Changhong Electric PT4216, Руководство по обслуживанию, Страница: 5 / 62

5
Remarks:
This drawing is for references only, please see the main assembly diagram and wire-connecting diagram for
details.
3.2
Circuit block diagram
：
PS08 chassis PDPD TV is mainly composed of regulator circuit
、
RF circuit
、
video processor circuit
、
Power Amplify
circuit
、
Analog Video circuit
、
System Control circuit and Key Control circuit, block diagram of unit circuit is below:
Power Board
AV Board
TDA8759
FL
AS
H
+6V +5VS +12
V
+32V
IF
CVBS
Analog
24bit
ITU-R656
Main Board
Panel
L V D S
GM1601
SAA7115
HDTV
Sub-
Tuner
DVI PC
UOCIII
Main
Tuner
k Panel
IR
Panel
C
on
tr
ol Signal
B G R
B G
R
Audio
Speaker
TA2024
audio amplify board
+3.3V +12V
AU
3.3 PCB assembly introduction
It is mainly composed of AV Board
、
Remote Control Receiving board
、
K Board
、
power board
、
power amplifier
board and Main Board. Herein introduct function of each PCB module
：
Number Parts Description
1 Main Board
assembly
It is the core of signal processing for PDP TV, which takes responsibility of transforming
outer signal into the uniform digital signal identified by PDP display with control of
System circuit. TV, AV and S-video signals input from AV Board are decoded by
UOCIII to output RGB signal ,A/D converted by TDA8759,output 24bit RGB digital
signal, then it is processed by GM1601/GM1501 to accomplish format convert, produce
LVDS signal displayed on the screen. In addition, signals input from VGA
、 DVI
would directly enter into GM1501 to process 、 format convert and on screen display.
2 AV Board
assembly
It is mainly composed of two tuners (main and sub tuners) 、 earphone output and some
peripheral processing circuit. The main tuner demodulates RF signal to IF signal, and
the sub tuner produces CVBS signal, all signals are sent to the main board to do
corresponding process after transfer .Earphone jack can connect earphone output directly,
and output volume can be adjusted.