Panasonic TC-19LX50, TC-23LX50, TC-19LE50, TC-23LE50 Service manual

Specifications

A

A

A

Y

A

Y

V

A

A

PowerSource

PowerConsumption

LCD 1280 × 768 pixels widescreen LCD panel (TC-19LX50, TC-19LE50)

Screen Size 16.3 “ × 9.8 “ ×18.9 “ (413 mm × 248 mm × 481 mm) (TC-19LX50, TC-19LE50)

(W × H × diagonal) 20.0 “ × 11.3 “ ×23.0 “ (508 mm × 286 mm × 583 mm) (TC-23LX50, TC-23LE50)

Channel Capability VHF-12 : UHF-56 : Cable-125

Sound

Speakers Ø5 cm × 2 pcs, 8 W (TC-19LX50, TC-19LE50)

Audio Output 8 W [4 W + 4 W] (10%THD)

Headphones M3 (3.5 mm) Jack × 1

FEATURES 3D Y/C Digital Comb Filter, CLOSED CAPTION, V-Chip

Operating Conditions Temperature : 41 °F - 95 °F (5 °C - 35 °C)

Connection Terminals

INPUT VIDEO (RCA PIN Type ×1) ×2 1.0 Vp-p (75 W)

COMPONENT

IDEO INPUT (including synchronization)

OUTPUT

LCD Television

TC-19LX50
TC-23LX50
TC-19LE50
TC-23LE50

LH44 Chassis

C 120 V, 60 Hz

verage use : 66 W (TC-19LX50, TC-19LE50)

verage use : 83 W (TC-23LX50, TC-23LE50)

Stand-bycondition : 0.11 W

Power off : 0.1 W

1366 × 768 pixels widescreen LCD panel (TC-23LX50, TC-23LE50)

Ø6 cm × 2 pcs, 8 W (TC-23LX50, TC-23LE50)

Humidity: 5 % - 90 % RH (non-condensing)

S-VIDEO (MINI DIN 4pin ×1) ×2

UDIO L-R (RCA PIN Type ×2) ×2 0.5 Vrms

×1 1.0 Vp-p

PB/PR×1 ±0.35 Vp-p

UDIO L-R (RCA PIN Type ×2) ×1 0.5 Vrms

UDIO L-R (RCA PIN Type ×2) ×1 0.5 Vrms

: 1.0 Vp-p (75 W ),

C : 0.286 Vp-p (75 W)

ORDER NO. ITD0503010CE

B05 Canada:B07

© 2005 Matsushita Electric Industrial Co., Ltd. All
rights reserved. Unauthorized copying and
distribution is a violation of law.

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

Dimensions ( W × H × D )

Including TV Stand 20.2 “ × 18.1 “ × 10.2 “ (514 mm × 459 mm × 259 mm) (TC-19LX50, TC-19LE50)

24.1 “ × 19.9 “ ×10.2 “ (612 mm × 505 mm × 259 mm) (TC-23LX50, TC-23LE50)

TV Set Only 20.2 “ × 15.6 “ ×4.9 “ (514 mm × 395 mm × 125 mm) (TC-19LX50, TC-19LE50)

24.1 “× 17.4 “ ×4.9 “ (612 mm × 441 mm × 125 mm) (TC-23LX50, TC-23LE50)

Mass (Weight) 8.5 kg (18.7 lb.) NET (TC-19LX50, TC-19LE50)

9.5 kg (20.9 lb.) NET (TC-23LX50, TC-23LE50)

Note:

Design and Specifications are subject to change without notice. Weight and Dimensions shown are approximate.

