Panasonic TC-17LA1, TC-20LA1 Service manual

TC-17LA1

A

V

TC-20LA1

LH14 Chassis

ORDER NO. ITD0304003C1

B05 Canada:B07

LCD TV

Specifications

Power Source AC 120V, 60Hz
Power Consumption Average use: 60W (TC-17LA1)

Stand-by condition: 0.8 W (TC-17LA1) Stand-by condition: 0.8 W (TC-20LA1)
TV set DC 15 V, 3.6 A max. (TC-17LA1) TV set DC 15 V, 3.8 A max. (TC-20LA1)

LCD 17-inch (432 mm) (TC-17LA1), 20-inch (510 mm) (TC-20LA1),

4 : 3 aspect ratio LCD panel 4 : 3 aspect ratio LCD panel

Screen Size 13.53" (343.7 mm) (W) × 10.30" (261.9 mm) (H)

(TC-17LA1)
Channel Capability VHF-12: UHF-56: Cable-125
Sound

Speaker 4 cm, 2pcs, 16 9
Headphones M3 (3.5 mm) Jack × 1

FEATURES 3D Y/C Digital Comb Filter

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

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

INPUT VIDEO (RCA PIN Type × 1) × 2 1.0 Vp-p (75 9)

S-VIDEO (MINI DIN 4 pin × 1) × 2 Y: 1 Vp-p (75 9), C: 0.286 Vp-p (75 9)

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

COMPONENT VIDEO INPUT Y 1.0 Vp-p (including synchronization)

PB/P

R

AUDIO L-R (RCA PIN Type × 2) 0.5Vrms
Dimensions (W x H x D)

Including TV Stand 16.69" (424 mm) × 16.35" (415.2 mm) × 8.46" (215

mm) (TC-17LA1)

verage use: 67W (TC-20LA1)

16.06" (408.0 mm) (W) × 12.05" (306.0 mm) (H)
(TC-20LA1)

-Chip

±0.35Vp-p

19.45" (494 mm) ×18.17" (461.4 mm) × 10.04" (255
mm) (TC-20LA1)

© 2003 Matsushita Electric Industrial Co., Ltd. All
rights reserved. Unauthorized copying and
distribution is a violation of law.

TC-17LA1 / TC-20LA1

TV Set Only 16.69" (424 mm) × 15.02" (381.5 mm) × 2.52" (64.1

mm) (TC-17LA1)

Mass (Weight) 11.46 lb. (5.2 kg) Net (TC-17LA1) 15.87 lb. (7.2 kg) Net (TC-20LA1)

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

19.45" (494 mm) × 16.63" (422.3 mm) × 3.21" (81.5
mm) (TC-20LA1)

CONTENTS

Page Page

1 Safety Precautions 3

1.1. General Guidelines

2 Prevention of Electro Static Discharge (ESD) to

Electrostatically Sensitive (ES) Devices
3 About lead free solder (PbF)
4 Self-check function

