Samsung ML-3471ND/XAX Service Manual

Also see for ML-3470D: Manual Del Usuario User guide

Contents

Samsung ElectronicsService ManualPrecautions1-41.3 ESD PrecautionsCertain semiconductor devices can be easily damaged by static electricity. Such components are commonly called“Electrostatically Sensitive (ES) Devices”, or ESDs. Examples of typical ESDs are: integrated circuits, some fieldeffect transistors, and semiconductor “chip” components.The techniques outlined below should be followed to help reduce the incidence of component damage caused bystatic electricity.Caution >>Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.1. Immediately before handling a semiconductor component or semiconductor-equipped assembly, drain off anyelectrostatic charge on your body by touching a known earth ground. Alternatively, employ a commercially avail-able wrist strap device, which should be removed for your personal safety reasons prior to applying power to theunit under test.2. After removing an electrical assembly equipped with ESDs, place the assembly on a conductive surface, suchas aluminum or copper foil, or conductive foam, to prevent electrostatic charge buildup in the vicinity of theassembly.3. Use only a grounded tip soldering iron to solder or desolder ESDs.4. Use only an “anti-static” solder removal device. Some solder removal devices not classified as “anti-static” cangenerate electrical charges sufficient to damage ESDs.5. Do not use Freon-propelled chemicals. When sprayed, these can generate electrical charges sufficient to dam-age ESDs.6. Do not remove a replacement ESD from its protective packaging until immediately before installing it. Mostreplacement ESDs are packaged with all leads shorted together by conductive foam, aluminum foil, or a compa-rable conductive material.7. Immediately before removing the protective shorting material from the leads of a replacement ESD, touch theprotective material to the chassis or circuit assembly into which the device will be installed.8. Maintain continuous electrical contact between the ESD and the assembly into which it will be installed, untilcompletely plugged or soldered into the circuit.9. Minimize bodily motions when handling unpackaged replacement ESDs. Normal motions, such as the brushingtogether of clothing fabric and lifting one’s foot from a carpeted floor, can generate static electricity sufficient todamage an ESD.