Sharp LC-20B5M Schematic

1st Edition

SERVICE MANUAL

LCD COLOUR TELEVISION

LC-20B5M

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 .....................................................................................13

» TROUBLE SHOOTING TABLE...................................................................................................................24

» CHASSIS LAYOUT .....................................................................................................................................28

» BLOCK DIAGRAM......................................................................................................................................30

» OVERALL WIRING DIAGRAM ...................................................................................................................32

» DESCRIPTION OF SCHEMATIC DIAGRAM .............................................................................................34

» SCHEMATIC DIAGRAM .............................................................................................................................35

» PRINTED WIRING BOARD ASSEMBLIES................................................................................................75

» REPLACEMENT PARTS LIST....................................................................................................................86

» PACKING OF THE SET ............................................................................................................................101

LC-20B5M

Page

SHARP CORPORATION

LC-20B5M

2

2

IMPORTANT SERVICE SAFETY PRECAUTION

Ë

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 F3701 (2A, 250V), F3702 (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 µF

TEST PROBE

TO EXPOSED
METAL PARTS

CONNECT TO
KNOWN EARTH
GROUND

234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121

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 by “ å”

234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121

Replacement Parts Lists and

2

LC-20B5M

Precautions for using lead-free solder

1 Employing lead-free solder

"All PWBs" 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 service 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. Mak e 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

3

LC-20B5M

SPECIFICATIONS

ITEMS

LCD panel
Number of pixels 921,600 dots
Video colour systems World multi system

TV Standard (CCIR) I/DK/M/BG
TV Tuning System Auto preset tuning

TV function STEREO/BILINGUAL NICAM-BG, I, DK/A2 stereo-BG

AUTO PRESET Yes

CATV S1~S41 ch. Hyper Band
4-LINE DIGITAL COMB FILTER Yes
Brightness 450 cd/m
Lamp life 60,000 hours*
Viewing angles H: 170° V: 170°
Audio output 2.1 W 2×
Speakers 5.7 cm ø, 2 pcs.

AV1 Composite Video, S-Video, Audio

AV2 IN/OUT Composite Video, Audio IN/Composite Video, Audio OUT
Terminals

Image File Format JPEG files complying with DCF format
OSD LANGUAGE English/Chinese/Arabic
Power requirement DC 12 V, AC 110–240 V, 50/60 Hz
Power Consumption For Asia

Weight 9.2 kg w/o accessories
Accessories Remote control, Batteries ( 2), Antenna cable, AC adapter,

* The typical period of time after which the lamp’s power output will have decreased by about half, given that the AQUOS is used continuously

in a 25°C room under standard lighting and brightness conditions.

■As a part of policy of continuous improvement, SHARP reserves the right to make design and specification changes for the LCD TV set
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.

COMPONENT Y, PB, PR/Audio
Headphone jack 3.5 mm ø jack (Front)
PC Card Slot PC Card Type II (PC Card Adapter)

MODEL

LC-20B5M

19.7" (50 cm) Advanced Super View & BLACK TFT LCD

2

63 W (1.2 W Standby):
AC 230 V (With AC adapter)

For Australia

65 W (1.2 W Standby):
AC 230 V (With AC adapter)

55W : DC 12 V

AC cord,

Cable holder, Operation manual

×

4

OPERATION MANUAL

MAIN POWERMENUVOL

( )

/

( )

TV/VIDEOCH

( )

/

( )

LC-20B5M

Upper control panel

Part Names of Main Unit

Controls

NOTE

• TV/VIDEO, CH (

)/(

), VOL (–)/(+) 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 LCD TV set.

OPC sensor

Remote sensor

OPC indicator (Optical Picture Control)

The

Optical Picture Control indicator lights up green when the

“Backlight” is set to “Auto (OPC)”.

POWER indicator

POWER indicator lights up green when the power is on, and

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

when the main power is off). The indicator lights up orange

when the wake-up timer is set.

* The examples used throughout this manual are based on

the LC-20B5M model.

To change the vertical angle of the LCD TV

set, tilt

the screen up to 5 degrees forward or

10 degrees backward. The LCD TV set can

also be rotated up to 25 degrees to right and

left. Please

adjust the angle so that the LCD

TV set can be watched most comfortably.

Card Lamp

When timer recording is set: Orange

When recording: Red

Standby: Green

PC Card Slot

Speaker

Tilt the display by grabbing onto

the carrying handle while securely

holding down the stand with your

other hand.

How to adjust the angle

Speaker

Terminals

S-VIDEO

AV-IN1

VIDEO

AUDIO (R)

AUDIO (L)

VIDEO

AUDIO (R)

AUDIO (L)

AV-IN2/OUT

Y

ANT. (Antenna terminal)

POWER INPUT (DC12V)

AUDIO (L)

AUDIO (R)

P

B

P

R

COMPONENT

Carrying handle

Rear View

How to fix the cables

• Pull the cables connected to each terminal through the holes and close the left and right terminal covers.

Push the cables into the grooves of the support covers. Insert the cable holder (supplied) from above the

support cover and fix the cables.

Terminal cover

Cable holder

Terminal cover

Support cover

LC-20B5M

5

LC-20B5M

Part Names of Remote Control

Move the cursor to the upwards

(Select the menu items)

/

Still

(Pause the motion picture playback or card recording)

Move the cursor to the right

(Select the menu items)

/

Fast Forward

(Fast forwards the picture)

Move the cursor to the downwards

(Select the menu items)

/

Stop

(stop the motion picture playback or card recording)

OK

(Set the menu or items by selecting the cursor)

/

Play

(Playback the card)

Move the cursor to the left

(Select the menu items)

/

Fast Reverse

(Fast reverses the picture)

How to use the cursor during the

motion picture playback

SUBTITLE

Displays the Teletext

Subtitle directly.

