Brother FAX-170 Service Manual page 41

1 2
1-1
P 1 0
B 5 B P H
A
P O W E R C R 1
O J E S H 1 2 4 D M
4
4
5 3
6
1
C 6 1
1
1 6 V
4 7
2
B
3
+ 5 + 2 6 V
G N D
1 0
3-1
1 2
1 1
3
C
3-2
T E L R L
1 4 7 A
R L 2
7 4 4 C
R L 1
6 4 4 C
3-3
T E L S L
5 2 B
5
5 5 D
C 2 6 6 8 1
D
R 2 8 5 6 K
# 4
R 2 3
B A 1 0 3 2 4 F
-
9
1 0 K
9
8
+
R 3 5 R 2 0
1 0
1 / 1 0 W
1 K
1 K
G N D
R 5 8
1 6 C P L S
3
1 K
8
3 4 E C M L L
+ 5
+ 5
E
R 5 7
* R 5 4
2 2 K
R 6 8 1 K
2 2 K
T L O F
2
C I
4
C 5 2
1 5 1 3 D T L 0 F 2
1 0 3 B
1 3 1 6 C R D P S
1 4 1 6 C E A T
G N D
1 6 1 6 C
1 7 1 2 C D A S T
1 8 1 2 B D A S N D
* P 2
F
9 1 1 0 S 1 2 L
N C U
1 2
1 Connector for the power supply PCB
1-1: CR1, recording head on/off relay
2 3-terminal regulator which eliminates unstabilized components of the +9V source to
generate stabilized 5V source.
3 Connector for the NCU
3-1: Power for the NCU
3-2: Signals to the telephone
3-3: Signals from the telephone
Analog signal selectors
4
4-1: Selects either input signals from the handset or those from the MODEM.
4-2: Selects either RL1 or RL2 signals inputted from the communications network.
4-3: Selects sound signals (e.g., alarm beeps, key clicks and ringer sounds) gener-
5 Analog signal selectors
5-1
5-2
5-3
6 Amplifier circuit for signals outputted from the MODEM
7 Analog front end IC which processes the analog I/O signals from/to the MODEM.
Amplifier & shaper circuit for signals inputted from the communications network.
8
9 Telephone circuit for transmitting signals.
3
2
+ 9 V Q 5
+ 2 6 V
7 8 0 5
1
I N
R 1 4 7
H 2 6 V
2 W C 8 9
G N D
1 K 3 5 V C 4 6
2
1 3 3 1 0 4
2 P O N
3 4 E
P 0 V
G N D
+ 5 + 2 6 V
4
C 7
1 6 V C C
5 0 V
# 4
1 0 4
V C C
C 1 1 B A 1 0 3 2 4 F
# 2
1 0 4 G N D
7 4 H C 4 0 5 3 F
G N D 1 1
8
G N D
5
G N D
5-1 C 1 6 R 1 3
+ 5 1 0 4 2 7 K
1 4 A R E F
X C O M T A D H 4 4 D
1 1
A
1 3 C
R L
1 2
1 6
4 3 C
X C H 0
C T S L 2 1 3
T X S L
1 0 V C C
5 2 B X C H 1
B 1 3 C C 1 3
# 2
C T R L 1 5
1 0 4
5 2 A Y C O M
7 4 H C 4 0 5 3 F
M C R L H A F H
2 9
G N D
4 5 B Y C H 0 1 3 C
C
M C S L
1 8
5-2
4 3 D Y C H 1
S P M N 4
4 3 D Z C O M
5
6
G N D
Z C H 0 I N H
M S S L R L
3 1 4
5-3
5 4 E Z C H 1 4 2 B X C O M
R L 2 1 2
V E E
4 1 C
X C H 0
# 3 7 R L 1 1 3
4 1 D X C H 1
S L 1 5
7 4 H C 4 0 5 3 F
4 2 D Y C O M
2
C T S L 1
5 2 B Y C H 0
1
G N D
Y C H 1
4
Z C O M
R 1 8
R N G O 5
1 6 C Z C H 0
1 0 0 K
S P M N 3
Z C H 1
4 2 C
# 2
7 4 H C 4 0 5 3 F
C 2 1
S L 4 4 C
R 1 9
1 0 4
M C S L
4 2 C
+ 2 6 V
1 . 5 K
+ 5
R 3 3
N C
Z D 2
G N D
C 1 0 5
G N D
1 6 C
1 6 C
A D L C
3
Main PCB Circuit Diagram 4/5
ated by the FAX engine, hands-free monitor signals, or voice playback signals.
