Panasonic TC-L42S20BL Schematic

ORDER NO. PBRAS1103078CE

Service Manual

LCD TV

TC-L42S20BL

Chassis: KM09W

• Design and specications are subject to change without notice. Mass and dimensions shown are approximate.

© 2010 Panasonic do Brasil Limitada
CS Division
Technical Support

TC-L42S20BL

CONTENTS

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

1.1. General Guidelines ...........................................................................3

1.1.1. Leakage Current Cold Check ........................................................ 3

1.1.2. Leakage Current Hot Check (See Figure1.) .................................. 3

2 Warning ................................................................................................4

2.1. Prevention of Electrostatic Discharge (ESD)

to Electrostatically Sensitive (ES) Devices .............................................. 4

2.2. About lead free solder (PbF).............................................................5

3 Service Navigation................................................................................6

3.1. Service Hint .....................................................................................6

4 Specications .......................................................................................7

5 Service Mode........................................................................................8

5.1. How to enter into Service Mode .......................................................8

5.1.1. Contents of adjustment mode........................................................8

5.1.2. How to exit .....................................................................................8

5.2. SRV-TOOL ........................................................................................9

5.2.1. How to access ...............................................................................9

5.2.2. Display of SOS History .................................................................. 9

5.2.3. POWER ON TIME/COUNT ........................................................... 9

5.2.4. Exit.................................................................................................9

5.3. Service Mode Adjustment .................................................................10

5.3.1. Self Check Mode ........................................................................... 10

5.3.2. Hotel Mode Adjustment ................................................................. 10

5.3.3. Hotel Mode ....................................................................................10

6 Troubleshooting Guide .........................................................................11

6.1. Check of the IIC bus lines.................................................................11

6.1.1. How to access ...............................................................................11

6.1.2. Exit.................................................................................................11

6.1.3. Screen display ............................................................................... 11

6.1.4. Check Point ...................................................................................11

6.2. Power LED Blinking timing chart ...................................................... 12

6.3. No Power ..........................................................................................12

7 Disassembly and Assembly Instructions .............................................. 13

7.1. AC Cord Dressing .............................................................................13

7.2. AC Cord Installation ..........................................................................14

7.3. Control Panel Assembly & Clamper Installation ............................... 15

7.4. Side AV Preparation & Installation .................................................... 16

7.5. Speaker Preparation & Installation ................................................... 17

7.6. LCD Panel Assembly Installation......................................................18

7.7. LED Panel Installation ...................................................................... 19

7.8. Felt Sticking at LVDS Wire ............................................................... 20

7.9. LCD Bracket and MTG Installation .................................................. 21

7.10. Pedestal Assembly ......................................................................... 22

8 Measurements and Adjustments .......................................................... 24

8.1. Voltage chart of A-board ................................................................... 24

8.2. Voltage chart of P-board ...................................................................24

9 Block Diagram ...................................................................................... 25

9.1. Main Block Diagram .........................................................................25

10 Wiring Connection Diagram................................................................26

11 Schematic Diagram ............................................................................ 27

11.1. Schematic Diagram Notes ..............................................................27

11.2. A Board ........................................................................................... 28

11.2.1. A Board - Sheet : 002 (1 / 3) ........................................................ 28

11.2.4. A Board - Sheet : 010 (1 / 3) ........................................................ 31

11.2.7. A Board - Sheet : 011 (1 / 3) ........................................................34

11.2.10. A Board - Sheet : 012 (1 / 3) ...................................................... 37

11.2.13. A Board - Sheet : 020 (1 / 3) ...................................................... 40

11.2.16. A Board - Sheet : 031 (1 / 3) ...................................................... 43

