Harman Kardon HD7725 - Safety Precautions

SAFETY PRECAUTIONS
Before returning an instrument to the customer, always
make a safety check of the entire instrument, including, but not
limited to, the following items:
a. Be sure that no built-in protective devices are defective and/
or have been defeated during servicing.
(1) Protective shields are provided to protect both the
technician and the customer. Correctly replace all missing
protective shields, including any removed for servicing
convenience.
(2) When reinstalling the chassis and/or other assembly in
the cabinet, be sure to put back in place all protective
devices, including, but not limited to, nonmetallic control
knobs, insulating fisnpapers, adjustment and compartment
covers/shields, and isolation resistor/capacitor networks.
Do not operate this instrument or permit it to be
operated without all protective devices correctly
installed and functioning.
b. Be sure that there are no cabinet openings through which an
adult or child might be able to insert their fingers and contact
a hazardous voltage. Such openings include, but are not
limited to, excessively wide cabinet ventilation slots, and an
improperly fitted and/or incorrectly secured cabinet back cover.
c. Leakage Current Hot Check - With the instrument completely
reassembled, plug the AC line cord directly into a 120V AC
outlet (do not us an isolation transformer during this test).
Use a leakage current tester or a metering system that
complies with American National Standards Institute (ANSI)
101.1 "Leakage Current for Appliances" and Underwriters
Laboratories (UL) 1270, (84.6). With the instrument AC switch
first in the ON position and then in the OFF position, measure
from a known earth ground (metal waterpipe, conduit, etc.) to
all exposed metal parts of the instrument (antennas, handle
bracket, metal cabinet, screwheads, metallic overlays, control
shafts, etc.), especially any exposed metal parts that offer an
electrical retum path to the chassis. Any current measured
must not exceed 0.5 milliamp. Reverse the instrument power
cord plug in the outlet and repeat test. ANY
MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED
HEREIN INDICATE A POTENTIAL SHOCK HAZARD
AC LEAKAGE TEST
SURSENT
(READING
SHOULD
TESTER
NOT
BE
ABOVE
DEVICE 0.5mA)
UNDER
TEST
™
TEST ALL
EXPOSED METAL
SURFACES
2-WIRE CORD
©
() | atso Test with
PLUG REVERSED
(USING ADAPTER HE
PLUG AS REQUIRED)
THAT MUST BE ELIMINATED BEFORE RETURNING THE
INSTRUMENT TO THE CUSTOMER.
d. Insulation Resistance Test
(1) Unplug the power supply cord and connect a jumper wire
between the two prongs of the plug.
(2) Turn on the power switch of the instrument.
(3) Measure the resistance with an ohmmeter between the
jumpered AC plug and each exposed metallic cabinet
part on the instrument, such as screwheads, antenna,
control shafts, handle brackets, ete. The reading should
be as shown below. If it is not within the limits specified,
there is the possibility of a shock hazard, and the
instrument must be repaired and rechecked before it is
retumed to the customer.
e. Insulation Resistance Test Cold Check
(1) Unplug the power supply cord and connect a jumper wire
between the two prongs of the plug.
(2) Turn on the power switch of the instrument.
(3) Measure the resistance with an ohmmeter between the
jumpered AC plug and each exposed metallic cabinet
part on the instrument, such as screw heads, antenna,
control shafts, handle brackets, etc. When the exposed
metallic part has a return path to the chassis, the reading
should be between 1 and 5.2 Megohm. When there is no
return path to the chassis, the reading must be "infinite".
ANTENNA
TERMINAL “}} 5
OHM METER
If it is not within the limits specified, there is the possibility
of a shock hazard, and the instrument must be repaired
and rechecked before it is returned to the customer.
PRODUCT SAFETY NOTICE
Some electrical and mechanical parts have special safety-related
characteristics which are often not evident from visual inspection,
nor can the protection they give necessarily be obtained by
replacing them with components rated for higher voltage, wattage,
etc. Parts that have special safety characteristics are identified by
shading, by ( A\ ) on schematics and parts list. Use of a
substitute replacement that does not have the same safety
characteristics and parts listed. Use of a substitute replacement
that does not have the same safety characteristics as the
recommended replacement part might create shock, fire, and/or
other hazards. Products Safety is under review continuously and
new instructions are issued whenever appropriate.
SERVICING PRECAUTIONS
CAUTION: Before servicing instruments covered by this manual
and its supplements, read and follow the SAFETY
PRECAUTIONS on this page.