Sharp LC-24LE240E Operation, Service Manual

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4
LC-24LE240
TO EXPOSED
METAL PARTS
CONNECT TO
KNOWN EARTH
GROUND
DVM
AC SCALE
1.5k ohm
10W
0.15 μ F
TEST PROBE
SAFETY NOTICE
Many electrical and mechanical parts in LCD television have special safety-related characteristics.
These characteristics are often not evident from visual inspection, nor can protection afforded by them be necessarily
increased by using replacement components rated for higher voltage, wattage, etc.
Replacement parts which have these special safety characteristics are identi
fi ed in this manual; electrical components
having such features are identi fi ed by “ “.
For continued protection, replacement parts must be identical to those used in the original circuit.
The use of a substitute replacement parts which do not have the same safety characteristics as the factory recommended
replacement parts shown in this service manual, may create shock,
fi re or other hazards.
IMPORTANT SERVICE SAFETY PRECAUTION
Service work should be performed only by quali fi ed service technicians who are thoroughly familiar with all
safety checks and the servicing guidelines which follow:
WARNING
1. For continued safety, no modi fi cation of any circuit should be attempted.
2. Disconnect AC power before servicing.
BEFORE RETURNING THE RECEIVER (Fire & Shock Hazard)
Before returning the receiver to the user, perform the following safety checks:
1. Inspect all lead dress to make certain that leads are not pinched, and check that hardware is not lodged between the
chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulation materials, cabinet backs, adjustment and
compartment covers or shields, isolation resistor-capacitor networks, mechanical insulators, etc.
3. To be sure that no shock hazard exists, check for leakage current in the following manner.
•

Plug the AC cord directly into a 220~240 volt AC outlet. (Do not use an isolation transformer for this test).
•Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled by a 0.15 μ F capacitor in series with all exposed metal
cabinet parts and a known earth ground, such as electrical conduit or electrical ground connected to an earth ground.
•A true RMS reading multimeter should be used for this test, especially where the equipment uses a switch mode
power supply which may result in very non-sinusoidal leakage current.
•Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal cabinet,
screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor.
All checks must be repeated with the AC cord plug connection reversed. (If necessary, a nonpolarized adaptor plug must
be used only for the purpose of completing these checks.)
Any reading of 1.05V peak (this corresponds to 0.7 mA. peak AC.) or more is excessive and indicates a potential shock
hazard which must be corrected before returning the monitor to the owner.
!
CAUTION : FOR CONTINUED PROTECTION AGAINST A RISK OF
FIRE REPLACE ONLY WITH SAME TYPE
F700,
F701 (T 3.15A L250V)