11.2.19. A Board - Sheet : 033 (1 / 2) ...................................................... 46

11.2.21. A Board - Sheet : 040 (1 / 5) ...................................................... 48

11.2.26. A Board - Sheet : 050 (1 / 2) ...................................................... 53

11.2.28. A Board - Sheet : 060 (1 / 2) ...................................................... 55

11.2.30. A Board - Sheet : 061 (1 / 1) ...................................................... 57

11.2.31. A Board - Sheet : 090 (1 / 3) ...................................................... 58

11.2.34. A Board - Sheet : 201 (1 / 3) ...................................................... 61

11.2.37. A Board - Sheet : 300 (1 / 4) ...................................................... 64

11.2.41. A Board - Sheet : 700 (1 / 2) ...................................................... 68

11.2.43. A Board - Sheet : 701 (1 / 2) ...................................................... 70

11.3. K Board ...........................................................................................72

11.4. P Board ........................................................................................... 74

11.5. V Board ...........................................................................................77

12 Printed Circuit Board ..........................................................................80

12.1. A-Board...........................................................................................80

12.2. A-Board...........................................................................................81

12.3. P-Board ..........................................................................................82

12.4. P-Board ..........................................................................................83

13 Exploded View and Replacement Parts List .......................................84

13.1. Exploded View and Mechanical Replacement Parts List ...............84

13.2. Electrical Replacement Parts List ...................................................84

13.2.1. Replacement Parts List Notes ..................................................... 84

13.2.2. Mechanical Parts Location ..........................................................85

13.2.3. Mechanical Replacement Parts List ............................................ 85

13.2.4. Assembled Boards.......................................................................85

13.2.5 Packing Exploded View 1 ............................................................. 86

13.2.6. Packing Exploded View 2 ............................................................ 87

13.2.7. Electrical Replacement Parts List ................................................88

2

TC-L42S20BL

1 Safety Precautions

1.1. General Guidelines

1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or
damaged by the short circuit.

2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.

3. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.

4. When conducting repairs and servicing, do not attempt to modify the equipment, its parts or its materials.

5. When wiring units (with cables, flexible cables or lead wires) are supplied as repair parts and only one wire or some of the
wires have been broken or disconnected, do not attempt to repair or re-wire the units. Replace the entire wiring unit instead.

6. When conducting repairs and servicing, do not twist the Faston connectors but plug them straight in or unplug them straight
out.

1.1.1. Leakage Current Cold Check

1. Unplug the AC cord and connect a jumper between the
two prongs on the plug.

2. Measure the resistance value, with an ohmmeter,
between the jumpered AC plug and each exposed
metallic cabinet part on the equipment such as
screwheads, connectors, control shafts, etc. When the
exposed metallic part has a return path to the chassis, the
reading should be 100 Mohm and over.
When the exposed metal does not have a return path to
the chassis, the reading must be .

1.1.2. Leakage Current Hot Check (See
Figure 1.)

1. Plug the AC cord directly into the AC outlet. Do not use
an isolation transformer for this check.

2. Connect a 1.5kohm, 10 watts resistor, in parallel with a

0.15μF capacitors, between each exposed metallic part
on the set and a good earth ground such as a water pipe,
as shown in Figure 1.

3. Use an AC voltmeter, with 1000 ohms/volt or more
sensitivity, to measure the potential across the resistor.

4. Check each exposed metallic part, and measure the
voltage at each point.

5. Reverse the AC plug in the AC outlet and repeat each of
the above measurements.

6. The potential at any point should not exceed 0.75 volts
RMS. A leakage current tester (Simpson Model 229 or
equivalent) may be used to make the hot checks, leakage
current must not exceed 1/2 milliamp. In case a
measurement is outside of the limits specified, there is a
possibility of a shock hazard, and the equipment should
be repaired and rechecked before it is returned to the
customer.

Figure 1

3

TC-L42S20BL

2 Warning

2.1. Prevention of Electrostatic Discharge (ESD) to Electrostatically
Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and
semiconductor [chip] components. The following techniques should be used to help reduce the incidence of component damage
caused by electrostatic discharge (ESD).

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your
body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
which should be removed for potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified as [anti-static (ESD protected)] can
generate electrical charge sufficient to damage ES devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or
comparable conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be installed.

Caution

Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise ham less motion such as the
brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD)
sufficient to damage an ES device).

