1. VIDEO & AUDIO
1-1. FROM RF TO COMPOSITE VIDEO
When the TIMER IC (I701) selects a certain channel from antenna, CLOCK, DATA, and ENABLE of I701 signals are
inputted to the TUNER.
So, TUNER(U101) tunes up a certain channel frequency by means of PLL circuit operation and output IF (Intermediate
Frequency) signal.
This IF signal through Q103, PRE-AMP stage, and SAW FILTER is inputted to I501 #8 and #9, and it is optimized by
VCO and AFT.
As the result of these operations, COMPOSITE VIDEO SIGNAL comes from pin 51 of I501.
Because 4.5MHz sound frequency in the COMPOSITE VIDEO SIGNAL is eliminated by Z102 TRAP, only video signal
in the COMPOSITE VIDEO SIGNAL is inputted to pin 45 of I501 and 4.5MHz sound frequency is inputted to pin 48 of
I501 through Z103 FILTER.
1-2. COMPOSITE VIDEO SIGNAL
This CHASSIS includes three video signals. One is from RF(above mentioned), another is from A/V, and the third is from
PLAY MODE.
Switching IC I503 controls these three final video signal.
Once one of the two signals(TV video signal from pin 45 of I501 and A/V video signal from pin 42 of I501) is selected, the
selected signal is from pin 43 of I501 and it is inpitted to pin 1 of I503.
Another video signal from PLAY MODE is inputted to pin 4 of I503.
Also, One of the two signals(video signal from pin 1 of I503 and video signal from PLAY MODE) is selected, and the
selected signal is transmitted to pin 2 and pin 3 of I503.
Final video signal is inputted to pin 22 of I701 to detect CAPTION SIGNAL and it is also inputted to pin 38(C INPUT), pin
(Y INPUT), pin 44(SYNC INPUT).
And R-Y signal is from pin 23, G-Y signal is from pin 24, B-Y signal is from pin 22, -Y signal is from pin 22, and those
color difference signals are sent to CRT BOARD.
In CRT BOARD, those color difference signals are mixed and amplified by color difference drive method.
1-3. AUDIO SIGNAL
This CHASSIS includes three audio signals. One is from RF(above mentioned), another is from A/V, and the third is
from PLAY MODE.
Switching IC I503 also controls these three audio signal.
TV Audio signal from pin 3 of I501 is inputted to pin 8 of I503.
A/V audio signal from A/V JACK is inputted to pin 11 of I503 and outputted to pin 9, pin 10.
So, that audio signal is inputted to pin 16 of IU01.
Audio signal from PLAY MODE is inputted to pin 2 of IU01.
One of the two audio signals(audio signal from PLAY MODE, audio signal from A/V mode) is selected and outputted to
pin 22 of IU01 and inputted to pin 1 of I501.
Audio signal to be inputted pin 1 of I501 and controlled volume is outputted to pin 4 of I501.
That audio signal is inputted to pin 3 of I601(SOUND AMP), and amplified by I601 and outputted to pin 5 of I601.
Finally that audio signal goes into SPEAKER.
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SIGNAL FLOW
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