Panasonic SC-AK48, Service Manual

Page: 42 / 104

S
G
D
S
G
D
S
G
D
4.7K
1 2 3 4 5
R ch
L ch
PLAYBACK
HEAD
DECK1
1
5
3
4
2
R ch
L ch
R/P HEAD
ERASE
HEAD
DECK2
1
5
3
4
2
CS1101
CS1102
TP2
TP1
R1
103
15K
C1
101
1000P
R1
183
100K
TP6
C1193
1000P
C1103
680P
C1104
0.022
R1
101
330K R1
102
100K
TP3
R1182
1
IC1102
BA7755A
R/P SELECT
V
CC
GND
C1
183
0.47
R1
189
4.7K
R1188
1K
R1195
100K
C1102
1000P
C1194
1000P
R1104
15K R1
184
100K
C1177
1000P
R1179
2.7K
R1181
3.3K
TP172
TP170
TP171
R1180
2.7K
C1
181
0.01
C1
179
0.01
C1
182
50V4.7
C1
180
0.01
D1175
MA111TX
C1178
1000P
Q1175
Q1176
R1178
1.2
C1
176
0.047
R1
177
5.6K
R1
176
4.7K
L1201
1
2
3
6
5
4 C1
185
4700P
C1
175
35V220
D1171
MA111TX
R1
173
10K
D1172
MA8047MTX
R1174
10K
C1
174
50V4.7
D1174
MA8036HTX
C1
184
1500P
R1172
330
R1
170
1K
C1
173
0.01
ERASE CURRENT
CHECK POINT
Q1173
DTC144TKA146
BIAS OSC CONT.(CrO
2
)
Q1101
2SJ498CDTA
HEAD SELECT
(REC:ON)
Q1103
2SJ498CDTA
HEAD SELECT
(PLAY:ON)
Q1104
2SJ498CDTA
HEAD SELECT
(PLAY:ON)
Q1102
2SJ498CDTA
HEAD SELECT
(REC:ON)
G
D
S
Q1175,1176
2SC2002KTA
BIAS OSC
Q1174
2SC2412KT96R
BIAS OSC CONT.
L1202 47
H
Q1179
2SC2412KT96R
SWITCHING
(BEAT PROOF)
Q1171
2SD1302STA
SWITCHING
(REC:ON)
MECHANISM CONTROL CIRCUIT
B
SCHEMATIC DIAGRAM-3
TP4
TP5
TP11 TP12
24.9V
((0.1V))
((0V))
((0V))
((0V))
0.7V
0.6V
((0V))
((0V))
((0V))
0.6V
0.9V
((0V))
((0V))
0.6V
0.6V
4.8V
((0V))
((0V))
((7.8V))
10.8V
0.1V
((0V))
((0V))
((4.4V))
4.5V
((0V))
((0V))
((0V))
4.5V
((0V))
((0V))
((0V))
((0V))
((0V))
((4.4V))
0.1V
14.6V
:TAPE PLAYBACK SIGNAL LINE
:RECORDING SIGNAL LINE
:POSITIVE VOLTAGE LINE
((14.7V))
14.3V
((0.1V))
0V
((0V))
0.1V
((14.7V))
14.3V
((0V))
0.1V
((4.8V)):CrO
2
SA-AK48
42