4

TC-L42S20BL

2.2. About lead free solder (PbF)

Note: Lead is listed as (Pb) in the periodic table of elements.
In the information below, Pb will refer to Lead solder, and PbF will refer to Lead Free Solder.
The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu).
That is Tin (Sn), Silver (Ag) and Copper (Cu) although other types are available.

This model uses Pb Free solder in it’s manufacture due to environmental conservation issues. For service and repair work, we’d
suggest the use of Pb free solder as well, although Pb solder may be used.

PCBs manufactured using lead free solder will have the PbF within a leaf Symbol PbF stamped on the back of PCB.

Caution

• Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70 °F (30~40 °C) higher. Please
use a high temperature soldering iron and set it to 700 ± 20 °F (370 ± 10 °C).

• Pb free solder will tend to splash when heated too high (about 1100 °F or 600 °C).
If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before applying Pb
solder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.

• After applying PbF solder to double layered boards, please check the component side for excess solder which may flow onto the

opposite side. (see figure below)

Suggested Pb free solder

There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder.
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used.

5

TC-L42S20BL

3 Service Navigation

3.1. Service Hint

Board Main Device

A BOARD AVSW, TUN, OFDM, ADV, P-AVC, GENX, EEP, TEMP

P BOARD Power Supply

V BOARD Remote, LED, Luminunce Sensor

K BOARD KEY, Power SW

TC BOARD T-CON Board

6

4 Specications

TC-L42S20BL

TC-L42S20A / TC-L42S20P / TC-L42S20BL

Alimentación

Promedio
Condición en espera

Consumo

Aspecto

Tamaño visible de la pantalla

pantallasonido

Número de pixels
Altavoz
Salida de audio
Auriculares

Señales de computadora

Sistema de recepción/Nombre
de la banda

Canales de recepción

(TV Nor mal)

Antena - Trasera
Condiciones de operación

Entrada AUDIO L - R
AV1

Entrada AUDIO L - R
AV2

Entrada AUDIO L - R
AV3

Salida AUDIO L - R
Monitor

Terminales de conexión

Otros Entrada HDMI1/2/3

Dimensiones (L × A × P)

Peso

VIDEO
COMPONENT

VIDEO

VIDEO

VIDEO

Entrada PC

Entrada de tarjeta
Entrada USB

110-220 V ~ 50/60 Hz

193 W
0,4 W
16:9

106 cm (diagonal)

930 mm (L) × 523 mm (A)

2.073.600 (1.980 (L) × 1.080 (A)

160 mm × 42 mm × 2 pçs, 8 Ω

20 W (10 W + 10 W), 10% THD

M3 (3,5 mm) mini jack estéreo ×1

VGA, SVGA, XGA

SXGA ..... (comprimido)

Frecuencia de lectura horizontal 31 - 69 kHz
Frecuencia de lectura vertical 59 - 86 Hz

1. PAL-M

2. PAL-N

3. NTSC

BANDA VHF BANDA UHF CATV

2-13 (NTSC M EUA) 14-69 (NTSC M EUA) 1-125 (EUA CATV)

VHF / UHF

Temperatura: 0°C - 40°C
Humedad: 20% - 80% HR (sin condensación)

Tipo RCA PIN ×2 0,5 V[rms]

Tipo RCA PIN ×1 1,0 V[p-p] (75 Ω)

Y 1,0 V[p-p] (incluyendo sincronía)
PB/CB, PR/CR ±0,35 V[p-p]

Tipo RCA PIN ×2 0,5 V[rms]

Tipo RCA PIN ×1 1,0 V[p-p] (75 Ω)

Tipo RCA PIN ×2 0,5 V[rms]

Tipo RCA PIN ×1 1,0 V[p-p] (75 Ω)

Tipo RCA PIN ×2 0,5 V[rms] (alta impedáncia)

Tipo RCA PIN ×1 1,0 V[p-p] (75 Ω)
Conectores Tipo A • Este TV soporta la función “HDAVI Control 5”

HIGH-DENSITY D-SUB 15 PINES

Entrada SD CARD ×1

USB 2.0 conector Tipo A ×1, 5V DC, 500 mA máx.