HOLD

Temporarily holds the

current Teletext page.

REC

Records the motion

picture.

(Mute)

Switches the sound on and off.

Yellow,

Timer function Menu

Cyan, Status Display

Channel Select

MENU

Displays the TV menu or return

to normal screen.

VOL (+)/(

-

)

(Flashback)

Returns to the previous

channel.

Red, Picture Menu

END

Returns to normal screen

in Teletext mode.

RETURN

Return to the previous screen.

TEXT

Displays the Teletext mode

screen.

POWER

MPX

Switches the audio

mode.

REVEAL

Displays hidden information

such as solutions to riddles

and puzzles.

CARD

Switches the motion and

still picture.

SUBPAGE

Displays the Teletext

Subpage directly.

CAPTURE

Records the still picture.

TV/VIDEO

Switches the input source

between AV1, AV2, COMPONENT,

CARD and TV mode.

BACKLIGHT

Selects the brightness and

OPC of the display.

Green, Sound Menu

CH ( )/( )

Installing Batteries in the Remote Control

Before using the LCD TV set for the first time, install the two “AAA” size batteries supplied in the remote control. When the

batteries become depleted and the remote control fails to operate, replace the batteries with new “AAA” size batteries.

1

Open the battery cover.

2

Insert two “AAA” size batteries.

3

Close the battery cover.

■ Place batteries with their

terminals corresponding to

the (+) and (–) indications in

the battery 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 LCD TV set may have a shorter operating time 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.

Preparation

■ Engaging the lower

claw with the remote

control, close the

cover.

■ Slide the cover while

pressing the (

) part.

+

–

+

–

6

DIMENSIONS

LC-20B5M

452 (including rubber foot)

212

384

673

403.3

39359

300.8

261

Unit: mm

6880

450 (including rubber foot)

100

178

244

100

47

7

LC-20B5M

REMOVING OF MAJOR PARTS

1. Remove the four lock screws from the stand, and detach the stand.

2. Remove the terminal covers (large and small).

3. Remove the three terminal screws.

4. Remove the fourteen lock screws from the cabinet B.

5. With the card eject button held down, open the cabinet in order of
sliding it toward the PC card slot.

6. Remove the four lock screws from the stand angle, and detach the reinforcement angle.

7. Remove the wire holder and tape, and disconnect the connecting cable.

8. Disconnect all the connectors from all the PWBs.

5-4

5-3

PC Card slot

Terminal Cover (S)

4

2

Cabinet B

5-2

5-1

Cabinet A

5-1

thru

, and detach the cabinet B by

5-6

6

5-6

5

1

5-5

Reinforcement Angle

3

2

Stand

Terminal Cover (L)

Tape

7

Card LED PWB

P5003

P2005

P9001

8

SC1204

SC1201

8

CN2

Main PWB

SC1202

P2006

CN3

P2003

8

SC2001

P701

P1601

8

Analog PWB

P3302

P3303

P4050

SC3403

P3704

8

P3404

8

P4001

P3201

P3703

Operation PWB

8

P6706

P6704

8

P6703

P6702

8

P6701

P6700

8

R/C, LED PWBWire Holder Inverter PWB

7

8

LC-20B5M

9. Remove the two lock screws from the operation panel (top cover), and detach the operation panel (top cover).

10. Remove the two lock screws from the operation PWB, and detach the operation PWB.

11. Remove the lock screw from the shield, and detach the shield from the main PWB.

12. Remove the two lock screws from the R/C, LED PWB, and detach the R/C, LED PWB.

13. Remove the two lock screws each from the speaker boxes (left and right), and detach both the speaker boxes.

9

13

Speaker Box (R)

Shield

R/C, LED PWB

Operation panel (Top Cover)

Operation
PWB

10

Analog PWB

13

Speaker Box (L)

Inverter PWB

12

9

LC-20B5M

14. Remove the two lock screws from the inverter PWB, and detach the inverter PWB.

15. Remo v e the fiv e loc k scre ws from the main PWB, and undo the cla ws a and b. Detach the main PWB by lifting the
area around the claws and pulling the PWB out.

16. Remove the one lock screw from the card frame cover over, and detach the card frame cover.

17. Remo v e the four lock screws from the analog PWB, and undo the claws c and d. Detach the chassis fr ame (right)
from the analog PWB by pulling out the terminals. In the same way, undo the claws e and f, and detach the
chassis frame (left) from the analog PWB by pulling out the terminals.

Note: When detaching the main PWB and analog PWB, be careful not to break the PWB-fixing claws.

18. Remove the one lock screw from the card LED PWB, and detach the card LED PWB.

17

16

Card Frame Cover

Card LED PWB

18

15

Main PWB

a

b

c

d

Chassis Frame (R)

15

Chassis Frame (L)

e

Analog PWB

14

f

Inverter PWB

10

» Precautions in handling the liquid crystal panel

Reflection Sheet (Top)
(PSHEPA103WJZZ)

Lamp Holder (Top)-B
(LHLDZA212WJKZ)

Lamp Unit Ass'y
(CLMP-A024WJ01)

Reflection Sheet (Bottom)
(PSHEPA104WJZZ)

Lamp Holder (Bottom)
(LHLDZA213WJKZ)

Back Shield
(PSLDMA312WJFW)

Lamp Holder (Top)-A
(LHLDZA211WJKZ)

Diffusion Sheet

(PSHEPA127WJZZ)
Reflection/Defelction
(PSHEPA101WJZZ)

Diffusion Plate
(PCOVUA014WJZZ)

Prism Sheet
(PSHEPA163WJZZ)

20" LCD Panel Unit

19

22

21

20

1. Handle it in a clean room. (above 50% humidity)

2. The worker must wear an earth band.

3. Be careful not to drop, vibrate and shock the panel.

4. Use an ionizer. (within 30 cm)

19. Remove the three lock screws from the liquid crystal panel, and detach the liquid crystal panel unit.

20. Remove the reflecting/polarizing sheet, prism sheet, diffusion sheet and diffusion plate.

21. Remove the lamp holder (top)-A, -B and the lamp holder (bottom) from the lamp unit assembly.

22. Remove the upper and lower reflection sheets from the back shield.

LC-20B5M

11

LC-20B5M

» Precautions in servicing the B side (backside) of the main PWB unit

1. Disconnect the FFC (flat cable) from between the main PWB (SC1204) and the liquid crystal panel, and then
connect the service-specific extension FFC (flat cable) (QCNW-A556WJZZ).

