Panasonic TH-42PX20U-P Service Manual page 209

14.12. PA and G-Board Block Diagram
PA
Speaker out,Regulator Board
TO
PA6
DG6
IC2401
SOUND CTRL
1 1 L IN
L IN
3 2 R IN
R IN
13 30
SCL
SCL1
14 31
SDA
SDA1
7 10
HP IN
SUB MONO
19
POFF DEF
STB5V
Q2304
18
RESET
Q2303
Q2308
20
MAIN DEF
16
SP MUTE
TO P7
PA7
1
+15Vs +15Vs
2 +15Vs
+15Vs
TH-42PX20U-P
PA and G-BOARD BLOCK Diagram
Q2310
IC2402
ACTIVE FL
200Hz
L OUT 25
LPF
IC2403
R OUT 24
ACTIVE FL
400Hz
HPF
STB5V
Q2311
A MUTE
Q2309
IC2301
HP AMP(L)
IN
11
BEEP
12
AMP
4
STB SW
HP IN HP OUT
Q2312
1
IC2302
HP AMP(R)
IN
11
BEEP
12
AMP
4
STB SW
HP IN HP OUT
1
IC2305
SP AMP(L)
IN
11
BEEP
12
AMP
4
STB SW
IC2306
SP AMP(R)
IN
11
BEEP
12
AMP
4
STB SW
MUTE
9V
STB5V
Q2305
Q2306
TO
WOOFER
PA1
OUT+
16 4 W L+
OUT-
17 5 W L-
1 W R+
2
W R-
28
PA9
OUT+
HP L
16
4
OUT-
HP R
17
6
28
TO
SPEAKER
PA3
OUT+
16 3
SP L+
OUT-
17 4
SP L-
1
SP R+
2
SP R-
OUT+
16
OUT-
17
PA22 2 9 8 1 10 11 4
G5
4
L
6
R
TO
G7
DG7
V 16
19
R
L 18
SW 9
C 14
C
Y 12 Y
KEYSCAN1 5
KEYSCAN2 2
V-pulse 28
15
26
H-pulse
5
10
TO
14
G18
4
DG18
9
13
R
5
3
8
12
G
3
2
7
11
B
1
1
6
PA4
5 6 7 7 6 5 4
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