Panasonic TC-23LX60 Service manual

TC-23LX60

LH58

MTNC060587CE

B05

LCD TV

CONTENTS

Page Page

1 Safety precautions 3

2 Warning

2.1. Prevention of Electro Static Discharge (ESD) to

Electrostatically Sensitive (ES) Devices

3 About lead free solder (PbF)

4 Receiver feature table

5 Chassis Board Layout

6 Location of controls (EUR7613Z90R)

7 Service Mode

7.1. How to enter into adjustment mode

7.2. Adjustment method.....Use the remote control.

7.3. Cancellation

7.4. Contents of adjustment mode

8 Troubleshooting Guide

8.1. Self-check function

8.2. How to access

8.3. Screen Display

9 Disassembly Instructions 8

9.1. Removing the Chassis fromLC D panel and cabinet

9.2. Removing the LCD L/R/B MTG from the LCD panel

9.3. Removing the LCD panel from Cabinet

10 Measurements and Adjustments

10.1. White Balance Adjustment

11 MTS circuit adjustment

12 Boards Assemblies

12.1. AP-Board

12.2. A-Board

12.3. P-Board

12.4. K-Board

12.5. V-Board

13 Block Diagram

13.1. Block Diagram for P and AP (DC-DC CONV.) (1 of 2)

13.2. Block Diagram for P and AP (DC-DC CONV.) (2 of 2)

14 Schematic Diagrams

14.1. Schematic Diagram Notes 22

14.2. Reference of PDF links color

14.3. A-Board (1 of 8) Schematic Diagram

14.4. A-Board (2 of 8) Schematic Diagram

14.5. A-Board (3 of 8) Schematic Diagram

14.6. A-Board (4 of 8) Schematic Diagram

14.7. A-Board (5 of 8) Schematic Diagram

14.8. A-Board (6 of 8) Schematic Diagram

14.9. A-Board (7 of 8) Schematic Diagram

14.10. A-Board (8 of 8) Schematic Diagram

14.11. AP-Board (1 of 2) Schematic Diagram

14.12. AP-Board (2 of 2) Schematic Diagram

14.13. V-Board Schem atic Diagram

14.14. K-Board Schem atic Diagram

15 Printed Circuit Boards

15.1. A-Board Top Side

15.2. A-Board Bottom Side

15.3. AP-Board (top)

15.4. AP-Board (bottom)

15.5. V Board

15.6. K Board

16 Parts Location

16.1. Packing Exploded View

17 Parts list

17.1. Description of abbreviations guide

17.2. Parts list

1 Safety precautions

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.

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 1MΩ and 5.2MΩ. When

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

Figure 1. Hot check circuit

Leakage current hot check

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

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

0.15F 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 0.5 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 fieldeffect 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.

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).

3 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 manufacturin g 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” or 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.

stamped on the back of PCB.

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.

4 Receiver feature table

FEATURE / MODEL TC-23LX60 LCD TYPE IPS (WXG A) LCD PANEL MAKER LG CHASSIS LH58 SYSTEM NTSC TUNING FST STEREO MTS/SAP CATV USA CATV 181CH POWER SUPPLY AC120-127V, 60HZ AV-IN 2 (RCA) S-VHS-IN 2 COMPONENT VIDEO-IN VIDEO 1 / AUDIO 1 (RCA) AV-OUT 1 (RCA) HDMI 1 DVI NONE PC-INPUT NONE HEAD PHONE X PEAKS SYSTEM ----GC SYSTEM MICRONAS VCTP PROGRESSIVE X 3D Y/CCOMB FILTER X SUB PIXCEL CONTROLER NONE GRS NONE AUDIO OUTPUT 4W + 4W SPEAKER SYSTEM UNDER/1 WAY - SPEAKER BASS/TREBLE X BALANCE X DTS NONE SURROUND X AUDIO OUT PERFORMANCE FAO SAFETY-STANDARD UL STANDARD-ORGANIZATION E-STAR EMC (EMISSION) BETS-7 MECHANICAL ISTA JPEG NONE MPEG4 NONE MPEG2 NONE ASPECT X CHANNEL BANNER NONE VIDEO PICTURE MEMORY NONE MULTI WINDOW NONE BLUE BACK (AV) NONE GAME MODE NONE GAME GUARD NONE OFF TIMER X AUTO SEARCH X DEMOSTRATION MODE ----CLOSED CAPTION X V-CHIP X VESA COMPATIBLE OSD LANGUAGE ENGLISH (US) / FRENCH / SPANISH REMOTE CONTROLLER EUR7613Z90R CEC OF HDMI CONNECTION DIGA PEDESTAL SWIVEL AND TILT SD SLOT FOR DL NONE

Note:

Specifications are subject to change without notice or obligation.

