Belson BSV-2751, Service Manual

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56, 57:left and right channels of AV IN sound;
67, 69:SIF input of TV for main and sub channels;
59:MONO input of TV for sub channel
Sound power amplifier MPS7720 is a highly efficient Type D power amplifier of mono channel input and
output. The output power can be as high as 10W under the circumstance that there is no radiator. It has
also the function of silencing abnormal sound.
b). Sub channel and SCART audio signal decoding IC(VPC3230)
The block diagram of VPC3230 is shown below:
The video signal demodulated by sub tuner TUNER202, Scart1 video signal and RGB signal as well
as Scart2 audio signal and Y/C signal, after matching with resistor separately, are fed into decoder IC
N401(VPC3230), where they are subject to D/A conversion, digital decoding. Then they are fed in digital
format (IUT656) into main processor IC N101(PanelTv-Svp). At the same time the VPC3230 VOUT
signal, after isolation, is divided into two portions. One portion is fed into video board as AV OUT for
output; the other portion is fed to N501(SDA5550) as the decoding signal for teletext. Therefore this TV
model is ready to support teletext function under TV, AV, SCART1 and SCART2.
The main pins of VPC3230 in this TV model are described as follows:
13, 14:SCL, SDA, for the control of IC operations;
4, 5, 6: RGB signal input for SCART1;
74: video signal of SCART1 or RGB compound synchronous input;
71, 72: Y/C signal input for SCART2;
73: video signal input for sub tuner;
75: AV video signal input;
70: VOUT signals of VPC3230.
c). IC(MST9883) that receives YPbPr/YcbCr and RGB
YPbPr/YcbCr and RGB signals are, after the selection and change over in N703(sn74cbt3257c), fed
into N201(MST9883), where it is subject to D/A conversion. Then they are fed in digital format to the
main processor IC N101(PanelTv-Svp).