Yamaha RX-497 Service Manual page 30

A B
RX-497
SCHEMATIC DIAGRAM (OPERATION)
1
2
PURE DIRECT OFF
12.8
0
0 0.1
3
0
0 0
4 -12.8
5
-22.0
~
~
~
-22.0
~
~
~
~
~
~
-22.0
6
4.9
-20.8
~
0
7
8
30
C D E
14.7
13.3
0
0
0
-14.3
0
0
-14.3
0
PURE DIRECT ON
-22.0
-22.0
~
~
~
~
~
~
4.9
2.2
2.2
0
4.8
4.8
4.8
4.8
0
0
-22.9
-22.9
-22.2 -31.4 -32.3 0.1
Page 31 B-2
TO MAIN (1) CB103
F G
IC301, 401, 751: NJM2068MD-TE
Dual OP-Amp
OUT 1 1 8 +V CC
13.3
–IN 2 7 OUT
1 2
+ – + –
+IN 1 3 6 –IN 2
–V 4 5 +IN
CC 2
14.2
0.1
0.1
-13.9
IC431: LB1641
Motor Driver
0
0.6
0.8
0
0.9
1.8
0.1
14.3
14.3
0.8
0.6
IN 1 5
GND 1
Page 31
TO MAIN (2) W293
-16.6
-19.4
-19.4
-22.2
H I
PURE DIRECT OFF
0.1
0.1
0.1
0.1
3 2 8 10 9 7
IC801: M66003-0131FP
Display Driver
Display code
4 VZ
RAM
(8-bit x 60)
Code
write
Serial dot data
CS 2 data
write
receive
SCK 3
Code/
circuit
INPUT LOGIC IN 2 SDATA 4
6 command
control
circuit
code
select
XIN 7
Clock
timing Display
generator clock scan pulse
J-5 XOUT controller
6
RESET 1
Vcc1 8
Vcc2 18
Vss 5
Vp 64
12.8
0
0 0
0
0 0
-12.8
J K
CGROM
44 SEG00
(35 bit x 166)
Segment 19 SEG25
output
17 SEG26
circuit
CGROM
9 SEG34
(35 bit x 16)
45 SEG35
DIG11/
52
SEG42
DIG12/
51
SEG41
Segment DIG13/
50
digit SEG40
select/ DIG14/
49
output SEG39
circuit DIG15/
48
SEG38
DIG16/
47
SEG37
DIG17/
46
SEG36
63 DIG00
Digit
output
circuit
53 DIG10
* All voltages are measured with a 10M Ω /V DC electronic 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.
L