Samsung HW-T450, Service Manual

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1-3. Precautions for Electrostatically Sensitive Devices (ESDs)
• Some semiconductor (“solid state”) devices are easily damaged by static electricity.
Such components are called Electrostatically Sensitive Devices (ESDs). Examples include integrated circuits and some
field-effect transistors. The following techniques will reduce the occurrence of component damage caused by static
electricity.
1. Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your
body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. (Be sure to remove it prior to
applying power-this is an electric shock precaution.)
2. After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation
of electrostatic charge.
3. Do not use freon-propelled chemicals. These can generate electrical charges that damage ESDs.
4. Use only a grounded-tip soldering iron when soldering or unsoldering ESDs.
5. Use only an anti-static solder removal device. Many solder removal devices are not rated as “anti-static” (these can
accumulate sufficient electrical charge to damage ESDs).
6. Do not remove a replacement ESD from its protective package until you are ready to install it.
Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or
other conductive materials.
7. Immediately before removing the protective material from the leads of a replacement ESD, 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 body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting
your foot from a carpeted floor can generate enough static electricity to damage an ESD.