Yamaha GX-505 Service Manual page 53

A B
SCHEMATIC DIAGRAM (GX-505 OPERATION)
1
µ
IC807 : PC4570HA
Dual OP-Amp
1 2
– + + –
1 2 3 4 5 6 7 8 9
V V –Vm +Vm V +Vm –Vm V V
CC O1 1 1 EE 2 2 O2 CC
IC804 : YSS247-D
2
YMERSION
11 8 3 2 1
AVDD 14
FILTER
+1
VREF 17 VREF
SWITCH –1 SWITCH
TO SWITCHES YMERSION
–1
SWITCH SWITCH
3
SW
13
+1
COMPARATORS
FILTER
AVSS 15
12 10 7 6 5
IC802 : BU2092
Serial In/Parallel Out Driver
VSS 1 18 VDD
4
DATA 2 17 OE
CONTROL
CLOCK Q11
3 16
CIRCUIT
LCK 4 Q10
15
Q0 5 14 Q9
Q8
Q1 6 13
Q2 12 Q7
7
Q3 8 11 Q6
Q4 9 10 Q5
5
6
7
8
C D E
MUTING
24 23 22
SWITCH
+1
TONE CONTROL
+1
SWITCH
20 19 18
P64
G-9
4.9
4.9
0
F G
P64
H-2
0
-6.1
0
0
-6.1
0
4.9 12.3
0
12.9
0 3 1
2
0 4 0
0 6
8
0 7
0
5
-11.9
BUFFER
4.8
4.9
0.9
0
0
0.6
YMERSION
LED DRIVER
IC803 : M66004MASP
FL Driver
DISPLAY CODE
CS 14 SERIAL
REGISTER
RECEIVE
SCK 15
(8BITx16)
CIRCUIT
SDATA 16
CODE
WRITE
CORD/
COMMAND
RAM
CONTROL WRITE
CIRCUIT
DISPLAY
CONTROL
RESET 13
CODE
REGISTER
SELECT
XIN 21
CLOCK DISPLAY
GENERATOR CONTROLLER
XOUT 20
H I
-27.4
-22.0
P64
H-9
CGROM
(35BITx160) 59 SEG00
SEGMENT 33 SEG26
OUTPUT
31 SEG27
CIRCUIT
CGRAM
23 SEG35
(35BITx16)
OUTPUT 18 P0
PORT
(2BIT)
17 P1
12 DIG00
DIGITAL
1 DIG11
OUTPUT
CIRCUIT 64 DIG12
DIG15
61
J K
GX-505/GX-505VCD
FL
DRIVER
* 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