1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or
damaged by the short circuit.
2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.
3. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.
1.1.1. Leakage Current Cold Check
1. Unplug the AC cord and connect a jumper between the two
prongs on the plug.
2. Measure the resistance value, with an ohmmeter, between
the jumpered AC plug and each exposed metallic cabinet
part on the equipment such as screwheads, connectors,
control shafts, etc. When the exposed metallic part has a
return path to the chassis, the reading should be between
1MΩand 5.2MΩ.
When the exposed metal does not have a return path to the
chassis, the reading must be
Figure 1
.
1.1.2. LEAKAGE CURRENT HOT CHECK
(See Figure 1.)
1. Plug the AC cord directly into the AC outlet. Do not use an
isolation transformer for this check.
2. Connect a 1.5kΩ, 10 watts resistor, in parallel with a 0.15µF
capacitors, between each exposed metallic part on the set
and a good earth ground such as a water pipe, as shown in
Figure 1.
3. Use an AC voltmeter, with 1000 ohms/volt or more
sensitivity, to measure the potential across the resistor.
4. Check each exposed metallic part, and measure the
voltage at each point.
5. Reverse the AC plug inthe ACoutlet and repeat each of the
above measurements.
6. The potential at any point should not exceed 0.75 volts
RMS. A leakage current tester (Simpson Model 229 or
equivalent) may be used to make the hot checks, leakage
current must not exceed 1/2 milliamp. In case a
measurement is outside of the limits specified, there is a
possibility of a shock hazard, and the equipment should be
repaired and rechecked before it is returned to the
customer.
2 Prevention of Electrostatic Discharge (ESD) to
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commo nly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and
semiconductor "chip" components. The following techniques should be used to help reduce the incidence of component damage
caused by electro static discharge (ESD).
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your
body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
which should be removed for potential shock reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static (ESD protected)" can
generate electrical charge sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically shorted together by conductive foam, alminum foil or comparable
conductive material).
7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be installed.
Caution
Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise hamless motion such as the brushing
together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD) sufficient to
damage an ES device).
3 About lead free solder (PbF)
Note: Lead is listed as (Pb) in the periodic table of elements.In the information below, Pb will refer to Lead solder, and PbF
will refer to Lead Free Solder.The Lead Free Solder used in our manufacturing process and discussed below is
(Sn+Ag+Cu).That is Tin (Sn), Silver (Ag) and Copper (Cu) although other types are available.
This model uses Pb Free solder in it.s manufacture due to environmental conservation issues. For service and repair work, we.d
suggest the use of Pb free solder as well, although Pb solder may be used.
PCBs manufactured using lead free solder will have the PbF within a leaf Symbol
Caution
•
•
Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70°F (30~40°C) higher.
• •
Please use a high temperature soldering iron and set it to 700 ± 20°F (370 ± 10°C).
•
•
Free solder will tend to splash when heated too high (about 1100°F or 600°C).
• •
If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before applying
Pbsolder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.
•
•
After applying PbF solder to double layered boards, please check the component side for excess solder which may flow onto
• •
the opposite side. (see figure below)
Suggested Pb free solder
There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder.
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used.
1. Self-check is used to check the bus of the TV and the Hex code.
2. To enter the self-check mode, pressing -/V button on the user´s controller which is on the top of the main unit, press MENU
button on the remote controller unit simultaneously, and then the display screen will appear:
3. Turn off the TVafter self-checking, and any programmed channels, channels caption data and some other user defined settings
will be erased and return to factory setting.
While pressing [VOLUME ( - )] button of the main unit, press [RECALL] button of the remote control three times within 3 seconds.
9.1.1. Key command
“1” button...Main items Selection in forward direction
“2” button...Main items Selection in reverse direction
“3” button...Sub items Selection in forward direction
“4” button...Sub items Selection in reverse direction
“VOL” button...Value of sub items change in forward direction ( + ), in reverse direction ( - )
9.1.2. Contents of adjustment mode
•
•
Value is shown as a hexadecimal number.
• •
•
•
Preset value differs depending on models.
• •
•
•
After entering the adjustment mode, take note of the value in each item before starting adjustment.
If the memory IC or DG Board is replaced, option code should be re-memorized.
If you use for other model, you should re-memorized the different option code in SERVICE mode.
1. Connect the dummy set and turn on the main power SW and check that each output voltage
of test point is within the specifications below.
2. Turn off the power supply by the remote controller and set to standby and check that each
output voltage of test point is within the specifications below.
10.2. Voltage Test Point of P-Board
Instrument NameConnectionRemarks
Digital Voltmeter
Inspection Procedure
1. Connect the dummy set and turn on the main power SW and check that each output
voltage of test point is within the specifications below.
2. Turn off the power supply by the remote controller and set to standby and check that
each output voltage of test point is within the specifications below.
10.3. Sub-Contrast Adjustment
Instrument NameRemarks
1. REMOTE TRANSMITTER
2. Ex. Signal (Sprit color bar)
Inspection ProcedureRemarks
<procedure>Modulation 87.5%
1. Receive the sprit color bar (which includes white 100% erea).
<Inspection>
1. Enter Factory adjustment mode, and select "ADJUST" mode.
Volume UP/DOWN key makes GAIN displayed under "Dynamic" to set.
Pushing the remote controller "Yellow" key for about 3 seconds, GAIN is suited to the