Sanyo LCD-22XR7SN, Service Manual

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Working principle analysis of the unit
The RF signal received by antenna will be sent to tuner TUNER101, then IF signal will be
obtained through high amplifier and mixed frequency, through pre-intermediate amplified by V101,
then it will be sent to acoustic surface-wave Z102 to do IF filter and get better IF characteristics,
then it will be sent to N101 (R2S10401) to do intermediate amplification, phase-locked loop VCO
and synchronous wave detection to get composite video signal TV-VIDEO; after pre-intermediate
amplification IF will also be sent to acoustic surface-wave Z101 to do filter at the same time, then it
will be sent to N101 to do intermediate amplification and output the second sound intermediate
frequency signal (TV-SIF).
The TV-VIDEO signal output from R2S10401 together with TV-SIF will be sent to main IC NS2
(MST9U19A). Video signals of AV1, AV2, S-VIDEO and YPbPr will be sent to MST9U19A, and
their audio signals will also be sent to MST9U19A (AV1 and YPbPr share one group of audio ports,
AV2 and S-VIDEO share one group of audio ports). The video and audio signals of VGA and HDMI
will be sent to MST9U19A, too.
The main IC NS2(MST9U19A) is a high performance and fully integrated IC, which can realize
HDMI processing, video demodulating, video switch selection, A/D and D/A conversion,
interlace/de-interlace processing, modes conversion, OSD and low-voltage differential output, ect.
And it also has functions of audio selection, processing and MCU.
The video signal via MST9U19A processing, output 4 pairs differential signal and 1 pair clock
signal for PDP panel display. AV1, AV2, S-VIDEO and video signal of TV via selecting and
processing, then output AV-OUT signal to double amplifying, then it will be sent to AV-OUT.
Audio signal via MST9U19A processing, one way will be sent to sound amplifier NV4
(R2S15102) amplifying to speaker. The other way via NV3(LM358) amplifying, then sent to AV-OUT.
Wor W king pr ncip ple a a ysis of the unit
A dio signnal vvia ia MST T9U U19A 44 V4 N er plifi mp a nd oun to nt en s be ll wi wi y wa on g, o