Brother MFC 1870MC, Руководство по обслуживанию, Страница: 36 / 217

III –
24
Main PCB Circuit Diagram 4/5
1
Connector for the NCU
2
Analog signal selectors
2
-1: Selects either input signals from the handset or those from the MODEM.
2
-2: Selects either RL1 or RL2 signals inputted from the communications network.
2
-3: Selects either sound signals (e.g., alarm beeps, key clicks and ringer sounds)
generated by the FAX engine or signals selected by
2
-2.
3
Voice switching analog selectors
3
-1: Switches between the output line and input line for monitoring. When
switched to the output line, this selector allows FAX sending operation to be
monitored; when switched to the input line, it allows received voices to be
monitored.
3
-2: Selects either voice signals inputted from the communications network or re-
corded voice signals inputted from the microphone or handset through the
MODEM.
4
Amplifier circuit for signals outputted from the MODEM.
5
Analog front end IC which processes the analog I/O signals from/to the MODEM.
6
Amplifier & shaper circuit for signals inputted from the communications network.
7
Telephone circuit for transmitting signals.
8
Speaker amplifier circuit which amplifies sounds issued from the above analog signal
selector
2
-3 and feeds them to the speaker.
-
+
C
0
1
C N T
4 0 5 3
-
+
G N D
1 2 D S P O N
C
1
0
C N T
4 0 5 3
M O V
S L
+ 5 V
M 0 V
4 0 5 3
# 1 7
+ 2 6 v
M 0 V
K I 3 2 4
# 1 8
6 7 8
1 6 4
1 1
N C U
D A R E C 1 1 C
R N G L 1 5 C
1
2
S P
P 4
B 2 B - P H
W H I T E
P 1 0
I M S A - 9 1 1 0 S - 1 8 L
# 1 8
K I 3 2 4
# 1 8
K I 3 2 4
+ 5 V
C 2
1 0 V 1 0 0
4 0 5 3
C N T
C T S L 5 3 B
C
0
1
# 1 9
# 1 9
# 1 7
R 3 7
2 2 K
R 1 8 0
C 2 2 C C 1 0 3 B
R 3 3 1 . 5 K
R 2 0
*
C 5 7
C C 1 0 4
R 2 8 4 3 K
R 1 1 5
3 3 K
R 8 9
3 . 3 K
T X O U T
R X I N B
V B I A S
3
1 6
2
M 0 V
C 9
1 6 V 1 0
R 6 3 1 K
C 4 5
C C 1 0 4
C 4 6
C C 1 0 3 B
R 6 2
1 0 0 K
C 4 8
C C 1 0 4
C 4 4
C C 2 2 1
1 5
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
# 1 5
T C 3 5 1 3 3 F
C 3
C 4
C 5
M U T E
T B U S 1 4 D
V D D
V S S
V S S
- P D
8
1
4
1 4
M O V
R S T L 1 4 A
M U T
D M K
D M T
A M K
A M T
C 3
C 4
C 5
-
+
5
7
6
2
3
4
1
# 2
N J M 3 8 6 M
C 9 2
C C 1 0 3 B
G N D
R 3 5
1 2 K
C 2 3 *
C 1 2
C C 1 0 3 B
C 2 8
C C 1 0 5 ( 2 1 2 5 C H I P )
C 5 6
C C 1 0 4
C 2 4
5 0 V
C C 1 0 4
M 0 V
+ 5 V
R 7 1
2 7 K
G N D
T L O F 1 5 C
T L O F 2 1 2 D
D A S N D 1 1 C
C 4 7
C C 1 0 4
R 7 4
1 0 0 K
R 3 4
3 0 0
1 5 B V O L 1
1 5 C V O L 3
Q 3
K R C 1 0 7 S
T L R L 5 3 A
-
+
# 1 8
I 3 2 4
R 2 6 7 5 K
C 2 5 C C 2 2 1
R 6 5
5 6 K
R 3 0
4 . 7 K
M 0 V
R 2 9 5 6 K
C 4 9
C C 1 0 2 B
R 5 1 K
C 2 1 C C 6 8 1
R 1 7
*
+ 9 V
A R E F
R L 1
-
+
# 1 8
K I 3 2 4
R 2 3 5 6 K
C 2 7 C C 1 0 4
R 2 1 1 0 K
C 2 0 C C 6 8 1
+ 2 6 V
R 2 2
1 / 1 0 W
1 K
M 0 V
R 2 4 1 5 0 K
R 1 3 0
R 1 4
4 . 7 K
R 1 6
0
M 0 V
M 0 V
A R E F
A R E F
A R E F
C 1 1
3 5 V 1 0
A R E F
R L 2
R 7 3 1 . 5 K
C I 1 5 C
D A S T 1 1 D
R D P S 1 5 C
C M L L 3 6 E
E A T 1 5 B
+ 2 6 V
+ 5 V
G N D
P L S 1 5 C
5
9
6
7
1
1 2
1 0
1 1
3
8
1 3
2
1 5
4
1 4
1 7
1 8
M 0 V
Q 5 K R C 1 0 7 S
M 0 V
1 6
T L S L 5 1 B , 5 3 B
Q 4 *
D 2
H Z S 5 C
G N D
R 1 5 1 . 5 K
R 1 9 *
D 4 *
D 7 1 S S 1 2 0
D 5 *
D 6 1 S S 1 2 0
R 4
1 K
R 3 6
1 K
1 5 E V O L 2
4 0 5 3
C M L H 1 5 C
# 1 9
C
1
0
C N T
5 3 B C T S L
C N T
4 0 5 3
T A D H 1 2 C
# 1 7
C
0
1
A D L C 1 5 B
T E L L 1 5 C
C
C N T
4 0 5 3
# 1 7
C T R L 5 1 A , 5 3 B
1
0
H A F H 1 2 C
R 2 5 2 0 0 K
R 7 2 1 . 5 K
T X S L 1 2 C
R 6
2 2 K
+ 5 V
A R E F
R 2 7
4 . 7 K
R 3 1 1 0 K
R 3 2
1 0 0 K
1 5 C R N G O
+ 5 V
M 0 V
4 0 5 3
# 1 9
6 7 8
1 6
C 2 6
C C 1 0 4
R 7 5
1 . 5 K
5 5 D H F R L
C 1 1 0
C C 1 0 4
M 0 V
O T O 1 5 C
R 1 2 1 0 0 K
M 0 V
D 8
*
5
3
9
4 3
5
9
4 1 2
1 3
1 1
1 4
1
2
1 0
1 5 1 2
1 3
1 1
1 4
1 5
1 0
2
1
8
9
1 0
1 4
1 3
1 2
7
6
5
3
2
1
C 1 9
C C 1 0 4
+ 2 6 V
D 9
1 S S 1 2 0
G N D
C 1 1 1
C C 1 0 4
C 1 1 3
1 6 V 1 0 ( 5 m m )
G N D
R 1 3 4
1 K
D 1 0
1 S S 1 2 0
8
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
1
:
-1
:
-2
:
-3
8
9
:
7
3
-1
3
-2
2
-3
4
5
6
2
-1
2
-2