Yamaha CDX-E410, Service Manual

CDX-E410

4

CDX-E410

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PREVENTION OF ELECTROSTATIC DISCHARGE

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 anti-static solder removal device. Some solder removal devices not classified as “anti-static (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 compa-

rable conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES divice, touch the protective material

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 the

brushing 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).

Grounding for electrostatic breakdown prevention

1. Human body grounding.

Use the antistatic wrist strap to discharge the static electricity from your body.

2. Work table grounding.

Put a conductive material (sheet) or steel sheet on the area where the optical pickup is placed and ground the sheet.

Caution:

The static electricity of your clothes will not be grounded through the wrist strap. So take care not to let your clothes touch the

optical pickup.

1M-ohms

Conductive material
(sheet) or steel sheet

Anti-static wrist strap