1-5
SERVICING PRECAUTIONS
CAUTION:
Before servicing the DVD player covered by this service
data and its supplements and addends, read and follow
the SAFETY PRECAUTIONS. NOTE: if unforeseen
circumstances create conflict between the following
servicing precautions and any of the safety precautions in
this publications, always follow the safety precautions.
Remembers Safety First:
General Servicing Precautions
1. Always unplug the DVD player AC power cord from the AC
power source before:
(1) Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2) Disconnection or reconnecting any internal electrical
plug or other electrical connection.
(3) Connection a test substitute in parallel with an
electrolytic capacitor.
Caution
:
A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an
explosion hazard.
2. Do not spray chemicals on or near this DVD player or
any of its assemblies.
3. Unless specified otherwise in this service data, clean
electrical contacts by applying an appropriate contact
cleaning solution to the contacts with a pipe cleaner,
cottontipped swab, or comparable soft applicator.
Unless specified otherwise in this service data, lubrication
of contacts is not required.
4. Do not defeat any plug/socket B+ voltage interlocks
with which instruments covered by this service manual
might be equipped.
5. Do not apply AC power to this DVD player and/or any
of its electrical assemblies unless all solid-state device
heat sinks are correctly installed.
6. Always connect test instrument ground lead to the
appropriate ground before connection the test instrument
positive lead. Always remove the test instrument ground
lead last.
Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and
turn the power on. Connect an insulation resistance
meter (500V) to the blade of the attachment plug. The
insulation resistance between each blade of the
attachment plug and accessible conductive parts (Note 1)
should be more than 1M-ohm.
Note 1:
Accessible Conductive Parts including Metal
panels, Input terminals, Earphone jacks, etc.
Electrostatically Sensitive (ES) Devices
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 static electricity.
1. Immediately before handing any semiconductor
component or semiconductor equipped assembly, drain
off any electrostatic charge on your body by touching a
known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device,
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
an 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 antistatic solder removal device. Some
solder removal devices not classified an “antistati c” can
generate electric charges sufficient to damage ES
devices.
5. Do not use freonpropelled chemicals. These can
generate electrical charge sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its protect
tive 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 comparable conductive material).
7. Immediately before removing the protective material
from the leads of a replacement ES device, 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 handing unpackaged
replacement ES devices. (Normally 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 sufficient to damage an ES device.)