Selects either signals gated by 4-2 or voice signals coming from the handset.
Selects either signals gated by 4-2 or voice playback signals.
Selects either signals gated by 4-2 or hands-free monitor signals.
4 5
+ 5
* C 1 0
3
O U T
6 8 1 B
C 7 0 * R 1 1
C 4 4
1 6 V
1 0 4
4 7
1 2 0 K
C 1 7
* R 1 4
5 2 A T R L -
1 3
1 0 0 K
1 0 3 B
+
1 2
# 4
B A 1 0 3 2 4 F
* R 2 9
D A R E C
1 2 B
C 6
N C
3 5 V
1 0
C 8
N C
M C R L
4 2 C
R 1 0 4 3 K
R 7
1 . 5 K
C 2 5
R 2 1
-
2
1
1 K
+ 1 0 4
3
R 3
4 . 7 K
# 4
8
B A 1 0 3 2 4 F
C 2 8
Z D 1
4
1 0 3 B
H Z S 5 C
4-2
G N D
1 1 C M L H
A 1 6 C
T E L L
1 0
B 1 6 C
G N D
9 R N G L
C 1 6 D
4-1
6
I N H
4-3
V E E
7
R 3 1
R 3 2
7 5 K 5 6 K
C 2 4
2 2 1
R 2 5
6
5 6 K
7
# 4
5 C 2 0
1 0 2 B
B A 1 0 3 2 4 F
A R E F
4 4 B
4 6 B
R 1 5
4 . 7 K
C 1 9 1 7 E
N C B-2
6
4 5
III – 28
6 7
* R 4 1
D 3
1 S S 1 2 0
0
* D 4 N C
9
* R 3 6
D 1
1 S S 1 2 0
0
* D 2 N C
R 4 4
T E L R L
4 1 C
1 . 5 K
C
R 4 8
Q 4
O T O B
1 4 1 6 D K T C 3 8 7 5
1 0 0 K
R 1 2
E
4 . 7 K
C 4 1
* Q 2 1 0 5
N C
D
G
G N D
G N D
S
7
A R E F
4 4 D
1 5 6 D M K
D P D M C K
R X I N A
1 6 7 D M T
D P D M D T
R X I N B
2 9 A M K
+ 5
V B I A S A P D M C K
3
1 0 A M T
T X O U T A P D M D T
C 2 3 1 1 1 C 3
V D D C 3
R 2 6 2 2 1
4
1 0 0 K 1 2 C 4
V S S 1 C 4
1 4 1 3 C 5
C 5
V S S 2
R S T L 8 5 M U T
1 5 A - P D M U T E
C 2
C 1 8
G N D
1 6 V
1 0 4
1 0
# 6
T C 3 5 1 3 3 F
:
+ 9 V
C 3
N C
6 4
G N D
V + 5
2
O U T
- I N
7
B P
S P O N R 1
1
1 3 C G A I N
C 9
3 3 K
3
8
+ I N G A I N
1 0 5
# 1
R 6
V O L 2
1 K N J M 3 8 6 M
V O L 1
1 6 C G N D
3
2
B-1
1
Q 1
K R C 1 0 7 S V O L 3
1 6 E
B-3
B
6 7
8
A
B
M O D E M T B U S
1 4 C
C
A
D
S P
C 1
L 1
1
0
1 0 V
L 4
1 0 0
2
0
P 1
B 2 B P H
G N D
E
F
8