Panasonic VDR-D250EG, Руководство по обслуживанию

Страница: 3 / 119

damaged by the short circuit.
4. After servicing, see to it that all the protective devices such as
insulation barriers, insulation papers shields are properly installed.
5. After servicing, make the following leakage current checks to
prevent the customer from being exposed to shock hazards.
2. Warning
2.1. 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 aluminum
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 antistatic solder removal device. Some solder removal
devices not classified as “antistatic (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).
3