NAD M56 Service Manual Download

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SERVICING PRECAUTIONS

CAUTION: Before servicing the BLU-RAY DISC 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 follow-
ing servicing precautions and any of the safety precautions in
this publications, always follow the safety precautions.
Remember Safety First :

General Servicing Precautions

1. Always unplug the BLU-RAY DISC PLAYER AC power cord

from the AC power source before:

(1)

Removing or reinstalling any component, circuit board,
module, or any other assembly.

(2)

Disconnecting or reconnecting any internal electrical
plug or other electrical connection.

(3)

Connecting a test substitute in parallel with an electro-
lytic 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 BLU-RAY DISC

PLAYER or any of its assemblies.

3. Unless specified otherwise in this service data, clean electri-

cal contacts by applying an appropriate contact cleaning
solution to the contacts with a pipe cleaner, cotton-tipped
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

whitch instruments covered by this service manual might be
equipped.

5. Do not apply AC power to this BLU-RAY DISC PLAYER and

/ or any of its electrical assemblies unless all solidstate
device heat sinks are correctly installed.

6. Always connect the test instrument ground lead to an appro-

priate ground before connecting 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 blades of the attachment plug. The insulation resistance
between each blade of the attachment plug and accessible
conductive parts (Note 1) should be more than 1Mohm.

Note 1

: Accessible Conductive Parts include 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 handling any semiconductor component

or semiconductor-equipped assembly, drain off any electro-
static charge on your body by touching a known earth
ground. Alternatively, obtain and wear a commercially avail-
able 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
as 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 anti-static solder removal device. Some solder

removal devices not classified as “anti-static” can generate
electrical charges sufficient to damage ES devices.

5. Do not use freon-propelled chemicals. These can generate

an electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective

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 cir-

cuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replace-

ment 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 suf-
ficient to damage an ES device.)

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