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 touch current checks to prevent the customer from being exposed to shock hazards.
4. Always ensure panel TKKL5290 is correctly replaced before returning to customer (see Fig.1).
Fig. 1
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 go od earth
ground such as a water pipe, as shown in Fig. 2.
3. Use 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. Reserve the AC plug in the AC outlet and repeat each of the above measure.
6. The potential at any point (TOUCH CURRENT) expressed as voltage U1 and U2, does not exceed the following values:
For a. c.: U1 = 35 V (peak) and U2 = 0.35 V (peak);
For d. c.: U1 = 1.0 V,
Note:
The limit value of U2 = 0.35 V (peak) for a. c. and U1 = 1.0 V for d. c. correspond to the values 0.7 mA (peak) a. c. and
2.0 mA d. c.
The limit value U1 = 35 V (peak) for a. c. correspond to the value 70 mA (peak) a. c. for frequencies greater than 100
kHz.
7. In case a measurement is 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.
Measuring network for TOUCH CURRENTS
COLD
WATER PIPE
(EARTH GROUND)
Fig. 2
CS=500µF
10k
U
1
0.022µF
V
U2 (V)
RS=500
TO
PPLIANCES
EXPOSED
METAL PARTS
Resistance values in ohms (Ω)
V: Voltmetr or oscilloscope
(r.m.s. or peak reading)
NOTE – Appropriate measures should be taken to obtain the correct value in case of non-sinusoidal waveforms
Input resistance: ≥ 1M
Input capacitance: ≤ 200pF
Frequency range: 15Hz to 1MHz and d.c.respectively
R0=500
3
Prevention of Electrostatic 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 electrostatic 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 commerciall y av ailable 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 build up 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 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).
IMPORTANT SAFETY NOTICE
There are special components used in this equipment which are important for safety.
These parts are marked by in schematic diagrams, exploded views and replacement parts list. It is essential that
these critical parts should be replaced with manufacturer’s specified parts to prevent shock, fire, or other hazards. Do
not modify the original design without permission of manufacturer.
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 s
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
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 so
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 Fig.3)
older, and PbF will refer to Lead Free Solder.
lder on the pins or solder area before
Fig.3
Suggested Pb free solder
There are several kinds of Pb free solder available for purchase. T
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used. (see Fig.4)
his product uses Sn+Ag+Cu (tin, silver, copper) solder.
Fig.4
5
Service Hints
How to remove the Pedestal assembly
Lay the main unit face down. (see Fig.5)
Fig.5
Remove the 2 fixing screws and hinge cover. (see Fig.6)
Remove the 8 fixing screws and the pedestal assembly. (see Fig.7)
SCREWS
Fig.6
How to remove the backcover
Remove the 2 fixing screws and hinge cover. (see Fig.6)
Remove the 16 fixing screws. (see Fig.8)
Carefully remove the backcover and disconnect two AV3 wires. (see Fig.9)
Self-check is used to automatically check the bus lines and hexadecimal code of the TV set. To enter Self-Check mode, kee p
pressing the STATUS button on the remote control and press the down (-/v) button on the TV set. To exit Self Check,
switch off the TV set at the power button.
If the CCU ports have been checked and found to be incorrect or not located then " - - " will appear in place of "O.K.".
8
Adjustment Method
How to enter Service 1
•Set the Bass to maximum position, set the Treble to minimum position then keep pressing the INDEX button on the
remote control and press the down button (-/v) on the TV set, this will place the TV set into the Service Mode 1.
Key Command
• Press the RED/GREEN buttons to step up / down through the functions.
• Press the YELLOW/BLUE buttons to alter the function values, to alter White Rasters use +/- buttons
• Press the OK button after each adjustment has been made to store the required values.
• To exit the Service Mode, press the "N" button.
Keep adjusting sequence: DVCO, Sub-Contrast, other items.
Item
Sub-Contrast
DVCO
Highlight
Lowlight
Sub-Brightness
Note: All setting values are approximate
High12041504100425
Low4005600640043
Setting indication
Sub-Contrast
23
DVCO
4
Sub-Brightness
0
Settings / Special features
Receive a 80% white level Philips Pattern with correct
sound sy
Contrast alignment press "Blue" button, wait until the
figure colour is changed from red to black colour.
Receive a 80% white level Philips Pattern via aerial
inp
until the figure colour is changed from red to black
For correct setting see W
stem (B/G, D/K) via aerial input. For Sub-
Press the OK.
ut. For DVCO alignment press "Blue" button, wait
colour. Press the OK.
hite Balance Adjustment
Optimum setting.
White Balance Adjustment
Instrument
• Remote Control
• LCD WB meter (Minolta CA-210 or equivalent)
Condition
• Switch on the TV Set. Enter Service1. Step down to Highlight line and keep the aging time more than 20 minutes.
Procedure
•After aging time above set White Raster No.12 for Highlight and No.4 for LowlightPress the OK button
to store.
•Put Minolta Sensor to the center of the LCD Panel with 25mm gap between Minolta Sensor and LCD Panel. Adjust "x"
and "y" values by changing Red and Blue values.
The numbers on the exploded view below refer to the exploded view section of the Replacement Parts List.
21
13
16
26
19
9
10
20
3
6
5
4
8
25
24
27
17
7
22
11
27
28
12
15
23
2
1
14
18
13
Components Identified by mark have special characteristics important for safety.
* When replacing any of these components, use only manufacturers specified parts.
In case of ordering these spare parts, please always add the complete Model-Type
number to your order.
DescriptionCct RefParts NumberDescriptionCct RefParts Number
COMMON PARTS
EXPLODED VIEW
SPEAKER 1EAS12S11B
TUNER 2ENG37A21GF
REMOTE CONTROL 3EUR7651030A
KEY BUTTON MODULE 4K0RB00500002
PEDESTAL ASSY 5TBLA0194
PANASONIC BADGE 6TBMA180
POWER BUTTON 7TBX0E81700
POWER BUTTON PANEL 8TKK0E9518
CONNECTOR COVER 9TKKL5290
HINGE COVER 10TKP0E15501
WALL MOUNT METAL 11TKZ0E9901
TUNER COVER 12TMW0E107
AV3 BRACKET 13TMW0E502
V P.C.B. 14TNP8EVL40AC
CHASSIS FRAME 15TUA0E400
AC CORD ASSY 16TXASX01AERE