Samsung DVD-907, Service Manual

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1-4 Samsung Electronics
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be
damaged easily by static electricity.
Such components commonly are called Electro stati-
cally Sensitive Devices(ESD). Examples of typical
ESD devices are integrated circuits and some fieldef-
fect transistors and semiconductor chip components.
The following techniques should be used to help
reduce the incidence of component damage caused
by static electricity.
(1) Immediately before handling any semiconductor
component or semiconductor-equipped assembly,
drain off any electrostatic aharge on your body by
touching a known earth ground. Alternatively,
obtain and wear a commercially available dis-
charging wrist strap device, which should be
removed for potential shock reasons prior to apply-
ing power to the unit under test.
(2) After removing an electrical assembly equipped
with ESD devices, place the assembly on a con-
ductive 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 ESD devices.
(4) Use ouly an anti-static solder removal devices.
Some solder removal devices not classified as
“anti-static” can generate electrical charges suffi-
cient to damage ESD devices.
(5) Do not use freon-propelled chemicals. These can
generate electrical charges sufficient to damge
ESD devices.
(6) Do not remove a replacement ESD device from its
protective package until immediately before your
are ready to install it.(Most replacement ESD
devices are packaged with leads electrically short-
ed together by condutive foam, aluminum foil or
comparable conductive materials).
(7) Immediately before removing the protective mate-
rials from the leads of a replacement ESD device,
touch the protective material to the chassis or cir-
cuit 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 unpack-
aged replacement ESD devices. (Otherwise harm-
less motion such as the brushing together of your
clothes fabric or the lifting of your foot from a car-
peted floor can generate static electrictity suffcient
to damage an ESD device).
1-3 ESD Precautions