SLV-D920B, SLV-D920E, SLV-D920N, SLV-D920R, SLV-D925E, SLV-D930D, SLV-D930GI, SLV-D960PB, SLV-D960PE - Sony VCR Service Manual (repair manual). Page 5

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1) Before returning an instrument to the customer, always make a

safety check of the entire instrument, including, but not limited
to, the following items:

(1) Be sure that no built-in protective devices are defective or have

been defeated during servicing.
(1)Protective shields are provided to protect both the technician
and the customer. Correctly replace all missing protective shields,
including any removed for servicing convenience.
(2)When reinstalling the chassis and/or other assembly in the
cabinet, be sure to put back in place all protective devices,
including, but not limited to, nonmetallic control knobs, insulating
fish papers, adjustment and compartment covers/shields, and
isolation resistor/capacitor networks. Do not operate this
instrument or permit it to be operated without all protective devices
correctly installed and functioning.

(2) Be sure that there are no cabinet openings through which adults

or children might be able to insert their fingers and contact a
hazardous voltage. Such openings include, but are not limited to,
excessively wide cabinet ventilation slots, and an improperly fitted
and/or incorrectly secured cabinet back cover.

(3) Leakage Current Hot Check-With the instrument completely

reassembled, plug the AC line cord directly into a 120V AC outlet.
(Do not use an isolation transformer during this test.) Use a leakage
current tester or a metering system that complies with American
National Standards institute (ANSI) C101.1 Leakage Current for
Appliances and Underwriters Laboratories (UL) 1270 (40.7). With
the instrument’s AC switch first in the ON position and then in the
OFF position, measure from a known earth ground (metal water
pipe, conduit, etc.) to all exposed metal parts of the instrument
(antennas, handle brackets, metal cabinets, screwheads, metallic
overlays, control shafts, etc.), especially any exposed metal parts
that offer an electrical return path to the chassis.
Any current measured must not exceed 0.5mA. Reverse the
instrument power cord plug in the outlet and repeat the test. See
Fig. 1.
Any measurements not within the limits specified herein indicate
a potential shock hazard that must be eliminated before returning
the instrument to the customer.

(4) Insulation Resistance Test Cold Check-(1) Unplug the power

supply cord and connect a jumper wire between the two prongs of
the plug. (2) Turn on the power switch of the instrument. (3)
Measure the resistance with an ohmmeter between the jumpered
AC plug and all exposed metallic cabinet parts on the instrument,
such as screwheads, antenna, control shafts, handle brackets, etc.
When an exposed metallic part has a return path to the chassis, the
reading should be between 1 and 5.2 megohm. When there is no
return path to the chassis, the reading must be infinite. If the reading
is not within the limits specified, there is the possibility of a shock
hazard, and the instrument must be repared and rechecked before
it is returned to the customer. See Fig. 2.

DEVICE

UNDER

TEST

(READING SHOULD

NOT BE ABOVE

0.5mA)

LEAKAGE

CURRENT

TESTER

EARTH

GROUND

TEST ALL

EXPOSED METER

SURFACES

ALSO TEST WITH
PLUG REVERSED

(USING AC ADAPTER
PLUG AS REQUIRED)

2-WIRE CORD

Fig. 1 AC Leakage Test

Fig. 2 Insulation Resistance Test

2) Read and comply with all caution and safety related notes on or

inside the cabinet, or on the chassis.

3) Design Alteration Warning-Do not alter or add to the mechanical

or electrical design of this instrument. Design alterations and
additions, including but not limited to, circuit modifications and
the addition of items such as auxiliary audio output connections,
might alter the safety characteristics of this instrument and create
a hazard to the user. Any design alterations or additions will make
you, the servicer, responsible for personal injury or property
damage resulting therefrom.

4) Observe original lead dress. Take extra care to assure correct lead

dress in the following areas:
(1) near sharp edges, (2) near thermally hot parts (be sure that
leads and components do not touch thermally hot parts), (3) the
AC supply, (4) high voltage, and (5) antenna wiring. Always inspect
in all areas for pinched, out-of-place, or frayed wiring, Do not
change spacing between a component and the printed-circuit board.
Check the AC power cord for damage.

5) Components, parts, and/or wiring that appear to have overheated

or that are otherwise damaged should be replaced with components,
parts and/ or wiring that meet original specifications.
Additionally, determine the cause of overheating and/or damage
and, if necessary, take corrective action to remove any potential
safety hazard.

Antenna
Terminal

Exposed
Metal Part

ohm

ohmmeter