2. Disconnect the FFC (flat cable) from between the main PWB (SC1201) and the liquid crystal panel, and then
connect the service-specific extension FFC (flat cable) (QCNW-A555WJZZ).

3. Disconnect only the SC1202 of the FFC (flat cable) from between the main PWB (SC1202) and the liquid crystal
panel, and then connect the service-specific extension FFC (flat cable) (QCNW-B784WJZZ).

4. Disconnect the P701 side of the lead from between the main PWB (P701) and the analog PWB, and then
connect the service-specific extension cord (QCNW-C086WJQZ).

5. Disconnect the FFC from between the main PWB (SC2001) and the analog PWB (SC3403), and then connect
the service-specific extension FFC (flat cable) (QCNW-A556WJZZ).

6. Disconnect the lead from between the main PWB (P2006) and the analog PWB (P1601), and then connect the
service-specific extension cord (QCNW-C498WJQZ).

7. Remove the lock screws from the main PWB, detach the PWB from the chassis frame, and then turn it over to
service.

» Precautions in servicing the inverter PWB unit (backside)

8. Disconnect only the P3703 side of the lead from between the inverter PWB (P6706) and the analog PWB
(P3703), and then connect the service-specific extension cord (QCNW-C086WJQZ).

9. Remove the lock screws from the inverter PWB, detach the PWB (be careful not to get close to the high-tension
area and its surrounding conductive parts), and then turn it over to service.

Main PWB

(Side-B)

Main PWB Inverter PWB

CN2

7

CN3

3

SC1204

SC1202

P2006

6

SC1201

1

2

SC2001

P701

45

Inverter

PWB

(Side-B)

SC3403

P3201

P3703

8

P6706

P1601

Analog PWB

Step Part No. Description

1 QCNW-A556WJZZ Extension Cable 50-pin Main (SC2004)-LCD panel
2 QCNW-A555WJZZ Extension Cable 20-pin Main (SC1201)-LCD Panel
3 QCNW-B784WJZZ Extension Cable 30-pin Main (SC1202)-LCD Panel
4 QCNW-C086WJQZ Extension Cable 10-pin Main (P701)-Analog (P3201)
5 QCNW-A556WJZZ

Extension Cable 50-pin Main (SC2001)-Analog (SC3403)
6 QCNW-C498WJQZ Extension Cable 15-pin Main (P2006)-Analog (P1601)
8 QCNW-C086WJQZ Extension Cable 10-pin Main (P6706)-Analog (P3703)

9

12

LC-20B5M

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 exclusive-use AC adapter or stable DC power supply.

AC adapter: UADP-A063WJPZ (LC-20B5X)

UADP-A064WJPZ (LC-20B5M)

DC power supply: 12 ± 0.5V 5.6A

1. Adjustment Procedure

1-1. Adjusting the checker

Turning on the power (initialization) → Setting the model and size in inches → Transferring the model-specified
data to the E2PROM (I2C) → Calling the adjustment process mode → Starting the adjustment (+B adjustment)

1-2. Adjusting the finish process

Reassembling the set → Turning on the power → Calling the adjustment process mode (using the remote
controller) → Adjusting the counter bias, TV contrast and white balance

2. Calling the MAIN adjustment process mode

There are the following two ways to choose from.

• Set the Pin (81) (KEY4) or Pin (82) (KEY5) of IC2001 (microprocessor) to "L", turn on the power.

• For servicing, hold down the "TV/VIDEO" and "MENU" keys at once, and turn on the "POWER" switch. (Make
sure the process mode "K" appears at the top left of the screen.) Then press the "CH (Ù)" and "VOL (–)" keys
at once. (Make sure the adjustment process mode screen shows up.) To quit this mode, turn off the power. (Or
turn off the "POWER" switch or use the remote controller’s "OFF" key.)

3. Using the keys for the adjustment process

Selecting a reception channel

• Using the "CH (ù)/(Ù)" key, turn up and down reception (broadcasting) channels.
Just click on the key, and channels are selected on by one.
Hold down the key, and the next receivable channel is searched up and down.

• Adjustment items
Adjust each of the items by using the "MENU", "CURSOR UP/DOWN" and "VOL (+)/(–)" keys (on the set or on
the remote controller).

• Select an adjustment item using the "CURSOR UP/DOWN" key.

• An adjustment item is toggled on and off by activating the MENU SELECT key (next item).
Let’s suppose that the item at the bottom of a page is now selected. When the "MENU" key is activated here, the
item at the top of the next page will be selected.

4. Initialization

4-1. Set pins (81) and (82) of IC2001 (microprocessor) to GND. Turn on the power.
4-2. Select the inch size (20).
4-3. Select the model number "A642M".

~Once "A642M" has been selected, the screen shuts off and the power turns off. But the power turns

itself on to get the set restarted. (The microprocessor resets itself due to a change in model number.)

13

LC-20B5M

5. Adjustment

5-1. Counter bias adjustment: COM BIAS on page 2

Adjust the "COM BIAS" setting until the contrast gets optimum (the black portion blackest). The adjustment
guideline is around 100.

