akira LCT-20CH01ST, Service Manual

Page: 26 / 97

Model No.:LCT-20CH01ST.doc
Version:1.0 26
3. Introduction of printed board module
AKIRA LCD TV with LS01 is made up of power board, side AV board, remote control reception board, key
board, and mainboard. The table below is the introduction of the function of all printed board modules.
No.
Module
Designation
Function Description
1
Main
Board
Module
Main Board module is the chassis part of LCD TV signal processing. Under the control of
the system control circuit, It undertakes the task of converting the external input signal into
the unified digital signal that the LCD screen could identify. Mainboard controls the whole
machine through MCU bus, decode VIDEO signal, controls the image analog quantity
(brightness, contrast, chroma, hue, definition etc), adjusts white balance, generates OSD,
de-interlaces signal, converts signal frequency, and finishes signal A/D and D/A conversion,
video enhancement, LVDS signal coding and output; it has Scart interface, “S” terminal, AV
terminal, Ypbpr, HDMI and PC interface, Tuner input, sound demodulation, sound effect
treatment, sound power amplifier, and online upgrade of program.
2
Remote
Reception
Board
Module
The remote reception board module is constituted by an indicator-light and a remote
reception-head. Customer could manipulate the LCD TV by using remote controller very
conveniently. By the color of the indicator light, the operation mode of the LCD TV could be
judged (red is standby, green is power on).
3
Built-in
Power
Board
Module
Convert the 100V
～
240V AC into DC, output have +24v, +12V, +5V, and the +5V_stb in
standby state.
4
Keyboard
Module
Keyboard module has 7 function keys (program increase/decrease, volume
increase/decrease, AV/TV switch, menu key, on/standby control), customer could use the
key of the machine to manipulate the LCD TV.
5
LCD screen
module
LCD screen has built-in inverter that convert DC into high voltage AC signal to ignite the
backlight CCFL (Cold Cathode Fluorescent Light); the LCD screen process the video signal
from signal board and reappear.
6 Side AV board Side AV board is used for earphone output.