Sony D910B, Руководство по обслуживанию

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2 SERVICING PRECAUTIONS
CAUTION: Before servicing units covered by this service manual
and its supplements, read and follow the Safety Precautions section of
this manual.
Note:
If unforseen circumstances create conflict between the following
servicing precautions and any of the safety precautions, always follow
the safety precautions. Remember: Safety First.
2-1 General Servicing Precautions
(1) a. Always unplug the instrument’s AC power cord from the AC
power source before (1) re-moving 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 capacitor in the instrument.
b. Do not defeat any plug/socket B+ voltage interlocks 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 connecting 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 servicing, follow the printed or
indicated service precautions 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
ratings. Components identified by shading, by (
) 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 wiring board for safety. The internal
wiring is sometimes clamped to prevent contact with heating
components. Install such elements as they were.
(5) After servicing, always check that the removed screws,
components, 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.
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: Accessible conductive parts include metal panels, input
terminals, earphone jacks, etc.