Hitachi 46W500 Training page 55

DP-3X MAIN / SUB AUDIO SELECT CIRCUIT DIAGRAM EXPLANATION
(See Main/Sub Audio Select Circuit Diagram for details)
I301 responsibility is to route either the Main Tuner's Audio or the Sub Tuner's Audio to the Selector IC, IV01.
This is possible while in the Split Screen mode for PinP. By pressing the Swap button in this mode, the audio is
switched between Main and PinP Audio.
The following describes the Left and Right audio path to IV01 Selector IC, pin 47 Right and pin 48 Left
Main Tuner U301 (Left Total, Right Total):
From pin 27 Right and pin 26 Left.
Through C099 Right, C098 Left.
To I301 pin 1 Right, pin 13 Left.
Sub Tuner 302 (PinP Tuner):
From pin 27 mono audio.
To Q050.
Through C086.
To I301 pin 2 Right, pin 12 Left.
I301 Main/Sub Selector IC.
The Audio inputs are selected by the control lines at pins 10 and 11. These pins are controlled by the output from
the Microprocessor I001 pin 72 through inverter Q033.
•
Pins 10 and 11 High = Main Tuner.
•
Pins 10 and 11 Low = Sub (PinP) Tuner.
I302 outputs the selected audio on the following pins, 15 for Right and 14 for Left. Through the PST2 connector
pin 47 Right and 48 Left to the A/V Selector IC IV01 pin 64 Right and pin 62 Left.
(See Audio (Main/Terminal) Signal Path Circuit Diagram for details related to the continuation of the Audio sig-
nal flow)
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