XOCECO LC-52R36, Service Manual

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6
Working principle analysis of the unit
The RF1 via integrative tuner TUNER1 after, the FBAS VIDEO1 and SIF is generated. The RF2 via
integrative tuner TUNER2 after, the FBAS VIDEO2 and AUDIO is generated. Video signal and
audio signal of VIDEO1,VIDEO2,AV1/SVHS1,AV2,AV3 and audio signal of VGA and so on, its sent
NA3 (CXA2089Q) to switch selection. The output video signal of main picture (Y/V, C) sent N7
(TVP5160) to decode. The signal via N7 decode after, it sent 8-bit ITU-R656 format signal to N10
(FLI2310) non-interlaced processing. It sent 24bit YUV signal to main processing control chip
N15(GM1501/1601).
The sub-picture video signal via CXA2089Q select after, it sent N8 (TVP5147) to decode. The signal
via N8 decode after, it sent 8-bit ITU-R656 format signal to N15 (GM1501/1601). Therein, the signal
of TUNER2 is sub-picture only.
The main-picture video signal from CXA2089Q is sent to decoder and also AV OUTPUT.
USB signal via A/V decoder AML278 to output RGB and digital audio signal, the audio signal via
CS4334 D/A convert then output L/R-USB.
Two ways YPBPR signal via HDTV switch NA1(PI5V330W) selection after, it sent to HDTV switch
device NA15(PI5V330W) switch selection together with USB signal, then sent RGB switch
N4(PI5V330W) select with RGB from VGA port of PC , then it sent to GM1501/1601.
Another two ways HDMI via HDMI switch (FSHDMI04) selecting after, it sent to HDMI receiver
N34(MST3383MB), then output RGB signal of 24bit to GM1501/1601.
They sent to GM1501/1601 picture processing, therein YPBYP or RGB to A/D conversion after, it
and other two signals are switched selection and digital display processing, it include OSD, GAMMA
correction, brightness and contrast processing, then LVDS conversion to signal acceptable for LCD
panel, namely four pairs of differential signal and one pair of clock signal, then it is sent to image
enhancer PW9702 to improve the image, and then to LCD panel for picture display.
The SIF of tuner output signal to audio processing NA4(MSP3420),The audio of main-picture and
sub-picture via switch conversion CXA2089Q to MSP3410; the audio of two YPBPR and USB
processed by AML3278 via switch conversion NA2(HEF4052) to MSP3410, the HDMI via
MST3383MB decode to audio, it audio via N26(CS4334) D/A conversion to MSP3410 too.
The stereo of the SIF with other four ways audio switch conversion selection to volume control and
audio processing. One way output right/left channel audio of main-picture, the signal sent SRS
processing NA5 (M62494) to SRS sound stereo processing. It via sound amplifier NA20, NA21
(TPA3001D1) to speaker; one way output right/left channel audio of sub-picture, it sent to earphone,
another way is AV OUT R/L output.
The work of whole unit is controlled by MCU, which includes GM1501/1601.