SERVICING PRECAUTIONS
CAUTION : Before servicing the DVD covered by this Electrostatically Sensitive (ES) Devices
service data and its supplements and ADDENDUMS, read
Some semiconductor (solid state) devices can be damaged
and follow the SAFETY PRECAUTIONS NOTE : if easily by static electricity. Such components commonly are
unforeseen circumstances create conflict between the
called Electrostatically Sensitive (ES) Devices. Examples of
following servicing precautions and any of the safety typical ES devices are integrated circuits and some field
precautions in this publications, always follow the safety
effect transistors and semiconductor chip components.
precautions.The following techniques should be used to help reduce the
Remember Safety First:
incidence of component damage caused by static electricity.
General Servicing Precautions1. Immediately before handling any semiconductor
1. Always unplug the DVD AC power cord from the AC component or semiconductor-equipped assembly, drain
power source before:off any electrostatic charge on your body by touching a
(1) Removing or reinstalling any component, circuit board, known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device,
module, or any other assembly.which should be removed for potential shock reasons
(2) Disconnection or reconnecting any internal electrical
prior to applying power to the unit under test.
plug or other electrical connection.
(3) Connecting a test substitute in parallel with an 2. After removing an electrical assembly equipped with ES
electrolytic capacitor
devices, place the assembly on a conductive surface
Caution : A wrong part substitution or incorrect such as aluminum toil, to prevent electrostatic charge
polarity installation of electrolytic capacitors may
buildup or exposure of the assembly.
result in an explosion hazard.
3. Use only a GROUNDED-tip soldering iron to solder or
2. Do not spray chemicals on or near this DVD or any of its
unsolder ES devices.
assemblies.
4. Use only an anti-static solder removal device. Some
3. Unless specified otherwise in this service data, clean
solder removal devices not classified a "anti-static" can
electrical contacts by applying an appropriate contact generate electrical charges sufficient to damage ES
cleaning solution to the contacts with a pipe cleaner,
devices.
cotton-tipped swab, or comparable soft applicator.
Unless specified otherwise in this service data, 5. Do not use freon-propelled chemicals. These can
lubrication of contacts is not required.
generate electrical charge sufficient to damage ES
devices.
4. Do not defeat any plug/socket B+ voltage interlocks with
witch instruments covered by this service manual might
6. Do not remove a replacement ES device from its
be equipped.protective package until immediately before you are
ready to install it. (Most replacement ES devices are
5. Do not apply AC power to this DVD and/or any of its packaged with leads electrically shorted together by
electrical assemblies unless all solid-state device heat conductive foam, aluminum foil, or comparable
sinks are correctly installed.conductive material.)
6. Always connect test instrument ground lead to the 7. Immediately before removing the protective material
appropriate ground before connection the test from the leads of a replacement ES device, touch the
instrument positive lead. Always remove the test protective material to the chassis or circuit assembly
instrument ground lead last.into which the device will be installed.
Insulation Checking ProcedureCaution : Be sure no power is applied to the chassis or
Disconnect the attachment plug trom the AC outlet and turn circuit, and observe all other safety precautions.
the power on. Connect an insulation resistance meter(500V)
to the blades of the attachment plug. The insulation
8. Minimize bodily motions when handling unpackaged
resistance between each blade of the attachment plug and replacement ES devices. (Normally harmless motion
accessible conductive parts (Note 1) should be more than
such as the brushing together of your clothes fabric or the
1M ohm.lifting of your foot from a carpeted floor can generate
Note 1 : Accessible Conductive Parts including Metal static electricity sufficient to damage an ES device.)
panels, input terminals, Earphone jacks, etc.
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ACEC