CONTENTS

Page Page

1 Safety Precautions 3

1.1. General Guidelines

2 Warning

2.1. Prevention of Electro Static Discharge (ESD) to

Electrostatically Sensitive (ES) Devices

2.2. About lead free solder (PbF)

3 Location of Controls and Components

4 Service Mode

4.1. How to enter into adjustment mode

4.2. Cancellation

4.3. Contents of adjustment mode

5 Troubleshooting Guide

5.1. Self-check function

6 Disassembly and Assembly Instructions

6.1. Removing the hinge cover

6.2. Removing the pedestal

6.3. Removing the back cover (TC-23LX50/LE50)

6.4. Removing the back cover (TC-19LX50/LE50)

6.5. Removing the tuner cover

6.6. Removing the shield cover

6.7. Removing the button panel and K-board

6.8. Removing the chassis

6.9. Removing the A-Board, AP-Board and Power Unit

6.10. Removing the speaker, and V-Board

6.11. Removing the LCD mount metal

6.12. Removing the LCD panel (TC-23LX50/LE50)

6.13. Removing the LCD panel (TC-19LX50/LE50)

6.14. Removing the LCD fixing metal

6.15. Location of Lead Wiring

7 Measurements and Adjustments

3

3

3

4

5

6

6

6

6

7

7

8

8

8

8

8

8

9

9

9

9

10

10

10

11

11

12

7.1. Video Signal Level Adjustment (RF)

8 Block Diagram

8.1. Block Diagram (1 of 3)

8.2. Block Diagram (2 of 3)

8.3. Block Diagram (3 of 3)

9 Wiring Connection Diagram

10 Schematic Diagrams

10.1. Schematic Diagram Notes

10.2. A-Board (1 of 6) Schematic Diagram

10.3. A-Board (2 of 6) Schematic Diagram

10.4. A-Board (3 of 6) Schematic Diagram

10.5. A-Board (4 of 6) Schematic Diagram

10.6. A-Board (5 of 6) Schematic Diagram

10.7. A-Board (6 of 6) Schematic Diagram

10.8. AP-Board Schematic Diagram

10.9. K-Board and V-Board Schematic Diagram

11 Printed Circuit Views

11.1. A-Board

11.2. AP-Board

11.3. K-Board and V-Board

12 Exploded View and Replacement Parts List

12.1. Parts Layout

12.2. Packing Exploded Views

12.3. Mechanical Replacement Parts List

13 Electrical Parts List

13.1. Electrical Parts List Notes

13.2. Electrical Replacement Parts List

13

13

15

15

16

17

19

21

21

22

23

24

25

26

27

28

29

31

31

34

35

37

37

38

39

40

40

41

2

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

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.

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 between
1MW and 5.2MW.

When the exposed metal does not have a return path to the
chassis, the reading must be

Figure 1

.

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 1.5kW, 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.

2 Warning

2.1. Prevention of Electro Static 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 electro static 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 alminum

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, alminum 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.

3

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

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 hamless 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).

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

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.

stamped on the back of PCB.

4

3 Location of Controls and Components

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

Board Name Function
A-Board Main (AV Switch, Audio, MCU, Grobal Core, AV connector )
V-Board Remote Reciever
K-Board Power switch, Control swtich
AP-Board DC-DC
Power Unit Power (AC/DC),

None serviceable.
Power Unit should be exchange for service.

5

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

4 Service Mode

4.1. How to enter into adjustment mode

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

4.1.1. Adjustment method.....Use the remote control.

“1” button...Main items Selection in forward direction

“2” button...Main items Selection in reverse direction

“3” button...Sub items Selection in forward direction

“4” button...Sub items Selection in reverse direction

“VOL” button...Value of sub items change in forward direction (

), in reverse direction ( )

4.2. Cancellation

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

4.3. 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 Remarks

MAIN YGAIN Video Level (RF, VIDEO, S, COMPONENT)

B-Y Video Level (RF, VIDEO, S, COMPONENT)
R-Y Video Level (RF, VIDEO, S, COMPONENT)
PILEN PILEN Current

SUB COLOR Sub color

TINT Sub tint
BACK-L Sub back light
BRIGHT Sub bright
B-Y-G B-Y Gain
R-Y-A R-Y demodulation axis
TEMP Temp data

GAMMA WHITE Test pattern (100% White)

