Safety Precaution - JVC RC-W305 Service Manual

RC-W305
Safety Precautions
1. This design of this product contains special hardware and many circuits and components specially for
safety purposes. For continued protection, no changes should be made ti the original design unless
authorised in writing by the manufacturer. Replacement parts must be identical to those used in the
original circuits. Services should be performed by qualified personel 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 manufacturer's warranty
and will further relieve the manufacturer of responsibility for personal injury or property damage
resulting therefrom.
3. Many eletrical and mechanical parts in the products have special safety-related characteristics.
These characteristics are often not evident from visual inspection nor can the protection afforded by
them necessarily be obtain by using replaement components rated for higher voltage, the Parts
List of Service manual. Electrical components having such features ate identified by the shading on the
!
schematics and by (
repalcement which does not have the same safety characteristics as the recommended replacement
parts 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, tubing's, barriers and the like to
be separated from live parts, high temperatures parts, moving parts and/or sharp edges for the
prevention of electric shcok and fire hazard. When service is required, the original leat routing and
dress should be observed, and it should be confirmed that they have been returned to normal, after
re-assembling.
5. Leakage current check (Electrical Shock hazard testing)
After re-assembling the product, always perform an isolation check on the exposed metap 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 isloation transformer during this check.
Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the
leakage current from each ecposed metal parts of the cabinet, particularly and exposed metal
part having a return path to the chassis, to a known good earth ground. Any leakage current must
not exceed 0.5mA 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 sensitvity in the following manner. Connect a 1,500 ohm 10W resistor paralleled by a
0.15uF 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 and exposed metal part
having a return path to te chassis and
measure the AC voltage across the resistor. Now,
reverse the plug in the AC outlet and repeat
each measurement. Voltage measured Any must
not exceed 0.75 V AC (r.m.s.). This corresponds
to 0.5 mA AC (r.m.s.).
Warning
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 maintained.
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. It mains voltage selector is provided, check setting for local voltage.
CAUTION
Burrs formed during moulding may be left over on some parts of the chassis. Therefore,
pay attention to such burrs in the case of performing repair of this system.
) on the parts List in the Service Manual. The use of a substitute
2
XL-SV320SL/SV305GD
XL-SV308BU