Panasonic SA-BTT405P Service Manual

4There are special components used in this equipment which are important for safety. These parts are marked byin the Schematic Diagrams, Circuit Board Diagrams, Exploded View and Replacement Parts List, It is essential thatthese critical parts should be replaced with manufacturer’s specified, parts to prevent shock, fire or other hazards, Donot modify the original design without permission of manufacturer.IMPORTANT SAFETY NOTICE2 Warning2.1. Prevention of Electrostatic Discharge (ESD) to ElectrostaticallySensitive (ES) DevicesSome semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are calledElectrostatically Sensitive (ES) Devices.Examples of typical ES devices are IC(integrated circuits)and some field-effect transistors andsemiconductor “chip” components.The following techniques should be used to help reduce the incidence of component damage caused by electrostaticdischarge(ESD).1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD onyour body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESDwrist 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 asaluminum 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 orcomparable conductive material).7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protectivematerial 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 thebrushing 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).