4.1. How to access

4.2. Screen display

4.3. Display phenomenon and treatment method

5 Chassis Board Layout
6 Before servicing

6.1. Kind and location of the flexible cable

6.2. How to remove the connector

7 Disassembly for Service

7.1. Rear cover

7.2. AP-BOARD

7.3. DG-Board

7.4. V-Board

7.5. Speaker (L, R)

7.6. B-Board

7.7. K-Board

7.8. BL-Board

7.9. LCD panel

8 Adjustment method

8.1. How to enter into adjustment mode

8.2. Cancellation

8.3. Contents of adjustment mode

8.4. Video level adjustment

10
11
13
13
14
14
15
16

19

19
19
19
20

3

3
4
5

5
5
5

6
7

7
8

9

9

8.5. Flicker Adjustment

8.6. MTS Adjustment

9 Conductor Views

9.1. AP-Board

9.2. DG-Board (TC-17LA1)

9.3. DG-Board (TC-20LA1)

9.4. B, BL, K and V-Board

10 Block and Schematic Diagram

10.1. Schematic Diagram Notes

10.2. Power Block Diagram

10.3. Signal Block Diagram

10.4. AP-Board (1 of 3) Schematic Diagram

10.5. AP-Board (2 of 3) Schematic Diagram

10.6. AP-Board (3 of 3) Schematic Diagram

10.7. DG-Board (1 of 3) (For TC-17LA1) Schematic Diagram

10.8. DG-Board (2 of 3) (For TC-17LA1) Schematic Diagram

10.9. DG-Board (3 of 3) (For TC-17LA1) Schematic Diagram

10.10. DG-Board (1 of 3) (For TC-20LA1) Schematic Diagram

10.11. DG-Board (2 of 3) (For TC-20LA1) Schematic Diagram

10.12. DG-Board (3 of 3) (For TC-20LA1) Schematic Diagram

10.13. B, BL, K, and V-Board Schematic Diagram

11 Parts Location & Mechanical Replacement Parts List

11.1. Parts Location

11.2. Packing Exploded View

11.3. Mechanical Replacement Parts List

12 Replacement Parts List

12.1. Replacement Parts List Notes

12.2. Electrical Replacement Parts List

23
24

25

25
27
28
29

31

31
32
34
36
37
38
39
40
41
42
43
44
45

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47
48
49

50

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2

TC-17LA1 / TC-20LA1

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
1M9 and 5.2M9.

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 1.5k9, 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 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-17LA1 / TC-20LA1

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 manufacturing process and discussed below is (Sn+Ag+Cu).
That is Tin (Sn), Silver (Ag) and (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

TC-17LA1 / TC-20LA1

4 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.

4.1. How to access

4.1.1. Access

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

4.1.2. Exit

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

4.2. Screen display

4.3. Display phenomenon and treatment method

Display symbol Phenomenon/condition Treatment method
H10 No output of video and audio. Replace tuner (TNR001A (B-BOARD)).
H21 No audio output. Surround function not effective. Replace IC2300 (AP-BOARD).
F30 No video and audio output. Input switching disabled. Replace IC3000 (AP-BOARD).
H34 Black and white stripes pattern. Enhanced back light. Replace IC4003 (DG-BOARD).
H35 No video Replace IC6400 (DG-BOARD).
H36 No video Replace IC6300 (DG-BOARD).
H90 Power interrupted with self-check. Replace IC1002 (DG-BOARD).

* Any button operation or switching off the power will reset the self-check data.

5

TC-17LA1 / TC-20LA1

5 Chassis Board Layout

Board Name Function
AP-Board Audio, Power, Inverter, AV SW
B-Board Tuner
BL-Board Inverter
DG-Board GC2, PCN, MICOM, EEPROM
K-Board Switch
V-Board Remote sensor, LED

6

6 Before servicing

6.1. Kind and location of the flexible cable

Ref No. Flexible cable Connector type Pins Location Opposite Ref No.

AP1 l type1 50 pin AP-BOARD DG1
AP2 - - 15 pin AP-BOARD B2
AP3 - - 9pin AP-BOARD B3
AP4 - - 2pin AP-BOARD Back Light (U)
AP6 - - 2 AP-BOARD Back Light (U)
AP8 - - 4pin AP-BOARD K8
AP9 l type2 12 pin AP-BOARD V9

AP10 - - 11 pin AP-BOARD BL1

B2 - - 15 pin B-BOARD AP2

B3 - - 9pin B-BOARD AP3
BL1 - - 11 pin BL-BOARD AP10
BL4 - - 2pin BL-BOARD Back Light (D)
BL6 - - 2pin BL-BOARD Back Light (D)
DG1 l type3 50 pin DG-BOARD AP10
DG3 l type3 50 pin DG-BOARD (TC-20LA1 only) P101
DG4 l type5 40 pin DG-BOARD (TC-17LA1 only) LCD Panel
DG5 l type5 40 pin DG-BOARD (TC-17LA1 only) LCD Panel

K8 - - 4pin K-BOARD AP8

P101 l type5 50 pin LCD Panel DG3

V2 - - 2pin V-BOARD Speaker (R)

V3 - - 2pin V-BOARD Speaker (L)

V9 l type4 12 pin V-BOARD AP9

TC-17LA1 / TC-20LA1

<TC-17LA1> <TC-20LA1>

7

TC-17LA1 / TC-20LA1

6.2. How to remove the connector

Connector type1

Connector type2

Connector type4

Connector type5

Connector type3

8

7 Disassembly for Service

7.1. Rear cover

1.Thick cloth and so on is down not to damage a LCD screen,
and the unit is pushed down.

TC-17LA1 / TC-20LA1

3.Remove the screws (9 pcs) (TC-20LA1) / (7 pcs) (TC­17LA1), the screws (2 pcs), and the screws (4 pcs), and
detach the rear cover and top cover.

2.Remove the screw (1 pcs), and detach the hinge cover and
the AV cable cover.

9

TC-17LA1 / TC-20LA1

7.2. AP-BOARD

1.Remove the rear cover.

