Sanyo PDP-42XR7K Service Manual

Contents

6Working principle analysis of the unitThe RF signal received by antenna will be sent to tuner TUN601, then IF signal will be obtainedthrough high amplified and mixed frequency. After pre-intermediate amplified by V608, it will be sentto acoustic surface-wave Z605 to do IF filter and get better IF characteristics, then it will be sent toN602 (TDA4470) to do intermediate amplification, phase-lock loop VCO and synchronous wavedetection to get the video signal TV-V; after pre-intermediate amplification IF will also be sent toacoustic surface-wave Z604 to do filter at the same time, the it will be sent to N404 to dointermediate 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 audiosignal 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 canrealize 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 clocksignal for PDP panel display. TV-V from TDA4470 after video double amplifying and sent toSCART1 as AV-OUT. AV processed by MST9E89DL after quadruple amplifying and output asAV-OUT and SCART2 AV-OUT.The audio signal via MST9E89DL processing, it will be sent to N206 (BH3547F) amplifying toearphone. The audio signal will also sent to sound amplifier N203 (TPA3120-D2) amplifying tospeaker. 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.