Ricoh Aficio BP20N, Service Manual

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ESD PRECAUTIONS
Certain semiconductor devices can be damaged by static electricity. Such
components are commonly called “Electrostatically Sensitive (ES) Devices”, or
ESDs. Examples of typical ESDs are: integrated circuits, some field effect
transistors, and semiconductor “chip” components. The techniques outlined below
should be strictly followed to help reduce the incidence of component damage
caused by static electricity.

CAUTION
Ensure that 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 any electrostatic charge on your body by touching a
known earth ground. Alternatively, employ a commercially available wrist strap
device, which must be removed for your personal safety reasons prior to
applying power to the unit under test.
2. After removing an electrical assembly equipped with ESDs, place the assembly
on a conductive surface, such as aluminum or copper foil, or conductive foam,
to prevent electrostatic charge buildup in the vicinity of the assembly.
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” can generate electrical charges sufficient to
damage ESDs.
5. Do not use Freon-propelled chemicals. When sprayed, these can generate
electrical charges sufficient to damage ESDs.
6. Do not remove a replacement ESD from its protective packaging until
immediately prior to installing it. Most replacement ESDs are packaged with all
leads shorted together by conductive foam, aluminum foil, or a comparable
conductive material.
7. Immediately before removing the protective shorting 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.
8. Maintain continuous electrical contact between the ESD and the assembly into
which it will be installed, until the ESD or assembly is completely plugged or
soldered into the circuit.
9. Minimize bodily motions when handling unpackaged replacement ESDs.
Normal motions, such as the brushing together of clothing fabric and lifting
one’s foot from a carpeted floor, can generate static electricity sufficient to
damage an ESD.