Brother FAX-270MC, Service Manual

Page: 43 / 220

III – 30
+ 5
# 1 0
B A 1 0 3 5 8 F
X C O M
1 5
A
B
1 1
1 0
9
# 5
T C 3 5 1 3 3 F
C
1 4 C
I N H
6
A M U T
D M K
A D M D
A M K
A A M D
C 0
C 1
C 2
-
+
-
+
# 1 0
B A 1 0 3 5 8 F
R 7 1
C 6 0
1 0 2 B
1
2
P 1 5
B 2 B P H
1 7 E
1 3 C
1 7 D
1 7 D
1 1
8
2
1
6
4
3
5
7
9
C L R S T
1 0
1 3 C
P 1 4
B 1 1 B P H
7
6
5
3
2
1
R X I N A
A P D M D T
D P D M C K
D P D M D T
A P D M C K
5
6
7
9
1 0
1 1
1 2
1 3
C 3
C 4
C 5
M U T E
X C H 0
X C H 1
Y C O M
Y C H 0
Y C H 1
Z C O M
Z C H 0
Z C H 1
# 1 1
7 4 H C 4 0 5 3 F
V E E
C0
V
GN
D
4 2 C
4 5 A
C7
5
104
+9
V
C T R L
* R 8 4
N C T R L
0
* R 8 9
* R 8 8
4 . 7 K
* R 8 7
1 0 0 K * R 8 0
1 0 0 K
* R 8 3
1 0 0 K
* R 8 6
N C
4 2 C
4 1 D
4 4 C
C T S L 2
T E L S L
C T S L 1
1 4
1 2
1 3
1 5
2
1
4
5
3
7
G N D
C L S E L
C T S E L
1 6 C
1 6 D
R
100
100K
R9
9
100K
G N D
1 7 D
C L C I
C L T X S
C L C K
C L B S Y
C L R X S
C
111
101
C
112
101
C
113
101
C
114
101
C
115
101
C
116
101
G N D C 0 V
M O D E M T B U S
R X I N B
V B I A S
T X O U T
V D D
V S S 1
V S S 2
- P D
1 6
2
3
1
4
1 4
8
+ 5
C 1 2
1 0 4
R S T L
1 4 A
G N D
C 2 2
2 2 0 P
C 1 4
1 0 4
R 2 4
1 0 0 K
C 5
1 6 V
1 0
G N D
R 6 7
5 6 K
5 6 K
C 6 3
N C
R 7 3
7 5 K
C 5 5
2 2 0 P
R 6 4
4 . 7 K
G N D
R 5 9
2 K
M S S L
4 2 C
C 5 4
1 0 4
* R 7 5
N C
T E L S L
5 2 B
# 1 1
7 4 H C 4 0 5 3 F
C 6 6
1 0 4
1
2
R 7 0
4 . 7 K
G N D
C 5 9
1 8 2 B
R 7 2
2 2 0 K
R 7 9
2 2 0 K
C 6 9
1 8 2 B
R 7 7
1 0 K
R 8 1
1 0 K
C 6 5
1 0 4
C 7 3
1 0 4
R 9 0
1 . 5 K
R 9 1
1 . 5 K
G N D
+ 5
* R 1 3 8
8
G N D
V C C
G N D
1 6
# 1 0
B A 1 0 3 5 8 F
C 5 8
1 0 4
+ 5
4
G N D
V C C
G N D
8
0
1 2 3 4 5 6 7 8
2 1 3 4 5 6 7 8
A
B
C
D
E
F
A
B
C
D
E
F
Not mounted.
1
2 3
4
Main PCB Circuit Diagram 5/5
1 Microphone connector
2
Amplifier and shaper circuit for signals inputted from the microphone.
3
Analog front end IC which processes the analog I/O signals from/to the MODEM.
4 Amplifier circuit for signals outputted from the MODEM.