Safety Precautions; Service Precautions - JVC A-GX1 Service Manual

Stereo integrated amplifier
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\-GX1/A-GX1B
Safety Precautions
1. The design of this product contains special hardware,
duct is safe to operate
without
danger
of electrical
many circuits and components specially for safety pur-
poses.
For continued protection, no changes should be made
to the original design unless authorized
in writing by
the manufacturer.
Replacement parts must be identical
to those used in the original circuits. Service should be
performed by qualified personnel only.
. Alterations of the design
or circuitry of the product
should not be made.
Any design alterations or addi-
tions will void the manufacturer's
warranty
and will
further relieve the manufacturer
of responsibility for
personal injury or property damage resulting therefrom.
. Many
electrical and mechanical
parts in the product
have special safety-related characteristics.
These char-
acteristics are often not evident from visual inspection
nor can the protection afforded by them necessarily be
obtained
by using replacement components
rated for
higher voltage, wattage, etc. Replacement parts which
have these special safety characteristics are identified
in the parts list of Service manual.
Electrical compo-
nents having such features are identified by shading on
the schematics and by ( A ) on the parts list in Service
manual.
The use of a substitute
replacement
which
does not have the same safety characteristics as the re-
commended replacement part shown in the parts list in
Service manual may create shock, fire, or other hazards.
. The leads in the products are routed and dressed with
ties, clamps, tubings, barriers and/or the like to be sep-
arated from live parts, high temperature parts, moving
parts and/or sharp edges for the prevention of electric
shock and fire hazard.
When
service is required, the original lead routing and
dress
should
be observed,
and they should
be con-
firmed to be returned to normal, after reassembling.
. Leakage current check
(Safety for electrical shock hazard)
After reassembling the product, always perform an iso-
lation check on the exposed metal parts of the Products
(antenna terminals, Knobs, metal cabinet, screw heads,
headphone jack, control shafts, etc.) to be sure the pro-
Service Precautions
1. Before repairing, be sure to discharge the large electro-
lytic Capacitors across a resistor of about 100 ohms/1
watt.
m@ When disassembling
1. When
replacing a power transistor or IC, be sure to
apply silicone grease to the section of a new transistor
or IC whichis in close contact with the heatsink, then
mount it.
1-1 (No. 2810)
CHECKING YOUR LINE VOLTAGE (For U.S. Military Market and Other Countries)
Before inserting the power plug, please check this setting to see that it corresponds with the line voltage
in your area. If it doesn't be sure to adjust the voltage selector switch to the proper setting before operat-
ing this equipment.
The voltage selector switch is located on the rear panel.
CAUTION:
Before selecting the "Voltage selector switch" to proper voltage disconnect the power plug.
shock.
Do
not
use a line isolation
transformer
during
this
check.
|
@ Plug the AC line cord directly into the AC outlet. Us-
ing a "Leakage Current Tester', measure the leakage
current from each exposed metal part of the cabinet,
particularly any exposed metal part having a return
path to the chassis, to a known good earth ground.
Any leakage current must not exceed 0.5 mA AC
(r.m.s.).
@ Alternate check method.
Plug the AC line cord directly into the AC outlet. Use
an AC voltmeter having
1,000 ohms per volt or more
sensitivity
in the
following
manner.
Connect
a
15002
10W
resistor paralleled by a 0.15 uF AC-
type capacitor between an exposed metal part and a
known good earth ground.
Measure the AC voltage across the resistor with the
AC voltmeter.
Move the resistor connection to each exposed metal
part, particularly any exposed metal part having a re-
turn path to the chassis, and measure the AC voltage
across the resistor. Now, reverse the plug in the AC
outlet and repeat each measurement.
Any voltage
measured must not exceed 0.75V AC (r.m.s.).
This corresponds to 0.5 mA AC (r.m.s.).
AC VOLTMETER
(HAVING 1000.2/V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
> ON EACH EXPOSED
METAL PART
15002 10W
GOODEARTH GROUND
Fig. 1
2. When remeving or stretching wires on the P. C. Board,
be sure to restore them to their original routing as far as
possible.

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