SERVICING PRECAUTIONS
CAUTION: Before servicing the DVD+VCR covered by thisElectrostatically Sensitive (ES) Devices
service data and its supplements and addends, read and fol-Some semiconductor (solid state) devices can be damaged
low the SAFETY PRECAUTIONS. NOTE: if unforeseen cir-easily by static electricity. Such components commonly are
cumstances create conflict between the following servicingcalled Electrostatically Sensitive (ES) Devices. Examples of
precautions and any of the safety precautions in this publi-typical ES devices are integrated circuits and some field
cations, always follow the safety precautions.effect transistors and semiconductor chip components.
Remember Safety First:The following techniques should be used to help reduce the
incidence of component damage caused by static electricity.
General Servicing Precautions
1. Always unplug the DVD+VCR AC power cord from the AC1. Immediately before handling any semiconductor compo-
power source before:nent or semiconductor-equipped assembly, drain off any
(1) Removing or reinstalling any component, circuit board, electrostatic charge on your body by touching a known
module, or any other assembly.earth ground. Alternatively, obtain and wear a commer-
(2) Disconnecting or reconnecting any internal electricalcially available discharging wrist strap device, which
plug or other electrical connection.should be removed for potential shock reasons prior to
(3) Connecting a test substitute in parallel with an elec-applying power to the unit under test.
trolytic capacitor.
Caution: A wrong part substitution or incorrect 2. After removing an electrical assembly equipped with ES
polarity installation of electrolytic capacitors may resultdevices, place the assembly on a conductive surface such
in an explosion hazard.as aluminum foil, to prevent electrostatic charge buildup or
exposure of the assembly.
2. Do not spray chemicals on or near this DVD+VCR or any
of its assemblies.3. Use only a grounded-tip soldering iron to solder or unsolder
ES devices.
3. Unless specified otherwise in this service data, clean
electrical contacts by applying an appropriate contact 4. Use only an anti-static solder removal device. Some
cleaning solution to the contacts with a pipe cleaner,solder removal devices not classified as Oanti-static� can
cotton-tipped swab, or comparable soft applicator.generate electrical charges sufficient to damage ES
Unless specified otherwise in this service data, lubricationdevices.
of contacts is not required.
5. Do not use freon-propelled chemicals. These can
4. Do not defeat any plug/socket B+ voltage interlocks withgenerate an electrical charge sufficient to damage ES
whitch instruments covered by this service manual mightdevices.
be equipped.
6. Do not remove a replacement ES device from its protec-
5. Do not apply AC power to this DVD+VCR and / or any oftive package until immediately before you are ready to
its electrical assemblies unless all solid-state device heatinstall it. (Most replacement ES devices are packaged with
sinks are correctly installed.leads electrically shorted together by conductive foam,
aluminum foil,or comparable conductive material).
6. Always connect the test instrument ground lead to an
appropriate ground before connecting the test instrument
positive lead. Always remove the test instrument ground 7. Immediately before removing the protective material from
lead last.the leads of a replacement ES device, touch the protective
material to the chassis or circuit assembly into which the
Insulation Checking Proceduredevice will be installed.
Disconnect the attachment plug from the AC outlet and turn
the power on. Connect an insulation resistance meter (500V)Caution: Be sure no power is applied to the chassis or
to the blades of the attachment plug. The insulation resis-circuit, and observe all other safety precautions.
tance between each blade of the attachment plug and acces-
sible conductive parts (Note 1) should be more than 1M-8. Minimize bodily motions when handling unpackaged
ohm.replacement ES devices. (Normally harmless motion such
Note 1: Accessible Conductive Parts include Metal panels,as the brushing together of your clothes fabric or the lifting
Input terminals, Earphone jacks,etc.of your foot from a carpeted floor can generate static elec-
tricity sufficient to damage an ES device.)
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