Hyundai HE-DX330, Service Manual

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1. PRECAUTIONS
1-1 Safety Precautions
1) Before returning an instrument to the customer, always
make a safety check of the entire instrument, including, but
not limited to, the following items:
(1) Be sure that no built-in protective devices are defective
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 remove 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 fish papers,
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.
(2) Be sure that there are no cabinet opening through which
adults or children 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.
(3) Leakage Current Hot Check-With the instrument
completely reassembled, plug the AC line cord
directly into a 120V AC outlet. (Do not use an
isolation transformer during this test.) Use a leakage
current tester or a metering system that complies with
American National Standards institute (ANSI) C101.1
Leakage.
Current for Appliances and underwriters Laboratories
(UL) 1270 (40.7). With the instrument’s AC switch
first in the ON position and then in the OFF position,
measure from a known earth ground (metal water pipe,
conduit, etc.) to all exposed metal parts of the
instrument (antennas, handle brackets, metal cabinets,
screwheads, metallic overlays, control shafts, etc.),
especially and exposed metal parts that offer an
electrical return path to the chassis.
Any current measured must not exceed 0.5mA.
Reverse the instrument power cord plug in the outlet
and repeat the test.
AC Leakage Test
Any measurements not within the limits specified
herein indicate a potential shock hazard that must be
eliminated before returning the instrument to the
customer.
(4) Insulation Resistance Test Cold Check-(1) Unplug the
power supply cord and connect a jumper wore
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 all exposed metallic cabinet parts on the
instrument, such as screwheads, antenna, control
shafts, handle brackets, etc. When an 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. If the reading is not within the limits
specified, there is the possibility of a shock hazard,
and the instrument must be re-pared and rechecked
before it is returned to the customer.
Insulation Resistance Test