5 Chassis Board Layout

Board Layout

Board Name TC-23LX60 Function A-Board TZRXN010MRJE Main (AV Switch, Audio, MCU, AV connector) AP-Board TZRXN020MRJE DC-DC K-Board TZRXN030MRJE Headphone Jack V-Board TNPA3749ACS Remote Reciever, LED POWER UNIT N0AB3GH00003 AC-DC

6 Location of controls (EUR7613Z90R)

7 Service Mode

7.1. How to enter into adjustment mode

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

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.

7.2. 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

7.3. Cancellation

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

7.4. 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

PCT-ADJ COLOR Sub color Adjustment

R-Y-A recovery axis (R-Y) B-Y-G Gain (B-Y) BACK-L Sub-backlight TINT Tint Adjustment

WB-ADJ (White balance adjustment)

OPTION OPTOO TV (for TV) (Not ADJ)

MTS-ADJ MTSIN RF Audio input level detection

B-CENT Blue Gain by test pattern (50% white) G-CENT Green Gain by test pattern (50% white) R-CENT Red Gain by test pattern (50% white) B-GAIN Blue Gain by test pattern (100% white) G-GAIN Green Gain by test pattern (100% white) R-GAIN Red Gain by test pattern (100% white)

CEC-CHK For service only EEP-COPY For service only

SEPAH Stereo separation Hi SEPAL Stereo separation low

8.2. How to access

Access

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

Exit

Press the POWER button twice (off/on) to return to the normal screen.

8.3. Screen Display

9 Disassembly Instructions

Back cover removal (screw location)

8 Troubleshooting Guide

8.1. 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

1. Remove all the screw from the back cover and pedestal as indicated with arrows.

Without the back cover

1. First remove the five screws located around the bracket.

P-Board (POWER UNIT) Disassembly

by arrows.

A-Board Disassembly

1. To remove the A-Board bracket shown above remove the screws indicated on the figure above by arrows.

K-Board Disassembly

1. To remove the P-Board remove the screws indicated on the figure above by arrows.

AP-Board Disassembly

1. To remove the AP-Board first lift the four connectors then remove the screws indicated on the figure above

1. To remove the K-Board shown above release the tab indicated on the figure by arrow.

Speaker Disassembly

1. To remove the speaker remove the screws indicated on the figure by arrows, each speaker is located on sides.

V-Board Disassembly

1. To remove the V-Board remove the screws indicated on the figure by arrows.

Removing the pedestal with back cover

1. Lay down the unit with back cover in place so that the rear cover faces upward.

2. Refer to back cover removal diagram on previous page to remove back cover and pedestal.

3. Add the 4 screws back to the pedestal as shown in diagram above without back cover, if needed.

Note: Remember the 4 screws in the pedestal are also screwed into the back cover.

9.1. Removing the Chassis fromLCD panel and cabinet

1. Remove the 8 screws.

2. Remove the chassis from the LCD panel assy and cabinet.

9.2. Removing the LCD L/R/B MTG from the LCD panel

1. Remove the 7 screws.

2. Remove the chassis from LCD and cabinet assy.

9.3. Removing the LCD panel from Cabinet

1. Remove the LCD panel from cabinet.

10 Measurements and Adjustments

10.1. White Balance Adjustment

11 MTS circuit adjustment

The MTS circuit adjustment require two steps:

1. Input level adjustment.

2. Stereo separation adjustment.

Input level adjustment Service DAC adjustment (MTSIN)

PREPARATION

1. Connect an RMS meter with filter jig as shown in figure to TP1105 or TP1107 and gound.

2. Connect an RF sigal generator to the RF antenna Input.

PROCEDURE

1. Apply the following signal from the RF signal generator.

• Video: flat field, 30% modulation (70±5dB, 75 ohm

OPEN, P/S 10dB).

• Audio: 300Hz, 100% modulation, monaural

(70±5dB, 75 ohm OPEN, P/S 10dB.) Make sure that the 75µs pre-emphasis is OFF.

2. Adjust the MTS input level adjustment “MTSIN” data until the RMS voltage measured is 106mVrms ±

6.0mVrms.

Stereo separation adjustment (SEPAH)

PREPARATION

1. Connect an R.F. signal generator to the RF antenna input.

2. Connect a scope to TP1104 or TP1106 and ground.

PROCEDURE

1. Select stereo mode in audio menu.

2. Apply the following signal from the RF signal generator.

• Video: flat field, 30% modulation.

• Audio: 300Hz, 30% modulation, stereo (left only)

(70±5dB, 75 ohm OPEN, P/S 10dB.)

Note: After setting 30% modulation with P.L. SW and N.R. SW OFF, turn P.L. SW and N.R. SW ON.

3. In service mode, adjust the MTS Low-Level separation adjustment “SEPAL” data until the amplitude displayed on the scope is minimum.

4. Apply the following signal from the RF signal generator.