Sound/Av3 Control (Schematic Sheet 2) - Hitachi 32PD3000 Service Manual

Pin
Description
No.
14 Input TV signal input
16 Input CVBS - SCT100-TOP (AV2) input
18 Input CVBS - SCT100-BOTTOM (AV3) input
20 Input CVBS/Y - SCT101 (AV1) input
21 Input C - SCT101 (AV1) input
23 Input CVBS/Y - front AV (FRONT) input
24 Input C - front AV (FRONT) input
28 Input Y - from COMB filter
29 Input C - from COMB filter
15 Input SCT100-TOP (AV2) pin 8 detection
17 Control SCT100-BOTTOM (AV3) pin 8 detection
- Control SCT101 (AV1) pin 8 detection is done by micro IC704 pin 28
26 Output Go to COMB filter and phono video output
32 Output Go to micro for TELETEXT decoding
34 Output Go to SCT100-TOP (AV2) and SCT100-BOTTOM (AV3) as monitor video output
20 Output L/L' switch for SAW filter in/out at SAW101
22 Control Micro sw to switch SVHS or CVBS for front AV input

Sound/AV3 Control (Schematic Sheet 2)

4.3.
NICAM/A2 Decoder and Sound Control
4.3.1.
QSS signal is coming from IC100 to pin 58 through amplifier Q308/Q307. The signal level at pin 58
should be 0.1~0.8V
Sound output L/R at pin 28 and 29 are connected through amplifier Q310/Q312 for L and Q309/Q311
for R to adjust 500mVrms at PL700 pin 4 and 6 in the condition of AV sound input 500mVrms, FM
modulation 54%.
Sound output L/R at pin 28 and 29 are also connected through IC300 TDA7433 and IC303 to
headphone. Monitor sound L/R outputs for speaker are connected headphone and phone out. IC300
contributes separate volume control.
Headphone sound L/R controlled its level by IC300 are amplified.
AV3000 AVC Unit Service Manual
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