Yamaha YHT-S300, Service Manual

Page: 84 / 103

A
1
2
3
4
5
6
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8
9
10
B C D E F G H I J K L M N
SR-300/NS-BR300/NS-P705/NS-B380
84
POWER 2/2
★
All voltages are measured with a 10MΩ/V DC electronic voltmeter.
★
Components having special characteristics are marked ⚠ and must be replaced
with parts having specifications equal to those originally installed.
★ Schematic diagram is subject to change without notice.
● 電圧は、内部抵抗 10MΩの電圧計で測定したものです。
● ⚠印のある部品は、安全性確保部品を示しています。部品の交換が必要な場合、
パーツリストに記載されている部品を使用してください。
● 本回路図は標準回路図です。改良のため予告なく変更することがございます。
IC851
CB953 CB954
3.4
0
3.4
-30.2
-24.1
-24.1
-30.2 -30.2 -30.1
-24.6
-30.1 -30.1 -30.1 -30.1
-30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.2 -30.2 -30.2
-32.2
-24.6 -24.6 -24.6 -15.4 -26.3 -26.3
3.4 3.4
3.4
3.4 0 0 0 0 0 0
0
12.3
-32.2
3.4
3.4
0
0.2 3.3
3.3
3.3
-10.1 -10.1 -19.0
3.3
-28.2
-28.2 -32.8
-17.4
-8.2
-30.1
-28.1
-31.9
-15.4
-12.0
-17.4
-11.8
-19.4
-11.7
-30.1
-30.1
-28.2
-11.8
-17.3
-15.5
-30.1
0
3.4
0
0
0 0
0 3.3 3.4
0
2.0
-29.8
3.3
-30.1
-29.8
3.4
3.4
3.3
3.3
-11.9
-11.2
-11.8
3.3
3.3
3.4
3.4
1.6
1.6
0
0.2
-10.0 -19.2 -30.0 -17.3
-30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -30.1 -29.8 -29.8 -11.7 -11.8 -17.4 -17.4 -22.8 -24.6 -24.6 -26.4 -15.4 -26.3 -26.4 -26.3 -10.1 -10.0 -10.1 -19.2 -19.0 -28.2 -28.2 -28.2 -11.8 -17.3 -15.5 -15.2 -11.8
-24.1
-24.1
-11.9 -30.0 -17.3 -12.0 -15.4 -31.9 -28.1 -30.1
-8.2
-19.4
-0.5
-0.5
-17.3
-17.3
-32.2
-24.2
12.2
12.2
0
0
-32.2
0
-17.3
-17.3
-32.2
0
52
Display
controller
Serial
receive
circuit
Digit
output
circuit
Clock
generator
DIG11/
SEG42
51
DIG12/
SEG41
50
DIG13/
SEG40
49
DIG14/
SEG39
48
DIG15/
SEG38
47
DIG16/
SEG37
46
DIG17/
SEG36
45 SEG35
XOUT 6
Vcc1 8
Vcc2 18
Vss 5
Vp 64
XIN 7
CS
SCK 3
SDAT A A A T T 4
RESET 1
SEG00 44
9 SEG34
SEG26 17
19 SEG25 Segment
output
circuit
Display code
RAM
(8-bit x 60)
CGROM
(35-bit x 166)
CGROM
(35-bit x 16)
code
select
Code
write
Code/
command
control
circuit
DIG00 63
53 DIG10
IC851 : M66003-0131FP-R
18 digit 5 x 7 segment VFD controller/driver
2 data
timing
clock
dot data
write
scan pulse
Segment/
Digit
select/
output
circuit
POWER (3)
FL DRIVER
SPEAKERS
POWER (2)
STATUS
indicator
to MAIN_CB307
Page 82 B6
to MAIN_CB309
Page 82 B2
to MAIN_CB303
Page 80 K6
Ohm 0 + 6.8 k + 22 k
V 0 – 0.2 1.2 – 1.5 2.3 – 2.6
A/D value
(3.3 V=255)
0 – 15 95 – 115 180 – 200
KEY1 (127 pin) VOLUME - INPUT
Key destination for A/D port
Key input (A/D) pull-up resistance 10 k-ohms