Panasonic TH-42PX20U-P Service Manual page 385

PA
Speaker out,Regulator Board
Q2310
TO
PA6
DG6
IC2401
SOUND CTRL
1 1 L IN
L IN
IC2402
3 2 R IN ACTIVE FL
R IN
200Hz
L OUT 25
LPF
13 30
SCL
SCL1
14 31
SDA
SDA1
IC2403
R OUT 24
7 10
SUB MONO HP IN ACTIVE FL
400Hz
HPF
19
POFF DEF
STB5V
Q2304
18
RESET
Q2303
STB5V
Q2308
Q2311
20
MAIN DEF
16 A MUTE
SP MUTE
Q2309
TO P7
PA7
1
+15Vs +15Vs
2
+15Vs
+15Vs
TH-42PX20U-P
PA and G-BOARD BLOCK Diagram
IC2301 TO
WOOFER
HP AMP(L)
PA1
IN OUT+
11 16 4
BEEP OUT-
12 17 5
1
AMP
4
STB SW
2
HP IN HP OUT
Q2312
1 28
IC2302
HP AMP(R)
PA9
IN OUT+
11 16
4
BEEP OUT-
12 17
6
AMP
4
STB SW
HP IN HP OUT
1 28
TO
IC2305
SPEAKER
SP AMP(L)
PA3
IN OUT+
11 16 3
BEEP
OUT-
12 17 4
1
AMP
4
STB SW
2
IC2306
SP AMP(R)
IN OUT+
11 16
BEEP OUT-
12 17
AMP
4
STB SW
MUTE
9V
STB5V
Q2305
Q2306
PA22
2 9 8 1
TO PF10
NR21V
W L+
NR21V
STB5V
W L-
W R+
NR14V
W R-
JK3714
G5
VIDEO3
HP L
4
IN
L
HP R
6
R
HP
OUT
TO
S3707
G7
DG7
CH.UP
S3706
V 16
V
CH.DN
R 19 R
S3705
L 18
L
VOL.UP
S3704
SW 9
VOL.DN
C 14 C
S3703
Y 12 Y
TV/VTR
KEYSCAN1 5
SP L+
KEYSCAN2 2
SP L-
S3702
V-pulse 28
SP R+ ASPECT
15
26
H-pulse
SP R-
5
10
TO 14
G18 JK3709
4
DG18
9
13 PC IN
R
5
3
VGA
8
G 12
3 (fH=31.5kHz)
2
7
B 11
1
1
6
Front Input Board
PA4
10 11 4 5 6 7 7 6 5 4 11 10 1 8 9 2
IC7501
PA10
AVR 9V
1
SUB 9V
2 1 2
7 STB5V IC2304
AVR 9V
SUB 9V2
5 1 3 9V
IC7502
AVR 9V2
IC2102
AVR 12V 1 2
1 2 12V
IC7503
AVR 5V
1 2
IC7504
21V
AVR 4.2V
1 2
5
IC7505
14V
AVR 2.5V
1 2
G
PA8 19 18 6 3 4 17 8 9 10 11 12 14 15 PA23 1 2
TO
PA2
DG2
3
SUB 9V
IC7581
5
SUB 9V
TUNER 30V
Q7582
3 5 1
BT 30V
Q7581 4
Q7501
15
MAIN 9V
21
SUB 9V2
23
SUB 9V2
Q7502
32
TV ON
7
SUB 5V
19
SUB 5V
11
MAIN 4.2V
13
MAIN 4.2V
Q7509 Q7510
25
MAIN 2.5V
27
MAIN 2.5V
Q7543 Q7504
36
AC ON/OFF
MAIN4.2V
Q7541
33
SOS
Q7542
TO D12
PA12
TXD
1
TXD
RXD
3
RXD
STB5V
5
STB5V
12V
7
12V
PA21
12V
12V
7
STB5V
STB5V
5
RXD
RXD
3
TXD
TXD
1
4 5 6 7 8 PA24 4 7 3 1 5
TH-42PX20U-P
PA and G-BOARD BLOCK Diagram