Safety Precautions; Warning - JVC TD-W717TN Service Manual

TD - W 717 TNC
/ J
TD
-
W 718 BKA
/ B / E / EN / G
/ U / UT
Safety Precautios
1
.
The design this product contains special hardware and many circuits and
components
specially for safety purposes
.
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
.
2
.
Alterations of the design or circuitry of the product should
not
be made
.
Any design alterations of the product should
not
be made
.
Any design alterations or additions will void the manufacture ' s warranty and will further relieve the manufacture of responsibility for
personal injury or
property
damage resulting
therefrom
.
3
.
Many electrical and mechanical parts in the product have special safety
—
related characteristics
.
These characteristics 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
components
having such features are identified by shading and
(
A
\
) on the schematic
diagram and by
( ) on the
parts
list in the service manual
.
The use of a substitute replacement which does
not have the same
safety characteristics as the recommended replacement part shown in the
parts
list of service manual may
create shock , fire , or
other hazards
.
4
.
The leads in the products are routed and dressed with ties , clamps , tubings , barriers and the like
to
be separated 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 it should be confirmed that they have been returned
to
normal
,
after reassembling
.
5
.
Leakage current check ( Electrical shock hazard testing )
After re
—
assembling the product
,
always perform an isolation check on the exposed metal parts of the product (
antenna
terminals
,
knobs , metal cabinet
,
screw heads
,
headphone jack , control shafts ,
etc
.
) to be sure the product is safe
to operate
without
danger of electrical shock
.
Do not use a line isolation transformer during this check
.
• Plug the AC line cord directly into the AC outlet
,
using aTeakage
current tester " , measure the leakage current from each exposed
metal part of the cabinet
,
particulary
any exposed
metal
part
having
a return path to the chassis ,
to
a known good earth ground
.
Any leakage
current must not
exposeed
0.5
mA AC ( r
.
m
.
s
.
)
•
Alternate check method
AC VOLTMETER
(
Having 1000
ohms / volt ,
or more
sensitivity
.
)
m
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 1 , 500
ohms
10 W resistor paralleled by
a
0.15 ( 1
F 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
o
-
0.15 pF AC TYPE
ft
Place this probe
< * •
on each
exposed
metal
part
.
1500 10 W
Good earth ground
exposed metal part
,
particularly any exposed metal part having a return
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 0.75 V
AC ( r
.
m
.
s
.
)
.
This corresponds
to 0.5
mA AC
( r
.
m
.
s
.
)
.
Warning
(
UK only )
1
.
This equipment has been designed and manufactured
to meet international safety standards
.
2
.
It is the legal responsibility of the repairer
to ensure that these
safety standards
are
maintaintained
.
3
.
Repairs must be made in accordance with the relevant safety standards
.
4
.
It is essential that safety critical
components
are replaced by approved parts
.
5
.
If mains voltage selector is provided
,
check setting for local voltage
.
2 ( No
.
4358 )