Service manual

CONFIDENTIAL – DO NOT COPY
Page 7-1
File No. SG-0198
Chapter 7 Theory of Circuit Operation
The operation of D-SUB 15pin route
The D-SUB 15pin is input analog signal to the MTK8202 transfer A/D converter then generates the
vertical and horizontal timing signals for display device.
The operation of HDMII CON route
The HDMI 1&2 CON is input digital signal to the PI3HDMI412FT switch output signal is process to
the MT8293. Then transfer to the MTK8202, the MTK8202 generates the vertical and horizontal
timing signals for display device.
The operation of HDTV & Component route
HDTV & Component signal is input to the MTK8202 then MTK8202 generates the vertical and
horizontal timing signals for display device.
The operation of Video 1,2,3 & S-Video route
The Video 1,2 and S-Video signal is transmission signal to the MTK8202 then MTK8202 generates
the vertical and horizontal timing signals for display device.
The operation of TV route
TV signal is processes to the tuner and output to MTK8202 then MTK8202 generates the vertical
and horizontal timing signals for display device. Audio is processes to the tuner output to SIF circuit
and output to MTK8202.Then MTK8202 process to wm8776 and output to TDA8946J transfer to
speaker
The operation of DTV route
DTV signal is processes to the tuner and transmission to MT5112 and output signal to MT5351
then MT5351 output to MT8202 generates the vertical and horizontal timing signals for display
device.
The operation of keypad
There are 7 keys to control and select the function of L42 and also has one LED to indicate the
status of operation. They are “Power, ▼▲, + -, Input, OSD”.