TX-20LA5F, TX-20LA5P (serv.man3) - Panasonic TV Service Manual (repair manual). Page 3

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 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 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.

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).

TO
APPLIANCES
EXPOSED
METAL PARTS

Resistance values in ohms (

Ω)

V

R

0

=500

Ω

R

S

=500

Ω

C

S

=500

µF

10k

Ω

0.022

µF

U

1

COLD
WATER PIPE
(EARTH GROUND)

V: Voltmetr or oscilloscope

(r.m.s. or peak reading)

Input resistance: 

≥ 1MΩ

Input capacitance:

 ≤ 200pF

Frequency range: 15Hz to 1Mhz and d.c.respectively

NOTE – Appropriate measures should be taken to obtain the correct value in case of non-sinusoidal waveforms

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.

U

2

 (V)