Jvc MXK 30 R Service Manual

Page 2

-Safety Precautions

1. This design of this product contains special hardware and many circuits and components specially or
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. Services 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 manufacturers 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 products 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 on the
schematics and by (A) 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 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, 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 re-assembling.

5. Leakage currnet 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.

0 Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the
leakage current from each exposed metal parts 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 0.5mA AC (r.m.s.)

0 Alternate check method

Plug the AC line cord directly into the AC outlet. ACVOLTMETER
Use an AC voltmeter having, 1,000 ohms per volt a (Having 1000

or more sensitivity in the following manner. Con» ohms/vollsr ,. ,
nect a 1,500 010W resistor paralleled by a 0.15/1F 0' "we sensmVlil/l
AC-type capacitor between an exposed metal part

and a known good earth ground. Measure the AC 0.15uF AC TYPE

voltage across the resistor with the AC voltmeter. .
Move the resistor connection to each exposed -"- 3:22:25
metal part, particularly any exposed metal part Wt, each exposed

having a return path to the chassis, and meausre 15000 10W metal part.
the AC voltage across the resistor. Now, reverse

the plug in the AC outlet andrepeat each Goodearthground

measurement. Voltage measured Any must not

exceed 0.75 V AC (r.m.s.). This corresponds to

0.5 mA AC (r.m.s.).

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 majntai ned.
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. repair 0' "5 system.

Warning A CAUTION

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the
parts that are printed over with black such as the resistor (-), diode (1-) and ICP (O) or identified by the A mark
nearby are critical for safety.

When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer.
(Except the J and C version)

1-2

Burrs formed during molding may be
left over on some parts of the
chassis. Therefore, pay attention to
such burrs in the case of preforming