BenQ SE2241, Product Service Manual

Page: 66 / 88

3
Level 3 - Component Repair to Circuit Boards
Theory of Circuit Operation
Video:
The MSD2379AG is a high performance and fully integrated IC for multi-function LCD monitor/TV
with resolutions up to HD(1920x1080).It is configured with an integrated triple-ADC/PLL, an
integrated Note DVI/HDCP/HDMI receiver , a multi-standard TV video and audio decoder, a video
de-interlacer, a scaling engine, the MStarACE-3 color engine, an on-screen display controller, an 8-bit
MCU and a built-in output panel interface.With external frame buffer, 3-D video decoding and
processing are fulfilled for high-quality TV applications.To further reduce system costs, the The
MSD2379AG comprises an MPEG-2 transport processor with advanced section filtering capability,
an MPEG-2 (MP@ML profile) video decoder, an MPEG layer I and II digital audio decoder with
analog audio outputs that are designed to support DVB SDTV programs while handling conditional
access.
Audio:
The YDA148(D-510) is high-efficiency digital audio power amplifier IC with output of 2 x 3w to
8hm load with 12V supply voltage. YDA148 features Power Limit Function, Non-clip Function, and
DRC (Dynamic Range Control) Function that were eveloped by Yamaha original digital amplifier
technology. YDA148 has overcurrent protection function for speaker output terminals, high
temperature protection function, and lowsupply voltage malfunction prevention function.
TUNER FEATURES:
INTERMEDIATE FREQUENCIES
SYSTEM
FREQUENCY (MHz)
[1]
B/G I D/K L L’
Picture carrier 38.90 38.90 38.90 38.90 33.9
Color 34.47 34.47 34.47 34.47 38.33
Sound 1 33.40 32.90 32.40 32.40 40.40
Digital IF Center Frequency
(Bandwidth: 7MHz / 8MHz)
36.1667
CHANNEL COVERAGE
BAND FREQUENCY(MHz)
Low band 45.25 to 147.00 MHz
Mid band 147.25 to 431.00MHz
High band 431.25 to 863.25 MHz
PINNING