Panasonic Viera TX-26LE8A User manual

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copying and distribution is a violation of law.
TX-26LE8A
LH80 Chassis
LCD TV
Specifications
Power Source :
A
C SINGLE 230 V, 50 Hz
Power Consumption
Average Use 102 W
Standby condition 1.0 W
Display panel
Aspect Ratio 16:9
Visible screen size 576 mm (W) × 324 mm (H)
(No. of pixels) 1,049,088 (1,366 (W) × 768 (H))
Sound
Speaker Full range × 2 pcs, 8 Ω
Audio Output 20 W (10 W + 10 W), 10% THD
Headphones M3 (3.5 mm) Jack × 1
PC signals VGA, SVGA, XGA, WVGA, WXGA
Vertical scanning frequency 60 Hz
Receiving Systems / Band name SYSTEMS FUNCTIONS
———————————————————————————————————————
1PAL B, G, H
2PAL I Reception
of broadcast
transmission and
playback from
video cassette tape
recorders.
3PAL D, K
4SECAM B, G
5SECAM D, K
6SECAM K1
7NTSC M (NTSC 3.58 / 4.5 MHz)
———————————————————————————————————————
8NTSC 4.43 / 5.5 MHz Playback from
special VCR’s or DVD.
9NTSC 4.43 / 6.0 MHz
ORDER NO. MTV0801657CE

1 Safety Precautions 4
1.1. General Guidelines 4
1.2. Touch-Current Check 4
2 Prevention of Electro Static Discharge (ESD) to
Electrostatically Sensitive (ES) Devices 5
3 About Lead Free Solder (PbF) 6
4 Self Check Function 7
4.1. Self Check 7
4.2. Power LED Blinking Timing Chart 7
4.3. LED and Remote Controller Receiver Check 8
5 Chassis Board 9
5.1. Chassis Installation 9
6 Location of Lead Wiring 10
6.1. Wire Dressing 10
6.2. Wire Dressing and Connections 11
7 Disassembly for Service 12
10 NTSC 4.43 / 6.5 MHz
11 NTSC 3.58 / 5.5 MHz Playback from
special VCR’s or DVD.
12 NTSC 3.58 / 6.0 MHz
13 NTSC 3.58 / 6.5 MHz
14 SECAM I
———————————————————————————————————————
15 PAL 60 Hz / 5.5 MHz Playback from
Special Disc Players
and Special VCR’s or DVD.
16 PAL 60 Hz / 6.0 MHz
17 PAL 60 Hz / 6.5 MHz
Aerial - Rear VHF / UHF
Operation Conditions Temperature : 0°C - 40°C
Humidity : 20% -- 80% RH (non-condensing)
Connection Terminals :
AV1 AUDIO L-R RCA PIN Type × 2 0.5 V[rms]
Input VIDEO RCA PIN Type × 1 1.0 V[p-p] (75 Ω)
AV2 AUDIO L-R RCA PIN Type × 2 0.5 V[rms]
Input VIDEO RCA PIN Type × 1 1.0 V[p-p] (75 Ω)
COMPONENT Y 1.0 V[p-p] (including synchronization)
PB/C
B,P R/C R±0.35 V[p-p]
AV3 AUDIO L-R RCA PIN Type × 2 0.5 V[rms]
Input VIDEO RCA PIN Type × 1 1.0 V[p-p] (75 Ω)
S VIDEO Mini DIN 4-pin Y: 1.0 V[p-p] (75 Ω) C: 0.286 V[p-p] (75 Ω)
Others HDMI 1/2 Input TYPE A Connectors
Audio Input for
HDMI 1 RCA PIN Type × 2 0.5 V[rms]
PC Input HIGH-DENSITY D-SUB 15 PIN R, G, B / 0.7 V[p-p] (75 Ω)
HD, VD / TTL LEVEL 2.0-5.0 V[rms] (high
impedance)
Monitor AUDIO L-R RCA PIN Type × 2 0.5 V[rms] (high impedance)
Output VIDEO RCA PIN Type × 1 1.0 V[p-p] (75Ω)
Dimensions (W × H × D) 700 mm × 504 mm × 225 mm (With TV Stand)
700 mm × 466 mm × 110 mm (TV only)
Mass 12.5 kg (Net)
Design and specifications are subject to change without notice. Mass and dimensions shown are approximate.
CONTENTS
Page Page
2
TX-26LE8A