5-2. TAMP adjustment

1) Feed the colour bar pattern signal.

2) See if the "Y" reading on adjustment process page 2 is within the range shown below. If not, adjust the
"NTSC TAMP" setting to bring the "Y" reading within the specified range.

Model LC20B5M

Adjustment value 174~189

3) If the "NTSC TAMP" setting has been readjusted, write down its new setting in the "PAL TAMP" and
"SECAM TAMP" items manually.

(Page 2 of adjustment process 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

9
10
11
12

13

2

COM B I AS
TAMP L 71

YD TA
TAMP

NTSC TAMP
PAL TAMP 31
SECAM
RCUTOF

GCU TOF

BCU TOF
R – GAIN

G – GA IN

B – GAIN

A

H

TAMP
F
F

F

1

0
1

1. 0

00

4

815
819

31

3

1

3– 5
3– 2

1– 3

9.2

0.0
0

Y Data

(White 75%)

5-3. White balance adjustment

1) Feed the monoscope pattern signal.

2) Adjust the "RCUTOFF", "BCUTOFF", "R-GAIN" and "B-GAIN" settings on adjustment process page 3 to
achieve the colour at the same level as with the standard set.

14

LC-20B5M

5-4. Other adjustments (SOUND, VPC, DPS, DAC, TUNER, OTHERS, TEXT)

1) Move the cursor to a desired item on page 4 of adjustment process menu. Press the CURSOR LEFT/
RIGHT keys, "VOL (+)/(–)" keys or OK key to select the item.

4
I2C DATA 000000000000
I2C DATA WAIT
SOUND
VPC
DPS
DAC
TUNER
OTHERS
TEXT

2) The adjustment process menu of the item appears on the screen. The settings are now ready to change.

Screen with SOUND selected

SOUND1
VOLUME 0
AVC OFF
MSP DATA 0000000000
MSP DATA WAIT
0018H ST 1D
ONTA 1
CARRIER MUTE ON
SP TEST OFF

3) To go back to page 4 of adjustment process menu, press the FLASHBACK key on the remote controller.

15

LC-20B5M

6. Lamp error detection

6-1. 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 po wer 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.)

6-2. Countermeasures
6-2-1. 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 4, page 1 of the adjustment process is 1 or more. If it is 1
or more, it indicates the lamp error detection was executed.

6-2-2. 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 4, page 1 of the adjustment process and set the number to 0 using the volume button.

Page 1 of the adjustment process

1

M O D E L A642M
I N C H S I Z E 20
E R R O R N O R E S E T 5
P U B L I C M O D E OFF
E X T C O N T R O OFF
E X T M O D E UART
U P D A T E M O D E NORMAL
T E X T R E S E T OFF

V E R R O M 1. 0 0A G AI B U 0. 0 0 0

Reset 0

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

16

7. Public mode

• How to enter into PUBLIC MODE

1. Turn off TV by pressing MAIN POWER switch.

2. While pressing "MENU" key and "VOL(+)" key at the same time, press MAIN POWER switch for more than 2

seconds.
TV will turn on, and you will see the screen display setting pass word of PUBLIC MODE. (See Figure 1)

Figure 1

3. Press "0", "2", "7" key of Remote control, you wilt see the screendisplay a setting of PUBLIC MODE.

(See Figure 2)

• Setting screen of “PUBLIC MODE”

PUBLIC MODE
MAXIMUM VOLUME [ 60]
VOLUME FIXED [VARIABLE]
REMOTE CONTROL [RESPOND]
USER CONTROL [RESPOND]
MENU BUTTON [RESPOND]
ON SCREEN DISPLAY [YES ]
START MODE [NORMAL ]
INPUT MODE FIXED [NORMAL ]
SOUND ONLY MODE [NO ]
RESET
ENTER

1 ↔ 2 ··· ↔ 59 ↔ 60
VARIABLE ↔ FIXED
RESPOND ↔ LIMITED ↔ NO RESPOND
RESPOND ↔ NO RESPOND
RESPOND ↔ NO RESPOND
YES ↔ NO
NORMAL ↔ AV1 ↔ COMPONENT ↔ CH1 ↔ CH2
NORMAL ↔ FIXED
NO ↔ YES

↔ CH99 ↔ CH0

...

↔ CH98

LC-20B5M

Figure 2

Factory setting

Adjust setting

1. You can select each item of functions by pressing cursor UP/DOWN keys or CH(ù)/(Ù) Keys on the remote

control or CH(ù)/(Ù) keys on the LCD TV. The letter of selected item turns to yellow colour when you selected
it.

2. The setting position of each item of functions are made by pressing cursor RIGHT/LEFT keys on the remote

control or VOL (+)/(–)keys on the LCD TV.

3. Select ENTER position after you set all functions, and press cursor RIGHT/LEFT keys on the remote control

or VOL(+)/(–)keys on the LCD TV for confirmation.
Unless otherwise you make ENTER confirmation, the settings will not be memorized.

• 6-functions of Public Mode settings expand for public application

1. MAXIMUM VOLUME (1—————60)

You can set the maximum volume at your desire level.

2. VOLUME FIXED (VARIABLE / FIXED)

You can fix the sound volume at your desire level.
When you set to "FIXED", the sound volume which you just set is fixed.

3. REMOTE CONTROL (RESPOND / LIMITED)

If you set "LIMITED", remote control keys of POWER, CH(ù)/(Ù), VOL(–)/(+) and BRIGHT keys are
responded, but other keys are not responded.
This is a position that you can not make MENU adjustments.

4. USER CONTROL (RESPOND / NO RESPOND)

"NO RESPOND" means that the TV does not respond when you press a user control buttons except main
power button on the main unit.

17

LC-20B5M

5. MENU BUTTON (RESPOND / NO RESPOND)
With "NO RESPOND" selected, the remote controller and the set's MENU key are disabled.