1021 mm × 680 mm × 310 mm (con pedestal)
1021 mm × 637 mm × 115 mm (solamente TV)

21,0 kg (con pedestal)
18,0 kg (solamente TV)

Recepción de transmisión y reproducción en videocasete o DVD

R, G, B/0,7 V [p-p] (75 Ω)
HD, VD/TTL Nível 2,0 - 5,0 V[p-p] (alta impedáncia)

7

TC-L42S20BL

5 Service Mode

5.1. How to enter into Service Mode

While pressing [VOLUME ( - )] button of the main unit, press [INFO] button of the remote control three times within 2 seconds.

5.1.1. Contents of adjustment mode

• Value is shown as a hexadecimal number.

• Preset value differs depending on models.

• After entering the adjustment mode, take note of the value in each item before starting adjustment.

Main item Sub item Sample Data Remark

ADJUST CONTRAST 000

COLOR 4C

TINT 00

SUB-BRT 808

BACKLGT 22E

B-Y-G 34

R-Y-A 00

WB-ADJ R-GAIN F7

G-GAIN FB

B-GAIN DB

R-CENT 82

G-CENT 80

B-CENT 86

OPTION Boot ROM Factory Preset.

STBY-SET 00

EMERGENCY ON

CLK MODE 00

CLOCK 0E4

RM-SET 00 Fixed.

SRV-TOOL 00 See next.

5.1.2. How to exit

Switch off the power with the [POWER] button on the main unit or the [POWER] button on the remote control.

8

TC-L42S20BL

5.2. SRV-TOOL

5.2.1. How to access

1. Select [SRV-TOOL] in Service Mode.

2. Press [OK] button on the remote control.

5.2.2. Display of SOS History

SOS History (Number of LED blinking ) indication.
From left side; Last SOS, before Last, three occurrence before, 2nd occurrence after shipment, 1st occurrence after shipment.
This indication except 2nd and 1st occurrence after shipment will be cleared by [Self-check indication and forced to factory
shipment setting].

5.2.3. POWER ON TIME/COUNT

Note : To display TIME/COUNT menu, highlight position, then press MUTE for 3sec.
Time : Cumulative power on time, indicated hour : minute by decimal
Count : Number of ON times by decimal
Note : This indication will not be cleared by either of the self-checks or any other command.

5.2.4. Exit

1. Disconnect the AC cord from wall outlet.

9

TC-L42S20BL

5.3. Service Mode Adjustment

Set timer to 30min, press the ‘RECALL’ button on the remote control and press ‘-’ vol button on the LCD panel.

• Press button R and G for adjustment.

5.3.1. Self Check Mode

1. Press the ‘MENU’ button (on the remote control) and the ‘DOWN’ button on the LCD panel.

2. Press ON/OFF button on the panel to Exit.

5.3.2. Hotel Mode Adjustment

1. Press the ‘VOLUME DOWN’ button on the TV panel and simultaneously press the AV button on the remote control 3 times to
enter Hotel Mode.

2. Set Hotel mode ‘on/off’, then press ‘EXIT’ to come out.

5.3.3. Hotel Mode

1. Purpose
Restrict a function for hotels.

2. Access command to the Hotel mode setup menu.
In order to display the Hotel mode setup menu, please
enter the following command (within 2 second).
[TV] : Hold Vol [Down] + [Remote] : Press AV button 3
times.

Then, the Hotel mode setup menu is displayed.

Item Function

Hotel Mode Select hotel mode ON/OFF

Initial INPUT Select input signal modes.

Set the input, when each time power is switched
on.
Selection :
OFF/Analogue TV/Digital TV/AV1/AV2/AV3/PC/
HDMI1/HDMI2/HDMI3

• Off: give priority to a last memory.

• Selectable input is depend on the model.

Initial POS Select programme number.

