Yamaha GX-700 Service Manual page 53

A B C
SCHEMATIC DIAGRAM (GX-700 CD)
1
2
3
4
ACT
MOTOR
DRIVE
5
6.3 6.3
6.2 2.5
2.4 2.4
2.4 2.4
2.7
2.4
3.0 2.7
0
0
0
2.8
2.7 2.4
2.4 2.4
2.4
6
6.2
0
0
7
8
MOTOR DRIVE
9
10
D E F
CD HEAD AMP
0
SPC & DAC
2.5
1.2
2.5
2.2
4.9
0
0
2.4
2.3
4.9
0
0
0
3.1
q
2.4
0.8
2.5
0
4.7
6.2 0
0
G H I
4.8 5.5
REGULATOR
REGULATOR
4.9 8.5
6.3 11.1
7.9
1.8
6.8
1.2
0 1.2 7.9
0 1.2
6.8
0
2.7
0 0
0
0
4.8
14
4.8 12 4.8
11
0 13
4.8
14
0
4.7 10 11
4.7
10
~ 9 4.8
8
4.7
4
5 6 ~
0
8 9
0
0 0 4.7
7
1
2
3 ~
~
0
7
4.3
4.9
0
~
4.7
0
0
0
0
4.7
~
~
2.4
0
4.9
~
2.4
2.4
4.8
w
0
0
4.3 0
4.7 0
0
CD CPU
0
2.1
0
2.3 0
0 4.8
0
0
0 0 0
0 0
0 0
0 0
0 0
0 0
4.8 0
0 0
0 0
12.4
0 3
8
1 0
0 2
0
LPF
0
0
0
0 6
0
7
0
5
4
-12.0
J K
MAIN(1)
P73
A-2
6.8
0
0
INPUT(1)
EFFECT(1)
P72
I-5
Point q (Pin59 of IC5)
V : 5V/div
DC range
0V
Point w (Pin39 of IC11)
V : 2V/div
DC range
0V
0 3
4 4.8
4.8
0 1 5
6 0
2
CD(Lch)
IC3, 4 : TA8409S
MUTING
Full Bridge Motor Driver
VCC VS
4.8
2 6
-11.9
VREF
STAND-BY
CIRCUIT
CIRCUIT
4.8
-11.9
IN 1
9
-11.9
IN 2
1
THERMAL
SHUTDOWN
CIRCUIT
5
GND
L M N
GX-700/GX-700VCD
IC2 : AN8803SB
Digital Servo Head Amp
6 7 29 27 28 8 9 10 17 11 12 19
+
+
RF
EQ AGC
DETECT
VCBA
PDAC
36 +
+
ENV DETECT
C.SBDO
BDO 13
14 BDO
VCBA
PDBD 15 C.SBRT
35 OFTR
+
+ +
16 OFTR
+
20 VREF
PDFR 31
VCBA
PDF 34
+ 5 VCC
+
+
18 GND
VCBA
+
PDER
32 21 LD OFF
P68
+
A-9 + + 2 LD
PDE 33 +
+
+
30 24 25 26 23 22 1 4 3
IC1 : LA6541D
4 Channel BTL Driver
–
VCC 1 30 VCC
+
MUTE 2 29 VREF
11KΩ LEVEL SHIFT LEVEL SHIFT 11KΩ
VIN1 3 28 VIN4
1 4
VG1 4 27 VG4
BTL AMP BTL AMP
VO1 5 26 VO8
1 4
VO2 6 25 VO7
VCC
GND 7 24 GND
–
GND 8 23 GND
+
GND 9 22 GND
VO3 10 21 VO6
BTL AMP BTL AMP
VO4 11 VO5
20
2 3
VG2 12 19 VG3
LEVEL SHIFT LEVEL SHIFT
VIN2 13 18 VIN3
11KΩ 2 3 11KΩ
REG OUT 14 17 CD
REG IN 15 REGULATOR RESET 16 RES
IC7, 9 : TC74HC125AF
Quad 3 State Bus Buffers
1C 1 14 Vcc
1A
2 13 4C
1Y 3 12 4A
2C 4 11 4Y
2A 5 10 3C
2Y 6 9 3A
GND
7 8 3Y
H : 50 nsec/div
1 : 1 probe
IC13 : TC74HC04AF
Hex Inverters
1A 1 14 V
DD
1Y 2 6A
13
2A 3 12 6Y
2Y 4 11 5A
3A 5 10 5Y
3Y 6 9 4A
V SS 7 8 4Y
H : 50 nsec/div IC8 : TC74VHC14F
Hex Schmit Trigger Inverters
1 : 1 probe
I1 1 14 V
DD
O1 2 13 I6
I2 3 12 O6
O2 4 11 I5
I3 5 10 O5
O3 6 9
I4
V SS 7 8 O4
µ
IC10 : PC4570G2
Dual OP-Amp
OUT 1 8 +V
1 CC
–IN 1 2 7 OUT 2
+ – + –
+IN 1 3 6 –IN 2
8 VREF –V CC 4 5 +IN 2
7 OUT 1
3 OUT 2
* 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.
66