KLV-19T400A, KLV-19T400G, KLV-19T400W - Sony TV Service Manual (repair manual). Page 4

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KLV-19T400A,T400G,T400W
RM-GA013
1-1. Caution Handling of LCD Panel
When installing the LCD Panel, make sure you are grounded
with a wrist band.
When installing the LCD Panel on the wall, the panel must be
secured using the 4 mounting holes on the rear cover.
1) Do not press the panel or frame edge to avoid the risk of
electric shock.
2) Do not scratch or press on the panel with any sharp
objects.
3) Do not leave the module in high temperature or in areas of
high humidity for an extended period of time.
4) Do not expose the LCD panel to direct sunlight.
5) Avoid contact with water. It may cause short circuit within
the module.
6) Disconnect the AC adapter when replacing the backlight
(CCFL) or inverter circuit. (High voltage occurs at the inverter
circuit at 650Vrms)
7) Always clean the LCD panel with a soft cloth material.
8) Use care when handling the wires or connectors of the
inverter circuit. Damaging the wires may cause a short circuit.
9) Protect the panel from ESD to avoid damaging the elec-
tronic circuit (C-MOS).
1-2. Safety Check-Out
After correcting the original service problem, perform the
following safety checks before releasing the set to the
customer:-
1) Check the area of your repair for unsoldered or poorly
soldered connections. Check the entire board surface for
solder splashes and bridges.
2) Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.
3)Check all control knobs, shields, covers, ground straps and
mounting hardware have been replaced. Be absolutely certain
you have replaced all the insulators.
4) Look for unauthorized replacement parts, particularly
transistors that were installed during a previous repair. Point
them out to the customer and recommend their replacement.
5) Look for parts which, though functioning show obvious
signs of deterioration. Point them out to the customer and
recommend their replacement.
6) Check the line cords for cracks and abrasion.
Recommend the replacement of any such line cord to the
customer.
7) Check the antenna terminals, metal trim, "metallized"
knobs, screws and all other exposed metal parts for AC
leakage. Check leakage test as described next.
1-3. Leakage Test
The AC leakage from any exposed metal part to earth
ground and from all exposed metal parts to any exposed
metal part having a return to chassis must not exceed 0.5mA
(500 microamperes). Leakage current can be measured by
any one of the three methods:-
1. A commercial leakage tester such as the SIMPSON 229 or
RCA WT-540A. Follow the manufacturers instructions to use
those instructions.
2. A battery-operated AC milliampmeter. The DATA
PRECISION 245 digital multimeter is suitable for this job.
 3. Measuring the voltage drop across a resistor by means of
a VOM or battery operated AC voltmeter. The 'limit' indication
is 0.75V so analog meters must have an accurate low voltage
scale. The SIMPSON'S 250 and SANWA SH-63TRD are
examples of passive VOMs that are suitable. Nearly all battery
operated digital multimeters that have a 2 VAC range are
suitable. (see Figure 1.)
1.5 k
0.15 
µ
F
AC
Voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
SECTION 1
SAFETY NOTES
Figure 1. AC voltmeter to check AC leakage
1-4. WARNING !
SAFETY-RELATED COMPONENT WARNING!
COMPONENTS IDENTIFIED BY SHADING AND MARK 
!
ON THE EXPLODED VIEWS ARE CRITICAL FOR SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY. CIRCUIT ADJUSTMENTS THAT ARE
CRITICAL FOR SAFE OPERATION ARE IDENTIFIED IN
THIS MANUAL. FOLLOW THESE PROCEDURES
WHENEVER CRITICAL COMPONENTS ARE REPLACED
OR IMPROPER OPERATION IS SUSPECTED.
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