RED Test pattern (100% Red)
GREEN Test pattern (100% Green)
BLUE Test pattern (100% Blue)
GRAY Test pattern (50% White)
R-GAIN Test pattern (100% White) R-GAIN
G-GAIN Test pattern (100% White) G-GAIN
B-GAIN Test pattern (100% White) B-GAIN
R-CENT Test pattern (50% White ) R-CENT
G-CENT Test pattern (50% White) G-CENT

B-CENT Test pattern (50% White) B-CENT
OPT OPT00 (TV)
RM CODE Remote control code A or B
MTS MTSIN RF Audio input

SEPAH Stereo separation Hi

SEPAL Stereo separation Low

6

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

5 Troubleshooting Guide

5.1. Self-check function

When phenomena like "the power fails from time to time" or "the video/audio fails from time to time" can not be confirmed at the
time of servicing, the self-check function can be used to confirm the occurrence and to limit the scope for the defective circuits.Also,
when "the power fails from time to time", display on the screen can be used to confirm the occurrence and to limit the scope for
the defective circuits.

Any programmed channels, channels caption data and some other user defined settings will be erased and return to factory setting.

5.1.1. How to access

5.1.1.1. Access

Produce TV reception screen and, while pressing [VOLUME-] button on the main unit, press [SLEEP] button on the remote
controller unit simultaneously.

5.1.1.2. Exit

When one of the buttons for channel selection etc. is pressed, the display returns to the normal screen.

5.1.2. Screen display

Display Ref No. Description P.C.B
UV TU001A Tuner A-Board
SND IC2301 Sound Control A-Board
AVSW IC3007 AV Switch A-Board
GC3FM IC4023 Global Core Main A-Board
GC4U IC4016 Global Core A-Board
MEM IC1104 EEPROM A-Board

7

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

6 Disassembly and Assembly Instructions

6.1. Removing the hinge cover

1. Lay down the unit so that the rear cover faces upward.

2. Remove the screw.

3. Remove the hinge cover.

6.2. Removing the pedestal

1. Remove the 4 screws.

2. Remove the pedestal.

6.4. Removing the back cover (TC­19LX50/LE50)

1. Remove the 14 screws.

2. Remove the back cover.

6.5. Removing the tuner cover

6.3. Removing the back cover (TC­23LX50/LE50)

1. Remove the 15 screws.

2. Remove the 2 screws.

3. Remove the back cover.

1. Remove the 2 screws.

2. Remove the tuner cover.

8

6.6. Removing the shield cover

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

6.8. Removing the chassis

1. Remove the 5 screws.

2. Remove the shield cover.

6.7. Removing the button panel
and K-board

1. Remove the 2 screws.

2. Remove the 2 screws.

3. Remove the button panel.

1. Remove the 5 screws.

2. Disconnect the coupler (A2, A5, AP5 and AP6).

3. Remove the chassis.

6.9. Removing the A-Board, AP­Board and Power Unit

1. Remove the 10 screws.

2. Disconnect the coupler (A3-AP3, A4-AP4 and AP1-CN1).

3. Remove A-Board, AP-Board and Power Unit.

4. Disconnect the coupler (K5).

5. Remove the K-Board.

9

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

6.10. Removing the speaker, and V­Board

6.11. Removing the LCD mount
metal

1. Remove the 8 screws.

2. Remove the speaker.

3. Remove the 2screw.

4. Disconnect the coupler (V1 and V2).

5. Remove the V-Board.

1. Remove the 5 screws.

2. Remove the LCD mount metal (bottom).

3. Remove the screw.

4. Remove the LCD mount metal (top).

6.12. Removing the LCD panel (TC­23LX50/LE50)

1. Remove the 2 screws.

2. Remove the LCD panel.

10

6.13. Removing the LCD panel (TC­19LX50/LE50)

1. Remove the 14 screws.

2. Remove the LCD panel.

6.14. Removing the LCD fixing
metal

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

1. Remove the 4 screws.

2. Remove the LCD fixing metal (L/R)

11

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

6.15. Location of Lead Wiring

12

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

7 Measurements and Adjustments

7.1. Video Signal Level Adjustment (RF)

Instrument Name Connect to Remarks

1. Remote controller

2. RF signal

3. SG

1. Receive studio color bar by RF signal input.

(Viewing mode: standard, LCD AI: OFF, Back Light: +30 )

2. In service mode choose adjust item then press remote button 1 into main mode then press remote 3 into Y Gain and press

remote button “8” to do auto adjustment.

