Important Service Notes (For U.s.a. Only) - Sharp HT-CN300 Service Manual

HT-CN300

IMPORTANT SERVICE NOTES (FOR U.S.A. ONLY)

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 product.
2. Inspect all protective devices such as insulating materials,
cabinet, terminal board, adjustment and compartment covers
or shields, mechanical insulators 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 voltage drop across the resistor.
TO EXPOSED
METAL PARTS
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.
– 2 –
VTVM
AC SCALE
1.5 kohms
10 W
0.15 µF
TEST PROBE
CONNECT TO
KNOWN EARTH
GROUND