Panasonic TC-26LX70, TC-32LX70 Service manual

26”/32” DIAGONAL LCD TV

LH65A Chassis

Specifications

PowerSource PowerConsumption

Average use 116 W (TC-26LX70)

Maximum Current 2.1 A (TC-26LX70)

Standby condition 0.1 W Aspect Ratio 16 : 9

isible screen size

(W × H × Diagonal)

(No. ofpixels) 1,049,088 (1,366 (W) × 768(H)) [4,098 × 768 dots]

Sound

Speake Audio Output 20 W (10 W × 2) ( 10 % THD ) Headphones M3 (3.5mm) Jack × 1

Channel Capability - VHF/UHF: 2 - 69, CATV: 1 - 135 ATSC/NTSC(Digital/Analog) Operating Conditions Temperature: 32 °F - 95 °F (0 °C - 35 °C)

Connection Terminals

INPUT 1-2 VIDEO: RCA PIN Type × 1 1.0 V [p-p] (75 ohm)

INPUT 3 VIDEO: RCA PIN Type × 1 1.0 V [p-p] (75 ohm)

C 120-127 V, 60 Hz

132 W (TC-32LX70)

2.3 A (TC-32LX70)

26.0 " DIAGONAL (66.1 cm DIAGONAL) (TC-26LX70)

31.5 " DIAGONAL (80.0 cm DIAGONAL) (TC-32LX70)

22.7 " × 12.8 " × 26.0 " (576 mm × 324 mm × 661 mm) (TC-26LX70)

27.5 " × 15.4 " × 31.5 " (698 mm × 392 mm × 800 mm) (TC-32LX70)

1way2 speakers

Humidity: 20 % - 80 % RH (non-condensing)

S-VIDEO: Mini DIN 4-pin Y: 1.0 V [p-p] (75 ohm) C: 0.286 V [p-p] (75 ohm)

UDIO L-R: RCA PIN Type × 2 0.5 V [rms]

ORDER NO.MTNC070304CE

B05 Canada: B07

TC-26LX70 / TC-32LX70

COMPONENT VIDEO INPUT

HDMI 1-2 TYPE A Connector×2 AUDIO IN This TV supports “HDAVI Control 2" function.

OUTPUT VIDEO: RCA PIN Type × 1 1.0 V [p-p] (75 ohm)

DIGITAL AUDIO OUT PCM/DolbyDigital, FiberOptic

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

Dimensions (W × H × D)

Including TV stand 25.9 " × 20.3 " × 9.4 " (657 mm × 515 mm × 239 mm) (TC-26LX70)

TV Set only 25.9 " × 18.4 " × 4.6 " (657 mm × 468 mm × 117 mm) (TC-26LX70)

Weight 31.1 lb. (14.0 kg ) NET (TC-26LX70)

Y: 1.0 V [p-p] (including synchronization) PB,PR: ± 0.35 V [p-p]

UDIO L-R: RCA PIN Type × 2 0.5 V [rms]

HDMI (HDAVI Control 2) Vesa compatible Photo Viewer

31.1 " × 23.3 " × 9.4 " (791 mm × 592 mm × 239 mm) (TC-32LX70)

31.1 " × 21.5 " × 4.6 " (791 mm × 545 mm × 117 mm) (TC-32LX70)

36.7 lb. (16.5 kg ) NET (TC-32LX70)

Note:

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

CONTENTS

Page Page

1 Applicable signals 4 2 Safety Precautions

2.1. General Guidelines

3 Prevention of Electro Static Discharge (ESD) to

Electrostatically Sensitive (ES) Devices 4 About lead free solder (PbF) 5 Chassis Board Layout 6 Disassembly for Service

