SECTION 1
PRECAUTIONS
1.1 Safety Precautions
(1) This design of this product contains special hardware andvoltmeter.
many circuits and components specially for safety purpos-Move the resistor connection to each exposed metal
es. For continued protection, no changes should be madepart, particularly any exposed metal part having a return
to the original design unless authorized in writing by thepath to the chassis, and measure the AC voltage across
manufacturer. Replacement parts must be identical tothe resistor. Now, reverse the plug in the AC outlet and
those used in the original circuits. Services should be per-repeat each measurement. Voltage measured any must
formed by qualified personnel only.not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5?
mA AC (r.m.s.).
(2) Alterations of the design or circuitry of the product should
AC VOLTMETER
not be made. Any design alterations of the product should(Having 1000
not be made. Any design alterations or additions will voidohms/volts,
the manufacturers warranty and will further relieve theor more sensitivity)
manufacture of responsibility for personal injury or property
damage resulting therefrom.0.15 F AC TYPE
Place this
(3) Many electrical and mechanical parts in the products haveprobe on
special safety-related characteristics. These characteris-each exposed
tics are often not evident from visual inspection nor can the1500 10Wmetal part.
protection afforded by them necessarily be obtained by us-
Good earth ground
ing replacement components rated for higher voltage, watt-
age, etc. Replacement parts which have these special
safety characteristics are identified in the Parts List of Ser-
1.2 Warning
vice Manual. Electrical components having such features
(1) This equipment has been designed and manufactured to
are identified by shading on the schematics and by ( ) on
the Parts List in the Service Manual. The use of a substitutemeet international safety standards.
replacement which does not have the same safety charac-(2) It is the legal responsibility of the repairer to ensure that
these safety standards are maintained.
teristics as the recommended replacement parts shown in
the Parts List of Service Manual may create shock, fire, or(3) Repairs must be made in accordance with the relevant
other hazards.safety standards.
(4) It is essential that safety critical components are replaced
by approved parts.
(4) The leads in the products are routed and dressed with ties,
clamps, tubings, barriers and the like to be separated from(5) If mains voltage selector is provided, check setting for local
live parts, high temperature parts, moving parts and/orvoltage.
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 confirmed1.3 Caution
that they have been returned to normal, after reassem-Burrs formed during molding may be left over on some parts
bling.of the chassis.
Therefore, pay attention to such burrs in the case of pre-
(5) Leakage shock hazard testingforming repair of this system.
After reassembling the product, always perform an isola-
tion check on the exposed metal parts of the product (an-
tenna terminals, knobs, metal cabinet, screw heads,1.4 Critical parts for safety
headphone jack, control shafts, etc.) to be sure the productIn regard with component parts appearing on the silk-screen
is safe to operate without danger of electrical shock.Do not
printed side (parts side) of the PWB diagrams, the parts that are
use a line isolation transformer during this check.
printed over with black such as the resistor ( ), diode ( )
? Plug the AC line cord directly into the AC outlet. Using a
"Leakage Current Tester", measure the leakage currentand ICP ( ) or identified by the " " mark nearby are critical
for safety. When replacing them, be sure to use the parts of the
from each exposed metal parts of the cabinet, particular-
same type and rating as specified by the manufacturer.
ly any exposed metal part having a return path to the
chassis, to a known good earth ground. Any leakage cur-(This regulation dose not Except the J and C version)
rent 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& per volt or more sensitivity
in the following manner. Connect a 1,500& 10W resistor
paralleled by a 0.15?F AC-type capacitor between an ex-
posed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
(No.MB014)1-3 |
ACEC
