Yamaha GX-700 Service Manual page 59

A B
SCHEMATIC DIAGRAM (GX-700/GX-700VCD EFFECT)
1
µ
IC7 ~ 9 : PC4570HA IC11 : LM1875T
Dual OP-Amp Power Amp
+
1 2 –
– + + –
1 2 3 4 5 6 7 8 9
1 2 3 4 5
V V –Vm +Vm V +Vm –Vm V V
CC O1 1 1 EE 2 2 O2 CC
2
POWER AMP
23.5
0
0
0
-24.1
SAME PAGE
I-8
3
0
2.1
0
VIDEO SW & AMP
4
VIDEO AMP
12.4
6.9
6.9
5
6.9
6.2
7.9
7.9
0
P67 0
K-3
GX-700VCD ONLY
6
4.5
4.5
5.2
4.5
i
5.2
4.5
4.5
4.5
4.3
4.3
7
4.4
5.2
4.5
5.2
4.5
4.5
8
DOLBY PROLOGIC DECODER
C D E
IC1 : LA7956
Video Amp
6 dB
AMP
4-INPUT 1-OUTPUT
CONTROL
VIDEO SWITCH
DRIVER
1 2 3 4 5 6 7 8 9
VIDEO A B VIN1 GND VIN2 VCC VIN3 VIN4
OUT
0
-0.8
0
-23.9
P73 H-8
0
0
0
0
2.5
0 0
9.0
2.4
0
5.0
4.5 0 0
0 9.0
4.5
-8.5 9.0
4.5
0 9.0
4.5
4.5
4.5
4.5
0
0.7
2.5
9.0
12.3
0 4
4.5 9 2
0 3
0.1
0 7
8 0.1
0 6
5
-12.1
F G
IC2 : HD14053BP
Triple 2 Channel Analog Multiplexers/Demultiplexers
VDD
16
CONTROL INPUTS "ON" CHANNEL
INHIBIT C B A 0X (Pin 12), 0Y (Pin 2), 0Z (Pin 5)
(Pin 6) (Pin 9) (Pin 10) (Pin 11) 1X (Pin 13), 1Y (Pin 1), 1Z (Pin 3)
X-COMMON
14 L L L L 0X, 0Y, 0Z
L L L H 1X, 0Y, 0Z
L L H L 0X, 1Y, 0Z
A OUT C IN 12 OX
11
L L H H 1X, 1Y, 0Z
L H L L 0X, 0Y, 1Z
OUT C IN 13 IX L H L H 1X, 0Y, 1Z
L H H L 0X, 1Y, 1Z
B L H H H 1X, 1Y, 1Z
10 OUT C IN 2 OY
H * * * NOTE
* Don't Care
OUT C IN IY
1
C 9
OUT C IN 5 OZ
OUT C IN 3 IZ
INH
6 4 Z-COMMON
15 Y-COMMON
8 7
VSS VEE
Point i (Pin32 of IC5)
H : 0.1 µsec/div
V : 2V/div
DC range 1 : 1 probe
0V
9.0
0
LEVEL CONTROL
0
0
0 7 0.9
3
8
0
0 2
0 9
12.2
5 4
6
-12.0
0 0.7
0
-12.0
0 6 0 12.2
9
5 0.2
0 4
8
0 7 0 2
3
H I
IC5 : LV1035M
Dolby ProLogic Decoder
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
L–BPF3 49 32 OSC
DC–CUT 50 31 OSC
51 30
R RECT VDD
DC–CUT 52 29 A/D
L RECT 53 28 NS
VLR–TH 54 27 D/A
VLR–1 55 26 DC–CUT
VLR–2 56 25 DC–CUT
VCS–2 57 L 24 L–MIX–OUT
VCS–1 58 23 R–MIX–OUT
R
VCS–TH 59 S 22 S–OUT
L+R RECT 60 21 ANALOG–GND
DC–CUT 61 20 NR–IREF
L–R RECT 62 19 NR–DET
63 18
DC–CUT VCC
R–BPF3 64 17 DELAY–OUT
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
P68 A-4
P69 A-4
P66 L-3
P67 K-3
9.0
0
0
P68 E-1
P69 E-1
SAME PAGE
A-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.
J K
GX-700/GX-700VCD
IC10 : LC7536-Y
Electric Controlled Volume
5 6 8 23 25 26
L5dB IN 1 30 R5dB IN
L CT1 R CT1
3 28
L CT2 4 27 R CT2
LVM 9 22 R VM
S VDD
12 LEVEL SHIFT 13
CE 19 21 VCC
LATCH
CLK 17 14 VSS
DI 18 SHIFT REGISTER 10 VEE
2 7 11 15 16 20 24 29
NC
72