LC-32GA5E (serv.man5). (3) Important Service Safety Precaution - Sharp TV Service Manual (repair manual)

1. For continued safety, no modification of any circuit should be attempted.
2. Disconnect AC power before servicing.

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 110~240 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 50k 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.

TO EXPOSED
METAL PARTS

CONNECT TO
KNOWN EARTH
GROUND

DVM

AC SCALE

50k ohm

10W

0.15 F

TEST PROBE

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 “   “ 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 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.

“ALL  PWB” of this model employs lead-free solder. The LF symbol indicates lead-free solder, and is attached on the
PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder.
Example:

When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional lead
wire solder may cause damage or accident due to cracks.
As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40°C, we recommend you to
use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldering bit, contact our
service station or service branch in your area.

As the melting point of lead-free solder (Sn-Ag-Cu) is about 220°C which is higher than the conventional lead solder by
40°C, and as it has poor solder wettability, you may be apt to keep the soldering bit in contact with the PWB for extended
period of time. However, Since the land may be peeled off or the maximum heat-resistance temperature of parts may be
exceeded, remove the bit from the PWB as soon as you confirm the steady soldering condition.
Lead-free solder contains more tin, and the end of the soldering bit may be easily corroded. Make sure to turn on and
off the power of the bit as required.
If a different type of solder stays on the tip of the soldering bit, it is alloyed with lead-free solder. Clean the bit after every
use of it.
When the tip of the soldering bit is blackened during use, file it with steel wool or fine sandpaper.

Be careful when replacing parts with polarity indication on the PWB silk.

Lead-free wire solder for servicing.

Indicates lead-free solder of tin, silver and copper.

g

Part No.

★

Description

Code

ZHNDAi123250E

J

φ

0.3mm

250g(1roll)

BL

ZHNDAi126500E

J

φ

0.6mm

500g(1roll)

BK

ZHNDAi12801KE

J

φ

1.0mm

1kg(1roll)

BM