Sharp AQUOS LC-19D45U, Руководство по обслуживанию, Страница: 2 / 126

2
LC-19SK25U/U-W
LC-19SB25U/U-W
LC-19SB15U
LC-19D45U
A V
C AU T I O N :
F O R C O N T I N U E D
PROTECTION AGAINST A RISK OF
FIRE REPLACE ONLY WITH SAME
TYPE F7502 (2.5A, 250V) FUSE.
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 identified in this manual; electrical
components having such features are identified by "
! "
IMPORTANT SERVICE SAFETY PRECAUTION
Service work should be performed only by qualified service technicians who are thor-
oughly familiar with all safety checks and the servicing guidelines which follow:
and shaded areas in the Replacement Parts Lists and
Schematic Diagrams .
For continued protection, replacement parts must be
identical to those used in the original circuit.
The use of 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.
WARNING
1. For continued safety, no modification 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 120 volt AC outlet,
and connect the DC power cable into the receiver's
DC jack. (Do not use an isolation transformer for this
test).
•
Using two clip leads, connect a 1.5k ohm, 10 watt
resistor paralleled by a 0.15µF 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.
•
Use an AC voltmeter having with 5000 ohm per volt,
or higher, sensitivity 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 0.75V peak (this corresponds to 0.5
mA. peak AC.) or more is excessive and indicates
a potential shock hazard which must be corrected
before returning the monitor to the owner.
DVM
AC SCALE
1.5k ohm
10W
TO EXPOSED
METAL PARTS
CONNECT TO
KNOWN EARTH
GROUND
0.15 µF
TEST PROBE