Yamaha GX-700, Руководство по обслуживанию

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A B C D E F G H
1
2
3
4
5
6
I J K L M N
7
8
9
10
GX-700/GX-700VCD
■
SCHEMATIC DIAGRAM (GX-700 INPUT)
The voltages are measured by LH tape at PLAY mode (no-signal condition)
Only the voitages (
) are at REC mode.
●
DOLBY NR OFF
* All voltage are measured with a 10M
Ω
/V DC electric volt meter.
* Components having special characteristics are marked
Z
and
must be replaced with parts having specifications equal to those
originally installed.
* Schematic diagram is subject to change without notice.
IC3, 4 : TC4052BF
Dual 4 Channel Analog Multiplexers/Demultiplexers
INHIBIT
0
0
0
0
1
B
0
0
1
1
X A
0
1
0
1
X
0x, 0y
1x, 1y
2x, 2y
3x, 3y
NONE
IC7 : LC75393E
Electronic Volume Control
CCB BUS INTERFACE
D LATCHES
RSBC2
RHP1
RHP2
RRECOUT10
RRECIN10
RRECOUT1
RCOM1
RH
RF2C1
RF2C2
RF2C3
RF1C1
RF1C2
RF1C3
RTIN
RSVROUT
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
LSBC2
LHP1
LHP2
LRECOUT10
LRECIN10
LRECOUT1
LCOM1
LH
LF2C1
LF2C2
LF2C3
LF1C1
LF1C2
LF1C3
LTIN
LSVROUT
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
RSBC1 RCOM2 R1dBOUT R10dBIN R10dBOUT RVSS CE DI CL DVSS LVSS L10dBOUT L10dBIN L1dBOUT LCOM2 LSBC1
49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
VCOFF VCON
DIRECT PASS DIRECT PASS
VCOFF
VCON
RSVRIN
RVCOUT
VDD
RVref1 RVref2
RIN
VC4 VC3 VC2 VC1
LIN
LVref2 LVref1 MICIN
LVCOUT
LSVRIN
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
IC5 :
µ
PD4066BG
Quad Analog Switch/Multiplexer
SW
A
IN/OUT 1
OUT/IN 2
OUT/IN 3
IN/OUT 4
CONT B 5
CONT C 6
VSS 7
14 VDD
13 CONT A
12 CONT D
11 IN/OUT
10 OUT/IN
9 OUT/IN
8
IN/OUT
SW
D
SW
B
SW
C
SIG/A
SIG/B
SIG/D
SIG/C
16
VDD
6
INHIBIT
10
A
9 B
8
VSS
7 VEE
12
X0
14 X1
15 X2
11 X3
1 Y0
5 Y1
2 Y2
4 Y3
LEVEL
CONVERTER
BINARY TO 1-OF-4
DECODER WITH INHIBIT
SW
SW
SW
SW
SW
SW
SW
SW
13 X
3 Y
IC10 : BA15218N
Dual OP-Amp
–IN
1
2
+IN
1
3
–V
CC
4
+IN
2
5
–IN
2
6
OUT
2
7
+V
CC
8
OUT
1
1
–
+
–
+
IC1 : LB1641
Motor Driver
2 3
P1
5
IN 1
1
GND
4 VZ
6
IN 2
OUT
1
8
VCC 2
10
OUT
2
9
P2
INPUT LOGIC
PRE DRIVER
7
VCC 1
IC2 :