Initial VOL level Adjust the volume when each time power is

Maximum VOL
level

Button lock Select local key conditions.

Remote lock Select remote control key conditions.

Selection :
Off/0 to 100

• Off: give priority to a last memory.

switched on.
Selection/Range :
Off/0 to 100

• Off: give priority to a last memory.

Adjust maximum volume.
Range :
0 to 100

Selection :
Off/SETUP/MENU/All

• Off: altogether valid.

• SETUP: only F-key is invalid.
(Tuning guide (menu) can not be selected.)

• MENU: only F-key is invalid.
(only Volume/Mute can be selected.)

• ALL: altogether invalid.

Selection :
Off/SETUP/MENU

• Off: altogether valid.

• SETUP: only Setup menu is invalid.

• MENU: Picture/Sound/Setup menu are invalid.

10

TC-L42S20BL

6 Troubleshooting Guide

Use the self-check function to test the unit.

1. Checking the IIC bus lines

2. Power LED Blinking timing

6.1. Check of the IIC bus lines

6.1.1. How to access

Self-check indication only:
Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [OK] button on the remote control
for more than 3 seconds.
Self-check indication and forced to factory shipment setting:
Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [MENU] button on the remote
control for more than 3 seconds.

6.1.2. Exit

Disconnect the AC cord from wall outlet.

6.1.3. Screen display

6.1.4. Check Point

Confirm the following parts if NG was displayed.

11

TC-L42S20BL

6.2. Power LED Blinking timing chart

1. Subject
Information of LED Flashing timing chart.

2. Contents
When an abnormality occurs, the protection circuit will operate and reset the unit to stand by mode. During this time, the
defective block can be identified by the number of blinking times of the Power LED on the front panel of the unit as follow:

Blinking times Contents BOARD

1 Inverter_SOS P BOARD

2 FAN_SOS A BOARD

3 SOS A BOARD

4 DTV_9V P/A BOARD

5 MAIN_9V A BOARD

6 SUB_5V A BOARD

7 SUB_3.3V A BOARD

8 MAIN_3.3V A BOARD

9 SOUND_SOS A BOARD

10 HQ1L_SOS / ZWEI_SOS A BOARD

13 EMERGENCY SOS A BOARD

14 Audio PWM SOS A BOARD

6.3. No Power

First check point
There are following 2 states of No Power indication by power LED.

1. No lit

2. Red is lit then turns red blinking a few seconds later. (See 6.2.)

12

7 Disassembly and Assembly Instructions

7.1. AC Cord Dressing

1. Clamp plug with clamper.

2. Insert beads 3 pcs. And slide down to lower hole.

TC-L42S20BL

13

TC-L42S20BL

7.2. AC Cord Installation

1. Put on the AC CORD BRACKET on the CABINET.

2. Fix the AC CORD BRACKET with SCREW.

3. Insert AC CORD connector into P-PCB connector.

4. Clamp the AC CORD.

5. Insert AC CORD bushing into the AC CORD BRACKET.

6. AC CORD is pushed into the bottom of the bracket.

14

7.3. Control Panel Assembly & Clamper Installation

1. Put control panel Assy on the cabinet.

2. Fix the control panel with screws.

TC-L42S20BL

Fix clamper at bottom mtg.