6. ON SCREEN DISPLAY (YES / NO)
If you set "NO" position, OSD will not appear.

7. START MODE (NORMAL↔AV1↔COMPONENT↔CH1↔CH2
When any other item than "NORMAL" has been selected, the set gets started in the selected input mode or
channel at the next switch-on.

8. INPUT MODE FIXED (NORMAL↔FIXED)
(* This item cannot be selected if the start mode is "NORMAL".)
If "FIXED" has been selected, any channels and input modes other than those selected in the start mode cannot
be picked up.

9. SOUND ONLY MODE (NO↔YES)
(* This item cannot be selected if "NO" appears on the on-screen display.)
Let's suppose that this item has been selected and the BRIGHT key on the remote control has been pressed.
The item "BRIGHTNESS [OFF]" can now be selected next to the item "BRIGHTNESS [DARK]".

Screen with "BRIGHTNESS [OFF]" selected

...

↔CH98↔CH99↔CH0)

Count-down started from 5

BRIGHTNESS [OFF] TURNS OFF IN 5 SECS.

Five seconds later, the screen shuts off and the sound alone is heard.
Once in this mode, no picture but the OSD appears. But the channels and sound volume can still be changed.

To quit this mode, press the BRIGHT key on the remote control again and select any item other than
"BRIGHTNESS [OFF]".

10. RESET
You can cancel all Public Mode settings. (It returns to the factory setting.)

11. ENTER
You make sure after you have specified all functions, then press the enter key. Unless otherwise you press
the enter key, all positions that you have selected will not be set.

18

8. Functions of the PC card

8-1. Product outline

Sharp has adopted its original "ASV *2 method low-reflection black TFT flat panel" that can reproduce the
high-contrast images with firm black ev en in bright rooms . "QS technology" *1 reduces residual images even
for quick-moving subjects to realize eye-friendly images, and "I/P conversion for 3-D motions" suppresses
roughness and flickering. They help you watch the high-contrast and clear images from any angles.
Further more, this product is equipped with "PC card slot" to record TV programs on memory cards, and to
show the still images taken with digital cameras on the large screen of an LCD TV with memory cards*.
This model has new design that has side-speakers designed by Toshiyuki Kita, a world-known industrial
designer. The speak ers are punching metal-processed, so they ha ve a style sho wing quality sound capabilities.
The screen properties are, needless to say, much superior to CRT TV sets: lo w power consumption, long life
backlight, and other power-saving features, as well as reduced flickering.
* QS --> only for LC-20B5E (not available on LC-15B5E)
<CARD FUNCTIONS>

(1) Enjoying recorded TV programs

To record the program you are watching, all you need is just push the record button. Supporting the hard
disc PC cards newly realizes long-time recording. There are lots of recording functions*, including "Trace
Recording" (Going back to record to a fe w seconds before starting recording), "Reserved Recording" (Up
to 8 programs programmable a month) and "Easy Recording" (Finish time presettable during recording),
and you can enjoy the recorded programs on full screen.
* The video record system is MPEG-4. Smooth video with 25 frames/sec is realized.
(SD memory cards, Multimedia cards, Compact flashes, Smart media, Memory sticks, xD picture cards
and Micro drive are supported. For use , the PC card adapter specific for each memory card is necessary.
Names of memory cards are trademark.)

• EVideo Recording/Playing functions
One scene in the TV program you are watching can be recorded on memory cards. The recorded video
can be readily reproduced on demand. The Trace Recording function records from a few seconds before ,
so you need not worry about delaying the use of the remote controller. Three recording modes (SP/LP/
EP) are available for your applications.

LC-20B5M

Record mode Application Frame rate 256 MB card 5 GB card

Record time guideline

FINE 25

NORMAL

PORTABLE

Standard quality mode

Long time record mode

Portable device compatible mode

25

12.5

Approx. 10 min.
Approx. 30 min.

Approx. 1 hr.

Approx. 4 hrs.
Approx. 10 hrs.
Approx. 25 hrs.

* Record time is variable for the TV reception condition and the video contents.
* Ground-based broadcasting and external input (except for SCART RGB) that are not copy-protected can

be recorded.

* If the file capacity is over 4 GB, or the record time is longer than 12 hours , recording/pla ying is impossib le .

• EStill-Picture Recording/Playing functions

1) One scene in a TV program can be recorded on memory cards as a still image.

• EYou can readily record text information that you have made a memo until now.

Number of still images to be recorded

Recording size 32 MB card 128 MB card

Approx. 300

Approx. 1000

* The number of images is variable for the TV reception condition and the image contents.

2) Enjoying still images taken with digital cameras

With memory cards and on the large screen of an LCD TV, you can readily show still images captured
with digital cameras*.

* Only JPEG still images that were recorded to fit the standard (Design rule for Camera File system: DCF)

by Japan Electronics and Information Technology Industries Association Corp are playable.

* The number of files displayable is up to 1,024, including video and still images.

19

LC-20B5M

8-2. PC Card Unit Spec

(1) Still-Picture Mode

1) Recording/Play File Format Based on JPEG/DCF

2) Recording Pixcel Numbers 640x480

3) Playing Pixcel numbers 640x480

(2) Motion-picture Mode

1) File system ASF

(3) Motion picture Format

SP (Fine mode) MPEG4 QVGA (320x240) 2.5Mbps 25fps
LP (Normal Mode) MPEG4 QVGA (320x240) 1.0Mbps 25fps
EP (Portable Mode) MPEG4 QVGA (320x240) 384Kbps 12.5fps
Fitting Time Mode MPEG4 QVGA (320x240) Variable 25fps

(4) Audio Format

SP (Fine mode) WMA 2ch (Stereo) 32KHz 48Kbps
LP (Normal Mode) WMA 2ch (Stereo) 32KHz 48Kbps
EP (Portable Mode) G.726 1ch (monoral) 8KHz 32Kbps
Fitting Time Mode WMA 2ch (Stereo) 32KHz 48Kbps

Video Codec Picel Numbers Transfer Rate Frame Rate

Video Codec No. of Channel Sampling frequency Frame Rate

(5) Maximum file size

1) 1024 file (Still & Motion)

2) 4 GB

3) 12 hour

(6) Applicable Card media

HDD Card
Micro Drive
Compact Flash Card
Memory Stick/-DUO/-PRO
SD Card/mini SD
Multi media Card
xD Card

Smart Media

(7) PC Card Slot Interface 68pin PCMCIA

...

