Onkyo TX-SR403 Service Manual page 76

IC BLOCK DIAGRAM AND TERMINAL DESCRIPTIONS-18
Q1003, 1012, 1013 : LA7956 (Video switch)
BLOCK DIAGRAM
TRUTH TABLE
S2
(Pin 2)
H
L
H
L
6dB
amp
driver control
1 2 3 4 5
VIDEO A B VINI GND
OUT
S3 Vin1 Vin2 Vin3
(Pin 3) (Pin 4) (Pin 6) (Pin 8)
H ON OFF OFF
H OFF ON OFF
L OFF OFF ON
L OFF OFF OFF
video switch
(4input 1output)
6 7 8 9
VIN2 VCC VIN3 VIN4
Vin4
(Pin 9)
OFF
OFF
OFF
ON
TX-SR403/8340