15

TC-L42S20BL

7.4. Side AV Preparation & Installation

1. Stick the side av indi. Sheet and felt on the side av bracket.

2. Insert the SIDE AV BRACKET from the side position of the A-PCB.

3. Fix the SCREW with A-PB-MTG METAL.

16

7.5. Speaker Preparation & Installation

1. Stick the SP sponge.

2. SP bracket put on cabinet.

3. Fix them with screws.

4. Insert the SP rubber bush into the SP unit.

5. Stick sponge at speaker.

6. Insert the SP unit to SP bracket.

TC-L42S20BL

17

TC-L42S20BL

7.6. LCD Panel Assembly Installation

1. Stick barrier at LCD Panel.

2. Stick Heat Rubber at Barrier.

3. Screw inverter board at LCD panel.

4. Slot mini LVDS wire at LCD panel board and inverter board.

5. Put LCD panel on the cabinet.

18

7.7. LED Panel Installation

1. Fix LED PANEL on CABINET.

2. Wire connecting. (V10).

3. Put V-PCB on CABINET.

4. Fix them with SCREW.

5. Insert the CLAMPER.

6. Stick felt at A10-V10 wire.

TC-L42S20BL

19

TC-L42S20BL

7.8. Felt Sticking at LVDS Wire

1. Insert CN1~P4 wire to inverter.

2. Insert CN201~P3 wire to inverter and stick felt.

3. Stick felt at LCD panel (Bottom left side).

4. Fix Top mtg and Bottom Mtg.

5. Fix Chassis frame bracket at Top Mtg and Bottom Mtg.

6. Insert LVDS wire to inverter and stick 3 felt.

7. Stick left at chassis frame to avoid sharp edge.

20

7.9. LCD Bracket and MTG Installation

1. Fix MASK BRACKET (SIDE/TOP/BTM) on the cabinet.

2. Fix Vertical Metal Bracket, Metal Support Bracket (R).

3. Fix them with SCREW.

4. Fix Clamper at Vertical Metal Bracket.

TC-L42S20BL

21

TC-L42S20BL

7.10. Pedestal Assembly

1. Fix stand mtg spacer at pedestal cover.

2. Stick felt at front base plate.

3. Fix base plate at stand mtg and pedestal cover and screw.

4. Stick rubber foot at rotation plate.

5. Apply grease at rotation plate and bush (pede).

6. Fix rotation plate and bush (pede) at base plate and screw.

22

Put Pedestal Assembly into polybag and fold properly.

TC-L42S20BL

23

TC-L42S20BL

8 Measurements and Adjustments

8.1. Voltage chart of A-board

Set IP-Board to a dummy set and check the satisfaction with the specified voltage as following table.

Power Supply Name Measurement Point Specification (V)

SUB1.8V TP5601 1.74 - 1.90

SUB1.2V TP5600 1.18 - 1.32

SUB3.3V TP5602 3.19 - 3.46

SUB5V TP5200 4.9 - 5.1

SUB9V TP5220 8.82 - 9.18

STB5V TP5400 4.9 - 5.1

8.2. Voltage chart of P-board

Set IP-Board to a dummy set or dummy load and check the satisfaction with the specified voltage as following table.

Power Supply

Name

P24V TP7503 24 ± 1.2 V NO CARE

17V TP7502 18 ± 2 V NO CARE

DTV12V TP7501 12 ± 0.6 V NO CARE

TUNER6V TP7601 6.1 ± 0.3 V NO CARE

DC390V TP7201 390 ± 10 V NO CARE * HOT

Measurement

Point

Normal Condition

(V)

Stby Condition

(V)

24

9 Block Diagram

A-BOARD

9.1. Main Block Diagram

V-BOARD

POWER LED

USB

SLOT

SD CARD

USB DATA

SD CARD DATA

DTV12V

SUB5V

STB5V

ANALOG-ASIC

OVP_DET

POWER LED

STB+3.3V

REMOTE RECEIVER

C.A.T.S. SENSOR

V10

A10

STB+3.3V

SOS DET

C.A.T.S. SENSOR

REMOTE RECEIVER

SOUND17V

DROP

VOLTAGE

D/A

ERROR DET

OVER

VOLTAGE

VREF_1-12

LVDS DATA

VCON31V

VOFF2-6V

DVDD2.5V

AVDD13.7V

TC-L42S20BL

LCD PANEL

A14

PANEL

CONTROL

PANEL

BACK LIGHT

(D Chip)

(A Chip)

TS Parallel

OFDM

IFD_OUT

V

SIF_OUT

DIGITAL SIGNAL PROCESSOR

TUNER

EEPROM

SIF

SD CARD DATA

TS Parallel

SOUND SOS

SOUND SOS

(LED:9TIMES)

(LED:9TIMES)