Max 5 GB

...

Max 2 GB

...

Max 2 GB

...

Max 128MB/1GB

...

Max 512/32MB

...

Max 128MB

...

Max 128MB

...

Max 128MB

20

8-3. Block diagram of card unit

MSP

DC/DC

converter

IC704

4V/6V

Reg

IC5409

3.3V/5V

DA150

IC5201

Audio DSP

Data bus

5V/3.3V conversion

IC5401-IC5406

PCMCIA

Card

DM270

(IC5001)

Video DSP

DSP

1.5V

64M SDRAM

IC5006

1.5V

Reg

IC5004

DC/DC

converter

3.3V

Video decoder

(VPC) IC8801

LCD

controller

TVCPU

8 bit video, CLK, H, V (ITU-R 656)

8 bit video, CLK, H, V (ITU-R 656)

UART

4V/6V switching signal

ON/OFF

16 bit address

16 bit data

I

2

S (for recording)

I

2

S (for playing)

PC card block Main

32M FLASH

IC5003

LC-20B5M

21

LC-20B5M

• PCMCIA card Used at 5V/3.3V

• DM270 (IC5001) CPU, DSP, DMA C, OSD, NTSC encoder: system control, OSD display, video encoding/decoding

Used at 3.3V (1.5V for DSP)

• DA150 (IC5201) Audio encoding/decoding

• 32M FLASH (IC5003) Storing the program for DA150 and DM270

• 64M SDRAM (IC5006) Used for temporary data storage and for image data compression and expansion.

• Reg (IC5409) Conversing 4V/6V to 3.3V/5V for PCMCIA

• Reg (IC5004) Conversing 3.3V to 1.5V for DSP in DM270

"Tips"

1) With this product, showing images recorded with PC or DSC enables you to check the playing system.

2) With PC, showing images recorded with this product enables you to check the recording system.

3) Video is played at the rate in sync with IIS CLOCK signals from audio circuit. For example, if the IIS CLOCK
signals fail to reach the card playing circuit f or some reason, the video is pla y ed at the lo west r ate and is shown
in slow motion.

Major input/output terminals on the card system

Card side
IC (connector) Pin No. LSI terminal name Connection diagram Types of signals Explanation for signals I/O
name signal name
DM270 B3.3V_CARD1A B3.3V_CARD1A Power supply Power supply 3.3V for DM270 I
(IC5001)

103 VIN VIN V signal from VPC to DM270 I
102 HIN HIN H signal from VPC to DM270 I
100 LLC2 (CLK) LLC2 Clock signal from VPC to DM270 I
112 YIN0 YIN0 Data signal 0 from VPC to DM270 I
111 YIN1 YIN1 Data signal 1 from VPC to DM270 I
110 YIN2 YIN2 Video input/output Data signal 2 from VPC to DM270 I
109 YIN3 YIN3 Data signal 3 from VPC to DM270 I
108 YIN4 YIN4 Data signal 4 from VPC to DM270 I
107 YIN5 YIN5 Data signal 5 from VPC to DM270 I
106 YIN6 YIN6 Data signal 6 from VPC to DM270 I
105 YIN7 YIN7 Data signal 7 from VPC to DM270 I

55 RESET RESET Data Reset signal from TV microprocessor to DM270 I
10 CA_DOUT DOUT communication Data signal from TV microprocessor to DM270 I
11 DIN DIN Data signal from DM270 to TV microprocessor I
70 VOUT VOUT V signal from DM270 to IP O
69 HOUT HOUT H signal from DM270 to IP O
68 CKOUT CKOUT Clock signal from DM270 to IP O
81 YOUT0 YOUT0 Data signal 0 from DM270 to IP O
77 YOUT1 YOUT1 Data signal 1 from DM270 to IP O
76 YOUT2 YOUT2 Video input/output Data signal 2 from DM270 to IP O
75 YOUT3 YOUT3 Data signal 3 from DM270 to IP O
74 YOUT4 YOUT4 Data signal 4 from DM270 to IP O
73 YOUT5 YOUT5 Data signal 5 from DM270 to IP O
72 YOUT6 YOUT6 Data signal 6 from DM270 to IP O
71 YOUT7 YOUT7 Data signal 7 from DM270 to IP O

P5003 1 I2S_WS S_WS I2S word strobe L: Right audio input / H: Left audio input I

2 GND
3 I2S_CL S_CL Clock for I2S serial data transmission timing I
4 GND
5 I2SDA_OUT S_DO Audio input/output Audio data input from TV main unit I
6 GND
7 I2SDA_IN1 S_DI In card mode: Card Audio / Not in card mode: Shutter sound O
8 GND
9 I2SDA_IN2 SH_DI

10 GND

Reg 1 IN B4V/6V1_1A 4V/6V output from DC/DC converter to Reg O
(IC5409) 2 SW B4V/6V1_1A ON/OFF switch I

3 OUT V5EN Power supply 3V power input from DC/DC converter to Reg I

V3EN 5V power input from DC/DC converter to Reg I
4 ADJ For adjustment
5 GND GND GND

