LC-60LE841E - Sharp TV Service Manual (repair manual). Page 2

LC-60/70LE740E/RU,741E/S,743E,60LE840E/RU,841E/S,843E,80LE645E/RU,646E/S,648E (1st Edition)

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LC60LE740E

Service Manual

 

„ WARNING

1. For  continued safety ,  no modifica tion  of any circuit sho uld  be

attempted.

2. Disconnect AC power before servicing.

„ BEFORE RETURNING THE RECEIVER 
(Fire & Shock Hazard)

3. Inspect all lead dress to make  certain that leads  are not pinched,

and  check  that har dware  is not lo dged  between  the chassis and

other metal parts in the receiver.

4. Inspect all protective devices su ch as non-metallic control knobs,

insulation  materials,  cabinet  backs,  adjustment  and comp artment

covers or shields, isolation resistor-capacitor networks, mechanical

insulators, etc.

5. To be sure that no shock hazard exists, check for leakage cur rent

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 paral-

leled by a 0.15µF capacitor in series with all exposed metal cabinet

parts and a known earth ground, such as electrical conduit or elec-

trical ground connected to an earth ground.

• 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.

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

Many  electrical  and  mechanical p arts  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.

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.

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

FOR CONTINUED PROTECTION AGAINST A

RISK OF FIRE REPLACE ONLY WITH SAME

TYPE FUSE.

F7001 (5A/250V)

DVM

AC SCALE

1.5k ohm

10W

TO EXPOSED

METAL PARTS

CONNECT TO

KNOWN EARTH

GROUND

0.15

µF

TEST PROBE