6.1. Pedestal assy

6.2. Rear cover

6.3. VESA metal

6.4. AC cord

6.5. Tuner cover

6.6. Power button bracket

6.7. Control panel assy

6.8. G-Board

6.9. Side AV bracket and Inverter shield

6.10. AP-Board

6.11. P-Board

6.12. DT-Board

6.13. A-Board and DT-Board metal

6.14. Chassis

6.15. LCD MTG and LCD panel

6.16. Speaker

10 10 10 10 11 11 12 12 12 13 13 14 14

6 7 8 9

9 9 9

6.17. V-Board

7 Caution statement

7.1. Caution statement.

8 Location of Lead Wiring

8.1. Wire dressing (32 inch)

8.2. Wire dressing (26 inch)

9 EMI Processing

9.1. EMI (32 inch)

9.2. EMI (26 inch)

10 Self-c heck Function

10.1. Check of the IIC bus lines

10.2. Power LED Blinking timing chart

10.3. No Power

11 Service Mode

11.1. How to enter into Service Mode

11.2. SRV-TOOL

12 Adjustment

12.1. Voltage chart of AP-board

12.2. Voltage chart of P-board

12.3. Voltage chart of A-board

12.4. Picture level adjustment (RF)

13 Hotel mode 14 Conductor Views

14.1. AP-Board (32 inch)

17 18

19 21

23 24 25

26 27

28 28 28 28

29 31

14.2. AP-Board (26 inch) 33

14.3. A-Board

14.4. DT-Board

14.5. G and V-Board

15 Sche matic and Block Diagr am

15.1. Schematic Diagram Notes

15.2. Block Diagram (1 of 2)

15.3. Block Diagram (2 of 2)

15.4. Interconnection Schematic Diagram

15.5. AP-Board (1 of 2) Schematic Diagram (26 inch)

15.6. AP-Board (2 of 2) Schematic Diagram (26 inch)

15.7. AP-Board (1 of 2) Schematic Diagram (32 inch)

15.8. AP-Board (2 of 2) Schematic Diagram (32 inch)

15.9. A-Board (1 of 10) Schematic Diagram

15.10. A-Board (2 of 10) Schematic Diagram

15.11. A-Board (3 of 10) Schematic Diagram 35 38 39

41 42 43 44 45 46 47 48 49

15.12. A-Board (4 of 10) Schematic Diagram

15.13. A-Board (5 of 10) Schematic Diagram

15.14. A-Board (6 of 10) Schematic Diagram

15.15. A-Board (7 of 10) Schematic Diagram

15.16. A-Board (8 of 10) Schematic Diagram

15.17. A-Board (9 of 10) Schematic Diagram

15.18. A-Board (10 of 10) Schematic Diagram

15.19. DT, G and V-Board Schematic Diagram

16 Explo ded View and Replacement Parts List

16.1. Exploded View

16.2. Replacement Parts List Notes

16.3. Mechanical Replacement Parts List

16.4. Electrical Replacement Parts List 50

TC-26LX70 / TC-32LX70

51 52 53 54 55 56 57 58 59

61 62 63 64

TC-26LX70 / TC-32LX70

1 Applicable signals

* Mark: Applicable input signal for Component (Y, PB,PR) and HDMI

horizontal frequency (kHz) vertical frequency (kHz) COMPONENT HDMI 525 (480) / 60i 15.73 59.94 * * 525 (480) /60p 31.47 59.94 * * 750 (720) /60p 45.00 59.94 * * 1,125 (1,080) /60i 33.75 59.94 * * 1,125 (1,080)/60p 67.43 59.94 * 1,125 (1,080)/60p 67.50 60.00 *

Note:

· Signals other than those shown above may not be displayed properly.

· ·

· The above signals are reformatted for optimal viewing on your display.

· ·

TC-26LX70 / TC-32LX70

2 Safety Precautions

2.1. 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.

2.1.1. 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

Figure 1

2.1.2. 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 ACplugintheACoutlet and repeat eachof 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.

TC-26LX70 / TC-32LX70

3 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 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).

TC-26LX70 / TC-32LX70

4 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.

TC-26LX70 / TC-32LX70

5 Chassis Board Layout

6 Disassembly for Service

6.1. Pedestal assy

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

2. Remove the 4 screws.

3. Remove the pedestal assy.

TC-26LX70 / TC-32LX70

6.2. Rear cover

1. Remove the 16 (32”) / 14 (26”) screws.

2. Remove the rear cover.

6.3. VESA metal

1. Remove the 4 screws.

2. Remove the VESA metal.

TC-26LX70 / TC-32LX70

6.4. AC cord

6.6. Power button bracket

1. Remove the bushing of the AC cord from the tuner cover.

2. Disconnect the connector (CN1) of AC cord.

6.5. Tuner cover

1. Remove the 2 screws.

2. Remove the tuner cover.

1. Remove the 2 screws.

2. Remove the power button bracket.

6.7. Control panel assy

1. Disconnect the connector (AP6).

2. Remove the 2 screws.

3. Remove the control panel assy.

6.8. G-Board

1. Remove the 2 screws.

2. Disconnect the connector (G4).

3. Remove the G-Board.

TC-26LX70 / TC-32LX70

6.9. Side AV bracket and Inverter shield

1. Remove the screw (A).

2. Remove the screw (B).

3. Remove the 2 screws (C).

4. Remove the side AV bracket and the inverter shield.

TC-26LX70 / TC-32LX70

6.10. AP-Board

1. Remove the 3 (32”) / 2 (26”) screws.

2. Disconnect the connectors (A3/A4/CN3).

3. Remove the AP-Board.

6.11. P-Board

1. Remove the 7 screws.

2. Disconnect the connectors (CN2/CN4).

3. Remove the P-Board.

6.12. DT-Board

1. Remove the 4 screws.

2. Remove the DT-Board.

6.13. A-Board and DT-Board metal

TC-26LX70 / TC-32LX70

6.14. Chassis

1. Remove the 10 screws.

2. Disconnect the connector (A2/A5/A8/A9/A16).

3. Remove the 2 screws.

4. Remove the A-Board and DT-Board metal.

1. Remove the 2 screws (D).

2. Remove the 2 screws (E).

3. Remove the 2 screws (F).

4. Remove the chassis.

TC-26LX70 / TC-32LX70

6.15. LCD MTG and LCD panel

1. Remove the 4 (32”) / 2 (26”) screws (G).

2. Remove the 7 (32”) / 6 (26”) screws (H)

3. Remove the LCD MTG.

6.16. Speaker

1. Remove the 2 screws.

2. Remove the speaker.

4. Remove the LCD panel.

6.17. V-Board

1. Remove the 2 screws.

2. Disconnect the connector (V1).

3. Remove the V-Board.

TC-26LX70 / TC-32LX70

7 Caution statement

7.1. Caution statement.

Caution:

Please confirm that all flexible cables are assembled correctly. Also make sure that they are locked in the connectors. Verify by giving the flexible cables a very slight pull.

8 Location of Lead Wiring

8.1. Wire dressing (32 inch)

TC-26LX70 / TC-32LX70

8.2. Wire dressing (26 inch)

9 EMI Processing

9.1. EMI (32 inch)

TC-26LX70 / TC-32LX70

9.2. EMI (26 inch)

TC-26LX70 / TC-32LX70

10 Self-check Function

Use the self-check function to test the unit.

1. Checking the IIC bus lines

2. Power LED Blinking timing

10.1. Check of the IIC bus lines

10.1.1. 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.

10.1.2. Exit

Disconnect the AC cord from wall outlet.

10.1.3. Screen display

10.1.4. Check Point

Confirm the following parts if NG was displayed.

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