22

LC-20B5M

Main Side
IC (connector) Pin No. Terminal name Signal name Types of signals Explanation for signals I/O
name
P701 9 3.3V (SUB) B3.3V2A Power supply Power supply 3.3V for DM270
(NA215WJ)

VPC 57 VS VPC_VS V signal from VPC to DM270 O
(Video decoder) 56 MSY/HS VPC_HS H signal from VPC to DM270 O
IC8801 27 LLC2 LLC2 Clock signal from VPC to DM270 O

40 Y0 VPC_YIN0 Data signal 0 from VPC to DM270 O
39 Y1 VPC_YIN1 Data signal 1 from VPC to DM270 O
38 Y2 VPC_YIN2 Video input/output Data signal 2 from VPC to DM270 O
37 Y3 VPC_YIN3 Data signal 3 from VPC to DM270 O
34 Y4 VPC_YIN4 Data signal 4 from VPC to DM270 O
33 Y5 VPC_YIN5 Data signal 5 from VPC to DM270 O
32 Y6 VPC_YIN6 Data signal 6 from VPC to DM270 O
31 Y7 VPC_YIN7 Data signal 7 from VPC to DM270 O

TV 83 CARDRST RESET
microprocessor 35 SUB_DOUT DOUT Rese
(IC2201) 36 SUB_DIN DIN Data signal from DM270 to TV microprocessor I
I/P conversion 207 VS_P2 VD_VS V signal from DM270 to IP I
IC 208 HS_P2 VD_HS H signal from DM270 to IP I

195 IN_CLK_P2 VD_CKO Clock signal from DM270 to IP I
196 P2_0 VPC_0 Data signal 0 from DM270 to IP I
199 P2_1 VPC_1 Data signal 1 from DM270 to IP I
200 P2_2 VPC_2 Video input/output Data signal 2 from DM270 to IP I
201 P2_3 VPC_3 Data signal 3 from DM270 to IP I
202 P2_4 VPC_4 Data signal 4 from DM270 to IP I
203 P2_5 VPC_5 Data signal 5 from DM270 to IP I
204 P2_6 VPC_6 Data signal 6 from DM270 to IP I
205 P2_7 VPC_7 Data signal 7 from DM270 to IP I

MSP 5 I2S_WS S_WS I2S word strobe L: Right audio input / H: Left audio input O
(

Audio processor

DC/DC
converter B4V/6V1_1A B4V/6V1_1A Power supply 4V/6V output from DC/DC converter to Reg O
IC704

)

4 I2S_CL S_CL Clock for I2S serial data transmission timing O

6 I2SDA_OUT S_DO Audio input/output Audio data input from TV main unit O

7 I2SDA_IN1 S_DI In card mode: Card Audio / Not in card mode: Shutter sound I

Data communication,

t

Reset signal from TV microprocessor to DM270 O
Data signal from TV microprocessor to DM270 O

Abolished

23

LC-20B5M

No picture and sound

Check all the settings on the microprocessor'fs adjust process menu.

Fluorescent light in trouble

Are F3701 and F3702 normal?

YES

YES

YES

YES

YES

YES

NO

NO

NO

NO

NO

NO

YES

YES

NO

Does the load side keep

normal circuits when F3701

and F3702 are disconnected?

Are F3701, F3702, F6700,

F6701, F6702, F6703 and

F6704 normal?

Do Q6702, Q6705, Q6708,

Q6711 and Q6714 keep

normal circuits?

Check Q6702, Q6705, Q6708,

Q6711, Q6714 and their

peripheral circuits.

Check S4053 and the

connecting cables.

Check the connecting cables

and the peripheral circuits of

J3701.

Are pins (10) and (11) of

IC1201"H"?

Are the oscillation waves from

the primary sides of T6700

thru T6709 normal?

Check and replace the

fluorescent light.

Check the connecting cables

and the peripheral circuits of

Q6700 thru Q6713.

Check that line, IC1201 and

their peripheral circuits.

Are +34V, +9V and +5V on the

secondary side output at T701

normal?

Are +35V, +9V and +5V on

the secondary side output at

T701 normal?

Are pins (14) of IC702 thru

IC707 normal? (1.35V-2.05V)

Check the load side.

Do Q716, S4053 and the

peripheral circuits on the

primary side of T3701 keep

normal circuits?

Replace F3701 and F3702.

TROUBLE SHOOTING TABLE

24

No picture (1/2)

No picture at all

No TV , VIDEO 1, VIDEO 2

and VIDEO 3 outputs

No TV output

No VIDEO 1 output

No VIDEO 2 output

Check all the settings on the microprocessor'fs adjust process menu.

NO

NO

NO NO NO NO

NO

NO

NO

NO

NO

NO

YES YES

YES

YES YES

No S-VIDEO output

No COMPONENT output

YES

YES

YES

YES

No picture (2/2)

No PC card output

Check all the settings on the microprocessorÅfs adjust process menu.

NO

NO

NO

NO

YES

YES

YES

YES

Are the

input/output

at IC8801

normal?

Are the

input/output

at IC3401

normal?

Check

IC3401 and

its peripheral

circuits.

Check the

power supply

line.

Is the input

at pin (1) of

IC3401

normal?

Is the input

at pin (8) of

IC3401

normal?

Is the input at pins

(71) and (72) of

IC8801 normal?

Is the input at pins (4), (5),

(6) and (75) of IC8801

normal? (D1)

Is the input at pins (43),

(48) and (54) of IC8701

normal? (D2)

Check the DVD_Y, CB and

CR lines of J2205 and their

peripheral circuits.

Check the SY and SC

lines of J3401 and

their peripheral

circuits.

Is the output

at IC3401

normal?

Is the output

at IC3401

normal?

Check

IC3401 and

its peripheral

circuits.

Check

IC3401 and

its peripheral

circuits.

Check that

line.

Check that

line.