3. Press remote button “2” go back main menu.

RF in

13

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

14

8 Block Diagram

8.1. Block Diagram (1 of 3)

TC-19LX50 / TC-23LX50 / TC-19LE50 / TC-23LE50

K-BOARD

SW3805

R3818

R3821

SW3804

VOLVOL

K5

2

KEYSCAN

3

RELAY

4

STB+5V

5

MAIN_SW_DET

6

+5VS

R3816

SW3808

R3817

SW3806

CH

PUSH

R3815

SW3803

A

TV/VTR

SW3807

CH

POWER SWITCH

AP-BOARD

AP6

2
3
4

MAIN_SW_DET

5
6

MAIN+9V

Q861

Q862

2

2

7.5V(PANEL_5V OVP)

DC-DC ON/OFF

D869

D873

11V(SUB_9V OVP)

D872

D876

D882

D884

D890

D889

R913

L:NORMAL
H:ABNORMAL

Q865

+30V(BT)/+5V(P)
SHORT DET

Q864

SOS DET

IC851

SUB+9V

1

AVR

KEY

IC854

PANEL+5V

AVR

1

5

Q856

PANEL 5V ON/OFF

Q857

R910

B

D879

R891

R896

R900

Q859

R892

D887

POWER UNIT

C13
2200p

15

13

12

D9

COLD

RC3

RC2

PC2

FEED BACK

POWER ON/OFF

+32V

+

C23

220u

+24V

+++

+

C17
100u

R14
1K

R14
150

Q2

C19

C18

100u

100u

+32V

RELAY

+5VS

AP1

19

1
2
3

4
14
13
11

CN2

1

19

+24V(INV)

18

D23

D21

R19
1K

R18

2.2K

+24V(INV)

17

+24V(INV)

16

+24V(INV)
6
7

POWER_ON

9

IC855

RC1

R3

0.1

D14

D11

D13

D12

RECTIFIER

1

2

SWITCHING REG

+

C6

330u

R9

DRIVE

CONTROL

Z2

4

3

D7

D6

22K

4

OSC

5

3

D10

D8

DD1

STBY 5V

GENE

COLD

C

D

AC CORD

2
1

CN1

HOT

COLD

SWITCHING TRANS

D17

6

5

HOT

T2

7
6

D24

4

D5

1

2

D18

C12
47u

RL1

5V

+

C21

1000u

HOT

Q869

R932

R930

R931

Q868

D886

SOUND+10V

AVR

1

5

Q854

DC-DC ON/OFF

IC853

SUB+5V

1

2

AVR

R933

2

BT_30V

R935

Q870

R934

13V(SOUND_10V OVP)

MAIN+3.3V

1

D871

R936

R937

D877

D878

IC852

AVR

5

Q855

DC-DC ON/OFF

D875

7.5V(SUB_5V OVP)

2

DC-DC ON/OFF CONTROL

Q866

TO
LCD PANEL
(INVERTER)

Q867

AP3

4
5

9
13
15
18
20
22

AP4

1

3

MAIN_SW_DET

KEY

INV_SOS

INV_ADIM
INV_PWM
INV_ON

INV_ON

INV_PWM

INV_SOS

INV_ADIM

1417131812

2

+24V(INV)

4

+24V(INV)

5143

+24V(INV)

+24V(INV)

11

INV_SOS

INV_ON

INV_ADIM

INV_PWM

1

AP4

+24V(INV)

6

7

8
10
11
13
14
15
16

E

TC-19/23LX50, TC-19/23LE50
Block Diagram (1/3)

TC-19/23LX50, TC-19/23LE50 Block Diagram (1/3)

2

746

81 53

15