Service manual

CD-SW300
[1] Important service notes
BEFORE RETURNING THE AUDIO PRODUCT
(Fire & Shock Hazard)
Before returning the audio product to the user, perform
the following safety checks.
1. Inspect all lead dress to make certain that leads are
not pinched or that hardware is not lodged between
the chassis and other metal parts in the audio prod-
uct.
2. Inspect all protective devices such as insulating
materials, cabinet, terminal board, adjustment and
compartment covers or shields, mechanical insula-
tors etc.
3. To be sure that no shock hazard exists, check for
leakage current in the following manner.
* Plug the AC line cord directly into a 120 volt AC outlet.
* Using two clip leads, connect a 1.5 kohm, 10 watt
resistor paralleled by a 0.15 µF capacitor in series
with all exposed metal cabinet parts and a known
earth ground, such as conduit or electrical ground
connected to earth ground.
* Use a VTVM or VOM with 1000 ohm per volt, or
higher, sensitivity to measure the AC voltage drop
across the resistor (See diagram).
* Connect the resistor connection to all exposed metal
parts having a return path to the chassis (antenna,
metal cabinet, screw heads, knobs and control
shafts, escutcheon, etc.) and measure the AC volt-
age drop across the resistor.
All check must be repeated with the AC line cord plug
connection reversed.
Any reading of 0.3 volt RMS (this corresponds to 0.2
milliamp. AC.) or more is excessive and indicates a
potential shock hazard which must be corrected before
returning the audio product to the owner.
TO EXPOSED
METAL PARTS
CONNECT TO
KNOWN EARTH
GROUND
TEST PROBE
0.15 mF
1.5 kohms
10 W
VTVM
AC SCALE
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CHAPTER 1: GENERAL DESCRIPTION