Working Principle Analysis Of The Unit - Sanyo LCD-42XR8KH Service Manual

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Working principle analysis of the unit

king pr ncip p le a a ysis of the unit
The RF signal received by antenna will be sent to tuner TUN601, then IF signal will be obtained
through high amplified and mixed frequency. After pre-intermediate amplified by V608, it will be sent
to acoustic surface-wave Z605 to do IF filter and get better IF characteristics, then it will be sent to
N602 (TDA4470) to do intermediate amplification, phase-lock loop VCO and synchronous wave
detection to get the video signal TV-V; after pre-intermediate amplification IF will also be sent to
acoustic surface-wave Z604 to do filter at the same time, the it will be sent to N404 to do
intermediate amplification and output the second sound intermediate frequency signal TV-SIF.
TV-V output from TDA4470 and TV-SIF will be sent to the main IC N304(MST9E89DL)
Video and audio signals of AV/S, VGA, YPbPr will be sent to MST9E89DL too.
3 groups HDMI after PS321 selecting, their video and audio signal will be sent to MST9E89DL.
RGB of SCART1, AV, S-Y and S-C of SCART2 will also be sent to MST9E89DL, their audio
signal and YPbPr, AV/S audio signal via audio switch HEF4052BT selection to MST9E89DL.
The main IC N304(MST9E89DL) is a high performance and fully integrated IC, which can
realize HDMI interface processing, video decoding, video switch selection, A/D and D/A conversion,
interlace/de-interlace processing, modes conversion, OSD and low-voltage differential output, etc.
And it also has functions of audio selection, processing and MCU.
The video signal via MST9E89DL processing, output 4 pairs differential signal and 1 pair clock
signal for LCD panel display. TV-V from TDA4470 after video double amplifying and sent to
SCART1 as AV-OUT. AV processed by MST9E89DL after quadruple amplifying and output as
AV-OUT and SCART2 AV-OUT.
T e audio signa The audio signal via MST9E89DL processing, it will be sent to N206 (BH3547F) amplifying to gna a l v l via MST T 9E89
earphone. The audio signal will also sent to sound amplifier N203 (TPA3120-D2) amplifying to
speaker. TV-L/R processed by MST9E89DL will be sent to SCART1 for AV-OUT, at the same time,
TV-L/R and AV-L/R will output together as the audio output of AV-OUT and SCART2 AV-OUT.
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