Is the voltage

at pins (6),

(7) and (9) of

the tuner

normal?

Is the output

at pin (19) of

the tuner

normal?

Is the input

at pin (47) of

IC3401

normal?

Is the output

at IC3401

normal?

Check that

line.

Check

IC3401 and

its peripheral

circuits.

Are the card

medium and its files

normal?

Check the

medium and

its files.

Is the output at

IC8602 and IC8603

normal?

Check that

line.

Replace the card

unit.

Is the voltage at

pins (2) and (3) of

P5001 in the PC

card unit normal?

Check the

power supply

line.

Is the voltage at

pins (1), (2) and (3)

of IC5004 and at

pins (1), (2) and (3)

of IC5005 normal?

Check the

power supply

line.

Check the

tuner and its

peripheral

circuits.

Check that

line.

Is the input

at pin (73)

of IC8801

normal?

Check the

AV1 line of

IC8801 and

its peripheral

circuits.

Are the

input/output

at IC1201

normal?

Check the voltage and

waves at the liquid

crystal panel.

Check

IC1201 and

its peripheral

circuits.

Check

IC8801 and

its peripheral

circuits.

Are inputs

and outputs

of Q1602,

Q1604 and

Q1606 as

specified?

Check

Q1602,

Q1604,

Q1606 and

its

peripheral

parts.

Is output at

pins

(57)~(59) of

IC1601

normal?

Check the

R, G and B

line.

Is input at

pin (21) of

IC1601

normal?

Check V2V0

line and its

peripheral

parts.

Check

IC1601 and

its

peripheral

parts.

No TELE TEXToutput

No

Yes

Yes

No

No

Yes

TROUBLE SHOOTING TABLE (Continued)

LC-20B5M

25

LC-20B5M

No sound

No sound from speakers

YES

YES

YES

YES

YES

YES

NO

YES

YES

YES

YES

NO

NO

NO

NO

NO

NO

NO

NO

NO

Check the following.

1 No audio output from TV ... Check the

peripheral circuits of Q3202 and TU3000.

2 No audio output from VIDEO 1 input ...

Check J3402 thru pins (2) and (4) of

IC3401.

3 No audio output from VIDEO 2 input ...

Check J3409 thru pins (22) and (24) of

IC3401.

4 No audio output from VIDEO 3 input ...

Check J3403 thru pins (9) and (11) of

IC3401.

5 No audio output from COMPONENT input ...

Check J3406 and J3404 thru pins (46) and

(48) of IC3401.

Is there the audio output in any input mode (TV, VIDEO 1/2

and COMPONENT)?

Check the following.

1

Is the monitor output setting at "Audio fixed"?

2

Is the sound volume loud enough?

3

Is the mute mode released?

4

Are the headphones unplugged?

Is the power supply voltage at each circuit normal?

Pin (8) of IC3301 and pin (39) of IC3201 Approx. +8V

Pins (11), (12), (13), (65) and (66) of IC3201 Approx. +5V

No sound from monitor output

Is there the audio signal output at pins (33)(Rch) and

(34)(Lch) of IC3201?

Is pin (58) of IC2001 "H"?

Is the signal from the Q2203 collector "L"?

Check pins (33)(Rch) and (34)(Lch) of IC3201 thru pins

(4)(Lch) and (2)(Rch) of J3404.

Check the following.

1

Is there the audio output from speakers?

2

Is the monitor output connected correctly?

3

Is the mute mode released?

Check the following.

1

Go to "No Audio from Speakers"h.

2

Connect the monitor output correctly.

3

Release the mute mode.

Check the peripheral circuits of IC3201.

Check pin (4) of J4021 thru pin (58) of

IC2001.

Check pin (55) of IC2001 thru Q2203, and

Q2201.

Is there the control signal input at each pin of IC3201?

Pin (2) of IC3201 SCL1

Pin (3) of IC3201 SDA1

Are the oscillation waves from pins (71) and (72) of IC3201

normal?

Check pins (29) and (30) of IC2001 thru pins (2)

and (3) of IC3201.

Check the peripheral circuits of X3201.

Is there the audio signal output at pins (27)(Rch) and

(28)(Lch) of IC3201?

Check pins (27)(Rch) and (28)(Lch) of IC3201 thru pins

(7)(Rch) and (1)(Lch) of IC3301, and the peripheral circuits

of IC3301 and IC3303.

Check the peripheral circuits of IC3201.

Recheck the following.

1

Set the monitor output to "Audio fixed".

2

Increase the sound volume.

3

Release the mute mode.

4

Unplug the headphones.

Check the following.

+8V system ... Check the peripheral circuits of

Q3711 thru pin (8) of IC3301 and

pin (39) of IC3201.

+5V system ... Check the T701 output B5V500MA

line thru each +5V input pin of

IC3201.

TROUBLE SHOOTING TABLE (Continued)

26

TROUBLE SHOOTING TABLE (Continued)

No Colours

No TV colours No VIDEO colours

No S-VIDEO colours

No COMPONENT colours

Check all the settings on the microprocessor's adjust process menu.

YES

NO

NO

Is the input at pin (71) of

IC8801 normal?

Is the input at pins (4) and

(6) of IC8801 normal? (D1)

Is the input at pins (43) and

(54) of IC8701 normal?

(D2)

Check the CB and CR

lines of J2205 and their

peripheral circuits.

Check the output at

IC8801 (D1), output at

IC8701 (D2), input/output

at IC1201 and their

peripheral circuits.

Check the SC line of J2201

and its peripheral circuits.

LC-20B5M

27

LC-20B5M

CHASSIS LAYOUT

H

G

F

OPERATION Unit

ANALOG UnitMain Unit

INVERTER Unit

E

D

C

B

CARD LED Unit

R/C, LED Unit

A

121110987654321

28

29