outputs, +34V, +9V, +5V

and -110V normal?

Replace F3301 and F3302.

Check S4001 and

connection cable.

Is T3701’s primary oscillator

waveform normal?

Check T3701’s secondary

load.

Yes Yes

No No

Yes

Check J3300 periphery and

connection cable.

Replace F6700~F6704.

Yes

Check the OFL line, Q3600,

Q3601 and their peripheral

parts.

Check T6700~T6704,

Q6700~Q6705 and

connection cable.

Back light lamp failure to light up

Is the primary side of

T6700 ~T6704 periphery

short-circuiting?

Replace the back light lamp

with new one and check

again.

Remove F3301 and F3302

and check the load side.

Is there short-circuiting?

Is there short-circuiting of

T3701 primary side periphery,

Q3701, Q3703 and S4001.

Are the pins (120) and (121)

of IC1201 in the "H" state?

Are the outputs of Q3600 and

Q3601 in the

state?

Check the OFL1 line, OFL2

line, IC1201 and their

peripheral parts.

TROUBLE SHOOTING TABLE

TROUBLE SHOOTING TABLE (Continued)

No picture (1/3)

Check all the settings microprocessor

’s adjust process menu.

Is in/output of

IC801 normal?

Is in/output of

IC1201 normal?

Check IC801

and its

peripheral parts.

Check IC1201

and its

peripheral parts.

Check LCD

panel voltages

and waveform.

Yes

No picture

at all

Is voltages at

pins (6), (7) and

(18) of tuner

normal?

Is output at pin

(13) of tuner

normal?

Check the

power line.

Check tuner

and its

peripheral parts.

Is input at pin

(16) of IC802

normal?

Is the pin (3)

of IC802 at "H"

state?

Yes

No TV output

Is the pin (48)

of IC2001 at

"H" state?

Yes

Check the its

line.

Check the its

line.

Check IC802

and its

peripheral parts.

Is input at pin

(7) of IC802

normal?

Check V1_V

line and its

peripheral parts.

No VIDEO 2

output

LC-20S1E

No picture (2/3)

Check all the settings microprocessor

’s adjust process menu.

Is input at pin

(14) of IC802

normal?

Check the V2_V

line and its

peripheral parts.

No VIDEO 1

output

Check the SY-line,

SC-line and their

peripheral parts.

Is input at pin (9)

of IC802 and pin

(1) of IC805

normal?

No S-VIDEO

output

Check IC1201

and its

peripheral parts.

Yes

No TELETEXT

output

Is input at pins (136),

(137), (138), and

(142) of IC1201

normal?

Check the R, G

and B line.

Is output at pins

(57)~(59) of IC1601

normal?

Yes

Check Vout line and

its peripheral parts.

Is input at pin (21) of

IC1601 normal?

Check IC1601 and its

peripheral parts.

TROUBLE SHOOTING TABLE (Continued)

No picture (3/3)

Check all the settings microprocessor

’s adjust process menu.

Is output of

R0~R7

normal?

Is output of

G0~G7

normal?

Is output of

B0~B7

normal?

Yes

Colour is

unusual

Is in/output of

SPIO and

SPOI normal?

No picture

image

inversion

Gradation

defect

Is output of U/D

normal?

Yes

Check R1224, R1227

and their peripheral

parts.

Check R1234 and

its peripheral parts.

Check IC1202, Q1206

and their peripheral

parts.

Check R1231, R1267

and their peripheral

parts.

Check R1268, R1269

and their peripheral

parts.

Is output V0, V7, V21,

V64, V112, V176,

V235 and V255

normal?

Check IC1101 and its

peripheral parts.

LC-20S1E

No sound (1/2)

Check all the settings microprocessor

’s adjust process menu.

Is the pin (53) of

IC2001 in the

"L" state?

Is output at pins

(27) and (28) of

IC1900 normal?

Yes

No sound

from front

speakers

Yes

Muting effect is

on. Check the

FSMUTE line.

Check IC1900

and its

peripheral parts.

Is the pin (52) of

IC2001 in the

"L" state?

Is output at pins

(24) and (25) of

IC1900 normal?

Is output at pins

(1) and (7) of

IC350 normal?

Yes

Muting effect is

on. Check the

HP_MUTE line.

Check IC1900

and its

peripheral parts.

Check IC350

and its

peripheral parts.

No sound

from

headphone

TV sound

failure

Is output at pins

(33) and (34) of

IC1900 normal?

Is output at pins

(1) and (7) of

IC3500 normal?

Check IC1900

and its

peripheral parts.

Check IC3500

and its

peripheral parts.

Yes

No sound

from output

line

Check the tuner

and its

peripheral parts.

Yes

Is output at pin

(11) of Tuner

normal?

Is input at pin

(67) of IC1900.

Check IC1900

and its

peripheral

parts.

Check

Headphone Jack

and connection

cable.

Is output at pins

(8) and (12) of

IC3301 normal?

Check IC3301

and its

peripheral parts.

Check front

speaker and

connection

cable.

Yes

Is output at pins (1)

and (7) of IC1902,

IC1903 and IC1904

normal?

Check IC1902,

IC1903, IC1904 and

their peripheral parts.

TROUBLE SHOOTING TABLE (Continued)

No sound (2/2)

Check all the settings microprocessor

’s adjust process menu.

Yes

No sound from SCART

SCART sound failure

Yes

Check IC1900 and its

peripheral parts.

Is output at pins (36) and (37) of

IC1900 normal?

Check IC1901 and its

peripheral parts.

Is output at pins (1) and (7) of

IC1901 normal?

Check their lines and their

peripheral parts.

Is input at pins (53) and (54) of

IC1900 normal?

Check IC1900 and its

peripheral parts.

Is output at pins (27) and (28) of

IC1900 normal?

LC-20S1E

CHASSIS LAYOUT

INVERTER Unit

TUNER Unit

R/C, LED Unit

87109654321

LC-20S1E

MAIN Unit

1716 1918151413121110

LC-20S1E

BLOCK DIAGRAM

ANTENNA

SC3902

J5000

J5001

SCART

(AV1)

AUDIO IN

AUDIO OUT VIDEO OUT

SDA/RXD

SCL/TXD

SC_R/G/B

S (AV2)INPUT

VIDEO (AV2)INPUT

AUDIO (AV2)INPUT

I C/UART

V1_V

V1.L/R

TV_V

TUNER

I C

SC_L/RO

TV/AV

SELECTOR

IC802

CHROMA

SELECTOR

SIF1

AI_L/R

IC805

AUDIO AMP

IC1901

AMP

IC803(1/2)

ANA_IN1+

SC2_IN_L/R

SC1_OUT_L/R

SC1_IN_L/R

CVBS/SY_IN

AMP

IC803(1/2)

R/G/B_IN

SC_IN

MSP

IC1900

VPC

IC801

VOUT

SYNC SEP

IC804

I C

UART

E PROM

CSYNC

DACM_L/R

DACA_L/R

IC2009

I C

SC2_OUT_L/

I C

MICON IC2001

J3300

DC12V

INPUT

VCC

SIGVCC

INV+B

REG IC2003

REF IC706

DC/DC

CONVERTER

T3701

PWM IC3701

+5V

+3.4V

REG IC2004

+3.4V

Q3709

REG IC708

REG IC806

REG IC707

Q3707

IC3702

Q3708

+3.3V

+9V +8V

+5V +1.8V

+3.3V

+32V –11V

Q3705

+23V +17V

VOLT AGE

CONVERTER

IC705

REG IC704

REG IC701

KEY

Q3703

B12V1A

REG IC702

REG IC709

87109654321

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