Samsung DVD-CM420 Service Manual

Also see for CHT-420: Instruction manual Service manual Instruction manual Manual de instrucciones

Precautions1-4 Samsung Electronics1-3 ESD PrecautionsElectrostatically Sensitive Devices (ESD)Some semiconductor (solid state) devices can be dam-aged easily by static electricity.Such components commonly are called Electrostati-cally Sensitive Devices(ESD). Examples of typical ESDdevices are integrated circuits and some field-effecttransistors and semiconductor chip components. Thefollowing techniques should be used to help reducethe incidence of component damage caused by staticelectricity.(1) Immediately before handling any semiconductorcomponent or semiconductor-equipped assembly,drain off any electrostatic charge on your body bytouching a known earth ground. Alternatively,obtain and wear a commercially available dis-charging wrist strap device, which should beremoved for potential shock reasons prior to apply-ing power to the unit under test.(2) After removing an electrical assembly equippedwith ESD devices, place the assembly on a conduc-tive surface such as aluminum foil, to prevent elec-trostatic charge buildup or exposure of the assem-bly.(3) Use only a grounded-tip soldering iron to solder orunsolder ESD devices.(4) Use only 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 cangenerate electrical charges sufficient to damageESD devices.(6) Do not remove a replacement ESD device from itsprotective package until immediately before yourare ready to install it.(Most replacement ESDdevices are packaged with leads electrically short-ed together by conductive foam, aluminum foil orcomparable conductive materials).(7) Immediately before removing the protective ma-terials from the leads of a replacement ESD device,touch the protective material to the chassis or cir-cuit assembly into which the device will beinstalled.CAUTION : Be sure no power is applied to the ch-assis or circuit, and observe all other safety precau-tions.(8) Minimize bodily motions when handling unpack-aged replacement ESD devices. (Otherwise harm-less motion such as the brushing together of yourclothes fabric or the lifting of your foot from a car-peted floor can generate static electricity sufficientto damage an ESD device).All manuals and user guides at all-guides.comall-guides.com