Samsung DVD-807K, Service Manual

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Samsung Electronics 1-3
CAUTION: Before servicing Instruments covered by
this service manual and its supplements, read and fol-
low the Safety Precautions section of this manual.
Note: If unforseen circument create conflict between
the following servicing precautions and any of the
safety precautions, always follow the safety precau-
tions. Remember: Safety First.
1-2-1 General Servicing Precautions
(1) a. Always unplug the instrument’s AC power cord
from the AC power source before (1) removing
or reinstalling any component, circuit board,
module or any other instrument assembly, (2)
disconnecting any instrument electrical plug or
other electrical connection, (3) connecting a test
substitute in parallel with an electrolytic capaci-
tor in the instrument.
b. Do not defeat any plug/socker B+ voltage inter-
locks with which instruments covered by this
service manual might be equipped.
c. Do not apply AC power to this instrument and/or
any of its electrical assemblies unless all solid-
state device heat sinks are correctly installed.
d. Always connect a test instrument’s ground lead
to the instrument chassis ground before con-
necting the test instrument positive lead. Always
remove the test instrument ground lead last.
Note: Refer to the Safety Precautions section ground
lead last.
(2) The service precautions are indicated or printed on
the cabinet, chassis or components. When servic-
ing, follow the printed or indicated service precau-
tions and service materials.
(3) The components used in the unit have a specified
flame resistance and dielectric strength. When
replacing components, use components which
have the same retings. Components identified by
shading, by( x ) or by (
) in the circuit diagram
are important for safety or for the characteristics of
the unit. Always replace them with the exact
replacement components.
(4) An insulation tube or tape is sometimes used and
some components are raised above the printed wil-
ing board for safety. The internal wiring is some-
times clamped to prevent contact with heating com-
ponents. Install such elements as they were.
(5) After servicing, always check that the removed
screws, corponents, and wiring have been installed
correctly and that the portion around the serviced
part has not been damaged and so on. Further,
check the insulation between the blades of the
attachment plug and accessible conductive parts.
1-2-2 Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and
turn the power ON. Connect the insulation resistance
meter (500V) to the blades of the attachment plug. The
insulation resistance between each blade of the
attachment plug and accessible conductive parts(see
note) should be more than 1 Megohm.
Note: Accesible conductive parts include metal pan-
els, input terminals, earphone jacks, etc.
1-2 Servicing Precautions