HDMI I/F

TMDS DATA

TMDS DATA

HDMI1

Peaks sLD

RECEIVER

TMDS DATA

HDMI3

HDMI2

(SIDE)

STB+5.8V

POWER SW

OVP_DET

SUB9V

DCDC

DTV12V

DTV12V

12V

SUB9V

STB5.8V

RELAY

DCDC

SUB3.3V

SUB3.3V

SUB_ON

DCDC

SUB1.8V

SUB1.8V

+5.8VS

A09

P2

SUB1.2V

DCDC

TUNER6V

SUB1.2V

SUB

DVDD2.5V

AVDD13.7V

(LED:3TIMES)

(LED:3TIMES)

DCDC

PANEL POWER SOS

AVDD13.7V

DVDD2.5V

SOUND17V

A02

K01

+5.8VS

ON

32V

17V

STB5V

DCDC

ON/OFF

STB5V

INV_PWM

INVERTER

TUNER5V

DCDC

INV_ON

POWER

+5.8VS

TUNER5V

INV_SOS

CONTROL

CURCUIT

DCDC

SUB5V

SUB5V

P5,P6.P7,P8

STB3.3V

STB3.3V

(STM)

STB_RESET

STB_RESET

A/D

L/R

EEPROM

AUDIO

PROCESSOR

D/A

CONVERTOR

DTV_L/R

CONVERTOR

Y/PB/PR,

R/G/B/H/V CVBS

REMOTE IN

POWER LED(R)

C.A.T.S. SENSOR

VIDEO

PROCESSOR

DVB_CVBS

SUB 3.3V SENSE

(LED:7TIMES)

(LED:7TIMES)

(LED:3TIMES)

(LED:3TIMES)

DTV12V SENSE

(LED:4TIMES)

(LED:4TIMES)

(LED:1TIMES)

(LED:1TIMES)

CPU BUS

I/F

NAND

FLASH

CPU BUS

PWM

HP

PANEL POWER SOS

INV_SOS

INV_ON

SUB_ON

KEYSCAN

INV_PWM

(DAC_ENB)
HOT START

INV_SOS

INV_ON

INV_PWM

LVDS DATA

OPERATION

BUTTON

AV SW

CONTROL PANEL

V

MONITOR L,R

V/Y/PB/PR

L/R

V

AV1

MONITOR V

L/R

L/R

V

R/G/B/H/V

PC

AV2

AV3

MONITOR

OUT

(SIDE)

PWM

L

HEADPHONE

(SIDE)

SPEAKER(L)

AUDIO

A12

SOS DET

AMP

R

SPEAKER(R)

K-BOARD

P-BOARD

POWER SUPPLY

RECTIFIER

PROCESS

VOLTAGE

RECTIFIER

POWER

CONTROL

PFC

CONTROL

STANDBY

VOLTAGE

RECTIFIER

RECTIFIER

AC CORD

NEUTRAL

P1

LINE

FILTER

LIVE

25

TC-L42S20BL

10 Wiring Connection Diagram

1. Fix PCB at chassis frame and mtg and screw.

2. Wiring No.1~No.6.

3. Remove dust of terminal of LVDS and PB connector. (by ion blow)

Wire

No.1 A10 - V10

No.2 A04 - K01

No.3 A11 - SP (R)

No.4 A11 - SP (L)

No.5 INV (CN 201) ~ P3

No.6 A3 ~ P2

Clamper

1 2 3 A B 6 7 8 C D 12 13

26

11 Schematic Diagram

11.1. Schematic Diagram Notes

TC-L42S20BL

27

TC-L42S20BL

11.2. A Board

11.2.1. A Board - Sheet : 002 (1 / 3)

<1A>

28

<2A>

11.2.2. A Board - Sheet : 002 (2 / 3)

<1A>

TC-L42S20BL

<2A>

<1B>

<2B>

<3B>

29

TC-L42S20BL

11.2.3. A Board - Sheet : 002 (3 / 3)

<1B>

<2B>

<3B>

30