2.Remove the screws (6 pcs) and the screws (2 pcs) (TC­20LA1) / (1 pcs) (TC-17LA1) and detach the shield plate
and Inverter plate (U, D).

3.Disengage the shaft holder hook and detach the power
button shaft.

4.<TC-20LA1 only>
Remove the screw (1 pcs) and the screws (4 pcs) and

detach the lock hinge plate.

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2­3kg·mm)

Do not tighten screws so hard.

10

5.Remove the screw (1 pcs) and disconnect the couplers (B2
(AP2) and B3 (AP3)) between B-Board and the AP-Board.

6.Disconnect the couplers (AP4, AP6, AP8 and AP10) the
flexible cable (AP1 and AP9) and remove the screws (3
pcs) and detach the AP-Board.

TC-17LA1 / TC-20LA1

7.3. DG-Board

1.Remove the rear cover.

2.Remove the screws (6 pcs) and the screws (2 pcs) (TC­20LA1) / (1 pcs) (TC-17LA1) and detach the shield plate
and Inverter plate (U, D).

11

TC-17LA1 / TC-20LA1

3.<TC-20LA1 only>
Remove the screw (1 pcs) and the screws (4 pcs) and

detach the lock hinge plate.

4.Disconnect the flexible cable (DG1 and DG3 (TC-20LA1)/
DG4, DG5 (TC-17LA1) ) and remove the screws (2 pcs) and
detach the DG-Board.

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2­3kg·mm)

Do not tighten screws so hard.

12

7.4. V-Board

TC-17LA1 / TC-20LA1

7.5. Speaker (L, R)

1.Remove the rear cover.

2.<TC-20LA1 only>
Remove the screw (1 pcs) and the screws (4 pcs) and

detach the lock hinge plate.

1.Remove the rear cover.

2.<TC-20LA1 only>
Remove the screw (1 pcs) and the screws (4 pcs) and

detach the lock hinge plate.

3.Remove the screw (1 pcs) and disconnect the couplers (V2
and V3) and the flexible cable (V9) and detach the V-Board.

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

3.Remove the screw (1 pcs) and the screws (6 pcs) and
disconnect the couplers (V2 and V3) and the Speakers (L,
R).

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

13

TC-17LA1 / TC-20LA1

7.6. B-Board

1.Remove the rear cover.

2.Remove the screw (1 pcs) and the screws (4 pcs) and
detach the lock hinge plate.

3.Remove the screw (1 pcs) and disconnect the couplers (B2
(AP2) and B3 (AP3)) between B-Board and the AP-Board.

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

7.7. K-Board

1.Remove the rear cover.

2.Remove the screws (6 pcs) and the screws (2 pcs) (TC­20LA1) / (1 pcs) (TC-17LA1) and detach the shield plate
and Inverter plate (U, D).

14

3.Disconnect the coupler (AP8) and disengage the hook (2
pcs) and detach the K-Board.

TC-17LA1 / TC-20LA1

7.8. BL-Board

1.Remove the rear cover.

2.Remove the screws (6 pcs) and the screws (2 pcs) (TC­20LA1) / (1 pcs) (TC-17LA1) and detach the shield plate
and Inverter plate (U, D).

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

15

TC-17LA1 / TC-20LA1

3.Disconnect the couplers (AP10, BL4 and BL6) and remove
the screws (2 pcs) and detach the BL-Board.

7.9. LCD panel

1.Remove the rear cover.

2.Remove the screws (6 pcs) and the screws (2 pcs) (TC­20LA1) / (1 pcs) (TC-17LA1) and detach the shield plate
and Inverter plate (U, D).

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

16

TC-17LA1 / TC-20LA1

3.Disengage the shaft holder hook and detach the power
button shaft.

5.<TC-20LA1 only>
Remove the screw (1 pcs) and the screws (4 pcs) and

detach the lock hinge plate.

4.Disconnect the coupler (AP8) and detach the circuit board
K bracket with K-Board.

6.Remove the screw (1 pcs) and disconnect the couplers (B2
(AP2) and B3 (AP3)) between B-Board and the AP-Board.

17

TC-17LA1 / TC-20LA1

7.Disconnect the couplers (AP4, AP6, BL4 and BL6) and the
flexible cable (AP9 and DG3 (TC-20LA1)/ DG4, DG5 (TC­17LA1)) and remove the screws (7 pcs) and detach the AP­Board, DG-Board and BL-Board.

Caution:

PCB Fixing screws driving torque: 0.2-0.3 N·m (2-3kg·mm)
Do not tighten screws so hard.

8.Remove the screws (2 pcs), detach the LCD panel.

18