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COLOR TELEVISION
LC30B1
CONTENT
Safety instructions...................................................................................... 1
Instructions on adjusting and testing.............................................................. 2
Trouble shooting........................................................................................ 6
Method of software upgrading..................................................................... 8
BLOCK DIAGRAM..................................................................................... 10
IC BLOCK DIAGRAM...................................................................................
11
Wiring diagram.......................................................................................... 20
Serial NO. of parts...........................................................................................
21
Identification criteria for the bright spot and dark spot of the LCD screen............... 21
Troubleshooting guide................................................................................ 22
Exploded views......................................................................................... 26
Schematic diagram.................................................................................... 28
Attention: This service manual is only for service personnel to take reference with. Before servicing
please read the following points carefully.
Safety instructions
1. Instructions
1.1 Be sure to switch off the power supply before replacing or welding any components or
inserting/plugging in connection wire
1.2 Anti static measures to be taken (throughout the entire production process!):
a) Do not touch here and there by hand at will;
b) Be sure to use anti static electric iron;
c) It's a must for the welder to wear anti static gloves.
1.3 Please refer to the detailed list before replacing components that have special safety
requirements. Do not change the specs and type at will.
2. Points for attention in servicing of LCD
2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to use
the screen of the original model for replacement.
2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in protecting
yourself and the machine when testing the system in the course of normal operation or right after
the power is switched off. Please do not
touch the circuit or the metal part of the module that is in operation mode.
Relevant operation is possible only one minute after the power is switched off.
2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or damage
to the set.
2.4 Never operate the set or do any installation work in bad environment such as wet bathroom,
laundry, kitchen,or nearby fire source, heating equipment and devices or exposure to sunlight etc.
Otherwise bad effect will result.
2.5. If any foreign substance such as water, liquid, metal slices or other matters happens to fall into the
module, be sure to cut the power off immediately and do not move anything on the module lest it
should cause fire or electric shock due to contact with the high voltage or short circuit.
2.6. Should there be smoke, abnormal smell or sound from the module, please shut the power off at
once. Likewise, if the screen is not working after the power is on or in the course of operation, the
power must be cut off immediately and no more operation is allowed under the same condition.
2.7. Do not pull out or plug in the connection wire when the module is in operation or just after the power
is off because in this case relatively high voltage still remains in the capacitor of the driving
circuit.Please wait at least one minute before the pulling out or plugging in the connection wire.
2.8. When operating or installing LCD please don't subject the LCD components to bending, twisting or
extrusion, collision lest mishap should result.
2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it's necessary to pay
attention to anti statics. Before servicing LCD TV make sure to take anti static measure and
ensure full grounding for all the parts that have to be grounded.
1
2.10.There are lots of connection wires between parts behind the LCD screen. When servicing or
moving the set please take care not to touch or scratch them. Once they are damaged the screen
would be unable to work and no way to get it repaired.
2.11. Special care must be taken in transporting or handling it. Exquisite shock
vibration may lead to breakage of screen glass or damage to driving circuit.
Therefore it must be packed in a strong case before the transportation or
handling.
2.12. For the storage make sure to put it in a place where the environment can be controlled so as to
prevent the temperature and humidity from exceeding the limits as specified in the manual. For
prolonged storage, it is necessary to house it in an anti-moisture bag and put them altogether in
one place. The ambient conditions are tabulated as follows:
Scope for operation 0----+50 C
Temperature
Scope for storage -20----+60 C
humidity Scope for operation 20%---85%
Scope for storage 10%---90%
2.13. Display of a fixed picture for a long time may result in appearance of picture residue on the screen,
as commmonly called "ghost shadow". The extent of the residual picture varies with the maker of
LCD screen. This phenonmenon doesn't represent failure. This "ghost shadow" may remain in the
picture for a period of time (several minutes).But when operating it please avoid displaying still
picture in high brightness for a long time.
3. Points for attention during installation
3.1. The front panel of LCD screen is of glass. Wheng installing it please make sure to put it in place.
3.2. For service or instatallation it's necessary to use specified screw lest it should damage the screen.
3.3. Be sure to take anti dust measures. Any foreign substance that happens to fall down between the
screen and the glass will affect the receiving and viewing effect
3.4. When dismantling or mounting the protective partition plate that is used for anti vibration and
insulation please take care to keep it in intactness so as to avoid hidden trouble.
3.5. Be sure to protect the cabinet from damage or scratch during service, dismantling or mounting.
Description of adjustment and calibration
2.1 Adjustment and calibration equipment
Multi-meter,5515 signal generator and oscilloscope
PC set (FLASH writing programs should be installed in place first.), K7253 (VGA and YprPb signal
generator) CA210 (LCD white balancer) and DVD broadcast player.
2.2 Flow of adjustment and calibration
2
See Fig.1.
Check if memory U16 has been FLASH written.
Production of main board and TV board on the line.
Adjusting and calibrating TV board
Check the main board
Check TV board
Combined test for general assembly
Connect to central signal source, check if various TV functions (station skipping, system identification, analog
control etc) are normal and check if earphone and speaker output are normal
Input VGA signal and check if display is normal in the state of PC
and various functions (analog control, line/field center etc.
Input AV/S signal and check various functions under AV/S terminal
Input YprPb signal and check if display is normal in the state of PC
and various functions (analog control, line/field center etc
Check accessories and then packing
Fig.1 Flow process of adjustment
2.3 FLASH WRITE programs
FLASH WRITE memory N9.
2.4 Main board adjustment and calibration
a) Connect main board to infrared receiving board, turn off the power supply adapter switch and
insert the plug of power supply adapter output into main board.
b) Turn on power supply adapter, check to see indication lamp in red light and check the power
supply and confirm various power supplies as listed below:
1) Main power supply C137 anode 5 V