Safety Precaution; Important Service Safety Precaution; Before Returning The Receiver - Sharp LC-42SB45U Service Manual

LC-42SB45U

SAFETY PRECAUTION

IMPORTANT SERVICE SAFETY PRECAUTION

■
Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and the
servicing guidelines which follow:
■ WARNING
1. For continued safety, no modification of any circuit should be
attempted.
2. Disconnect AC power before servicing.
CAUTION:
FOR CONTINUED PROTECTION AGAINST A
RISK OF FIRE REPLACE ONLY WITH SAME
TYPE FUSE.
F7000 (6.3A/250V)
■

BEFORE RETURNING THE RECEIVER

(Fire & Shock Hazard)
Before returning the receiver to the user, perform the following
safety checks:
3. 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.
4. 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.
5. 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.
• Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled
by a 0.15µF 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.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
SAFETY NOTICE
Many electrical and mechanical parts in LCD color 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 identified in this manual; electrical components having such
features are identified by " " and shaded areas in the Replacement
Parts List and Schematic Diagrams.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
• Use an AC voltmeter having with 5000 ohm per volt, or higher, sen-
sitivity or measure the AC voltage drop across the resistor.
• 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 1.05 V 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.
TO EXPOSED
METAL PARTS
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, fire or other hazards.
2
DVM
AC SCALE
1.5k ohm
10W
0.15 µF
TEST PROBE
CONNECT TO KNOWN
EARTH GROUND