7.1. AC Code dressing for 2-Pin 12
7.2. AC Code dressing for 3-Pin 12
7.3. Chassis Rail Installation 13
7.4. VESA and Pedesdal Bracket Installation 14
7.5. Pedestal Assembly Preparation 15
7.6. LED Panel Installation 17
7.7. LCD Panel Assembly Installation 18
7.8. Back Cover and Model Name Plate Installation 19
8 Service Mode Adjustment 20
8.1. SERVICE 1 20
8.2. SERVICE 2 20
8.3. Self Check Mode 20
8.4. Hotel Mode Adjustment 20
9 Adjustment 23
9.1. Voltage Chart of A Board 23
9.2. Voltage Chart of P board 23
10 Conductor Views 24
10.1. A-Board 24
10.2. A-Board 25
11 Schematic Diagram 26
11.1. Schematic Diagram Notes 26
11.2. A Board 27
11.3. G Board 37
11.4. K Board 39
11.5. P Board 40
11.6. SW Board 44
11.7. V Board 45
12 Parts Location & Mechanical Replacement Parts List 49
12.1. Parts Location 49
13 Packing Exploded View 50
14 Replacement Parts List 51
14.1. Electrical Replacement Parts List 52
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TX-26LE8A

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.
1.2. Touch-Current Check
1.Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2.Connect a measuring network for touch currents 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 the Leakage Current Tester (Simpson 228 or equivalent) to measure the potential across the measuring network.
4.Check each exposed metallic part and measure the voltage at each point.
5.The potential at any point (touch current) expressed as voltage U1and U2, do not exceed the following values:
For AC: U1= 35 V (peak) and U2= 0.35 V (peak);
For DC: U1= 1.0 V,
NOTE :
The limit value of U2= 0.35 V (peak) for AC and U1= 1.0 V for DC correspond to the values 0.7 mA (peak) AC and 2.0 mA DC.
The limit value U1= 35 V (peak) for AC correspond to the value 70 mA (peak) AC for frequencies greater than 100 kHz.
6.Should a measurement be out 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.
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TX-26LE8A

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
aluminium 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 charges 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, aluminium 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 harmless 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).
5
TX-26LE8A

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 (PbF) used in our manufacturing process and discussed below is (Sn+Ag+Cu).
Those are Tin (Sn), Silver (Ag) and Copper (Cu), although other types are available.
This model uses PbF in its manufacture due to environmental conservation issues. For service and repair work, we would suggest
the use of PbF as well, although Pb may be used.
PCBs manufactured using lead-free will have the “PbF within a leaf Symbol” stamped on their back.
Caution
• PbF has a higher melting point than that of 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).
• PbF 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 PbF on the pins or solder area before applying Pb. If this is
not practical, be sure to heat the PbF until it melts, before applying Pb.
• After applying PbF to double layered boards, please check the component side for excess solder which may flow onto the
opposite side (see Figure 2).
Figure 2
Suggested PbF
There are several kinds of PbF available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder. However,
Sn+Cu (tin, copper) and Sn+Zn+Bi (tin, zinc, bismuth) solders can also be used.
Figure 3
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TX-26LE8A

4 Self Check Function
4.1. Self Check
1.Self Check is used to automatically check the bus lines and hexadecimal codes of the TV set.
2.To get into the Self Check mode, press the “DOWN” button on the customer’s controls at the front of the set, at the same time
pressing the “MENU” button on the remote control. The screen that will show is represented by Figure 4.
3.Press both “OFF TIMER” button on the remote control and “DOWN” key button on the control panel.
Figure 4
4.2. Power LED Blinking Timing Chart
1.Subject
Information of LED blinking timing chart.
2.Contents
When an abonormality has occurred in the unit, the protection circuit operates and resets to standby mode. At this time, the
defective block can be identified by the number of blinks of the Power LED on the front panel of the unit.
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TX-26LE8A

4.3. LED and Remote Controller Receiver Check
1.Turn on the set using the power switch.
Check that the LED on the front panel is as shown below.
Green lamp lit = Receiving
2.Turn off the power supply using the remote controller and check that the LED is as shown below.
Red lamp lit = Standby
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TX-26LE8A

5 Chassis Board
5.1. Chassis Installation
1.Fix 12 screws to ‘A-board’ and ‘P-board’.
Tightening torque should be 50 Ncm to 80 Ncm (5 kgf cm to 8 kgf cm).
2.Fix connectors G1, G2 and G3 to AT G-board.
3.Fix 2 screws to the side of AV bracket assembly.
Tightening torque should be 100 Ncm to 130 Ncm (10 kgf cm to 13 kgf cm).
4.Fix 1 screw to cabinet with power switch PCB bracket.
Tightening torque should be 100 Ncm to 130 Ncm (10 kgf cm to 13 kgf cm).
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TX-26LE8A

6 Location of Lead Wiring
6.1. Wire Dressing
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TX-26LE8A