µ
PC1330HA
2 ch Head Selector Switch
INVERTER
COMPARATOR
1
SWR 1
2
GND
3
SWP 1
4
CONT
5
GND
6
VCC
9
SWR 2
8
GND
7
SWP 2
105Hz
BPF
VREF
BIAS
340Hz
BPF
1kHz
BPF
3.4kHz
BPF
DIF
10.5kHz
BPF
PEAK
HOLD
PEAK
HOLD
PEAK
HOLD
PEAK
HOLD
PEAK
HOLD
RES
RES
RES
RES
MPX
DEC
RES
REFFERENCE
CURRENT
6
7
8
9
5
4
3
2
1
13
12
11
10
14
15
16
17
18 BIASC
VREFC
BREF
N. C.
N. C.
DIF OUT
C IN
A IN
VCC
GND
A OUT
TEST
N. C.
N. C.
SEL
C
B
A
A – C
C
A
IC26 : BA3835S
5-Band BPF and Peak Hold for Spectrum Analyzer
IC9, 11, 21 :
µ
PC4570G2
Dual OP-Amp
– +
OUT1
–IN1
–VCC
+VCC
OUT2
1
2
3
4 5
+IN1 –IN2
+IN2
– +
6
7
8
IC6 : CXA1897Q
Dolby B-Type Noise Reduction System with Recording/Playback
Equalizer
17 22 20 19
REC EQ
CTL
REC EQ
CTL
GND
D PB IN1
NRSW
GND
AGC OUT1
VCC
10K 40K
10dB AMP
IREF MUTE
36
D TC1
DR OUT1
REC IN1
DECK AB
A EQ B EQ
REC OUT1 REC OUT2
SPEED
FP CAL GP CAL REC IN2
DR OUT2
VCC
RFC
AMS OUT
AMS GAIN
35
34
32
30
29
27
26
25 12
24
D REC IN1
D IREF
GND
31
NR
D L OUT2
NR
AMS
18 21 15 16 13 14
45 46 48 47
REC
EQ
REC
EQ
11
10
9
8
7
6
AGC
IREF
AGC IN1
D PBIN2
MODE
AGC OUT2
D TC2
GND
IREF
VG
AGC TC
D REC IN2
REC MUTE
D L OUT2
AGC IN2
10K 40K
10dB AMP
5
4
33
3
2
1
44 43
GND
PB OUTB1 PB OUTA1 PB FB21 PB FB11 PB INB1 PB INA1 PB INA2 PB INB2 PB FB12 PB FB22 PB OUTA2 PB OUTB2
GND GND
41 39 37
GND GND
23
38 40
28
42
Point
e
(Pin37 of IC8)
V : 2V/div H : 20
µ
sec/div
DC range 1 : 1 probe
Point
r
(Pin39 of IC8)
V : 2V/div H : 50 nsec/div
DC range 1 : 1 probe
Point t
CH1 : Collector of Q19
CH2 : Anode of D11
H : 0.5 sec/div DC range 1 : 1 probe
V : 2V/div (CH1)
V : 2V/div (CH2)
(This waveform is not available by pushing the power switch ON and OFF.)
CH 1
CH 2
With the POWER ON,
disconnect the A/C power
cord. Reconnect the A/C
power cord and the above
waveforms will start.
Disconnect the
power cord from
the AC outlet.
0V 0V
1
2
3
4
5
6
7
8
9
10
11
12
13
1. R ¥
REC
2. METAL
3. F ¥
REC
4. CASS IN
5. C r O 2
6. +SOL
7. SENSOR OUT
8. +5V SENSOR
9. PLAY SW
10. +MTR
11. —COM
12. MTR SPEED B
13. MTR SPEED A
MAIN PCB
—
+
B
A
MABUCHI
MTR
MECHA CHASSIS PH TYPE (JST)
SOL
1
2
3
4
5
1. LOAD OUT (+)
2. LOAD IN (+)
3. LOAD OUT
4. COM
5. LOAD IN
LOADING PCB
PH TYPE (JST)
MTR
+
1. Lch
R / P HD
PH CONNECTOR
—
+
—
+
L
R
E HD
+
2. Lch —
3. Rch —
4. Rch +
5. E —
6. E +
INPUT SELECTOR
˚BUFFER
MOTOR DRIVE
MECHANISM
CONTROL
RESET
MAIN CPU
SPECTRUM
ANALYZER
REGULATOR
REGULATOR
PRE
AMP
MUTING
REGULATOR
MUTING
BUFFER
TONE
AMP
ELECTRONIC
VOLUME
CONTROL
HEAD EQ AMP
DOLBY B-TYPE
PROCESSOR
REC/PB
SW
BIAS OSC
TUNER
CD
TAPE
PB
0 0 0 8.0 0 0 0 0 0
~
~
0
0
0
0
0
0
0
0
0.7 11.2
11.2
11.5
11.2
12.2
12.2
12.2
TAPE SPEED ADJ.
BIAS ADJ.
(Lch)
BIAS ADJ.
(Lch)
0
0
0
0
0
0
0
4.9
4.6
0
0
0
0
0
23.1
0
0
0 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2.4
7.4
4.0
4.0
1.2
0
0
2.5
2.4
4.0
4.0
4.0
1.3
1.3
2.6
2.6
1.2
4.0
3.9 4.0 4.0 4.1
0.3
8.6
8.6
4.0
2.6
4.0
3.4
3.4
PB LEVEL ADJ.
(Lch)
REC LEVEL ADJ.
(Rch)
REC LEVEL ADJ.(Lch)
0.3
4.0
2.6 4.0 3.9 4.0
1.1
4.1
2.5
4.4
8.0 8.0
PB LEVEL ADJ.
(Rch)
0.5
0.7
12.2
12.2
0
0 0.5 0.7 1.0
0
0
9.0
9.0 9.0
9.0
4.7
0
0
0
0
0
0
4.7
9.0
9.0
9.0
-8.4
9.0
9.0
0
0
0
0 0
0
0
0
0
0
9.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-8.3
-8.4
4.7
9.0
-8.4
9.0
9.0
4.4
9.0
4.4
4.4
4.4
4.4
4.4
2.3
4.6
4.4
4.4
4.4
4.4
4.4
4.4
4.4
0
0
4.4
4.3
4.2
4.3
4.2
4.4
4.4
4.4 4.3
4.4 4.3 4.2
4.4 4.2 4.2 4.4
4.4
4.4 4.4
4.2 4.4
4.4
4.4
4.4
4.4
12.3
0 0
0
0
0
0
-11.9
4.9
4.9
4.8
4.8
4.8
4.7
4.5
4.6
4.7
4.7 4.7 4.7
4.7 4.7
4.7
4.6
4.6
4.7
4.7
4.1
4.1
4.7
1.8 4.8 4.8 4.8 4.8 4.8
1.6 4.6 2.1 4.9 5.1 4.6 4.7 4.7 4.5 4.7 4.7
4.7
2.1
4.7
4.7
4.4
4.8
4.8
5.5
5.5
4.7
4.6
4.9
0
0 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0 0
0
0
0
2.1
0
0
0
0
0
0
4.1
4.6
2.9
1.2
1.8
1.7
2.3
1.9
2.3
1.7
4.6
4.8
5.2
0.9
0.8
0.3
1.7 1.8
2.9
1.2
2.4
4.7
2.4
1.4
2.4 2.4
0 0
5.5
9.0
-11.9
0.7
12.3
0.7
0.4
4.9
4.9
9.0
9.6
9.6
0
4.8
5.5
12.4
12.4
5.5
2.1
5.2
0
0
0
0
0
0
0
0
0
0
0
0
12.4
9.7
9.7
0
13.0
6.1
6.1
0
0
0
0
0
0
-11.9
-11.9
-11.9
12.3
0
0
0
4.9
4.7
~
~
~
~
~
4.7
9.0
-8.4
0
0
4.7
0
0
0 0
0
0
0
0
0
0
0
0
0
0
0
0
t
r
e
( 8.1
)
( 4.6
)
(0.1)
(0.2)
(14.4)
(3.4)
(0)
(0)
(0)
(0)
(3.4)
(4.9)
(15.0)
(5.5)
(21.8)
(15.0)
(15.0)
(0)
(0)
(14.4)
(1.6)
( 4.6
)
( 0
)
(0)
(4.6)
(0)
( 0.7
)
14
7
( 4.6
)
(0.6)
( 4.7
)
( 0
)
( 0
)
(4.8)
(3.0)
(2.0)
( 3.
0
)
CASS IN CASS
CASS CASS
68
P72
I-4
SAME
PAGE
M-8
SAME
PAGE
M-9
SAME
PAGE
N-8
P74
H-6
P66
L-2
SAME PAGE
K-6
P70
E-6
P70
H-5
P73
A-4
P73
H-7
P73
A-3
SAME PAGE
B-9
P70 E-1
P72
I-6
SAME PAGE
A-7
SAME PAGE
A-5
SAME PAGE
A-6