Yamaha YSP 800 - Digital Sound Projector Five CH..., Service Manual

Page: 60 / 82

A
1
2
3
4
5
6
7
8
9
10
B C D E F G H I J K L M N
YSP-800
SCHEMATIC DIAGRAM (INPUT 2/2)
60
★
All voltages are measured with a 10M
Ω
/V DC electronic volt meter.
★ Components having special characteristics are marked
s
and must be replaced
with parts having specifications equal to those originally installed.
★
Schematic diagram is subject to change without notice.
POINT B-1 P.C.B. INPUT
① C531(+)
AC cable
ON
② Q504(C)
AC cable ON AC cable
OFF
0
113.2
332.4
112.3
33.2
453.5
331.8
331.8
1.0
1.0
0.1
0
0
0
0
15.1
15.1
0
0.1
0.1 0.1
0.1
0.1
1.3
1.5 0.1
0
0
3.9
15.1
0.1
0
0
0
0
15.2 15.2
15.2
7.7
7.7
0
0
0
0
0
0
10.1
10.9
5.0
5.0
10.9
5.1 10.1
5.1
5.1
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
1.0 1.0
0
2.8
2.8
10.3
10.3
0.1
0
0.1
0.8
0
0
0
0
0
0
0
0
0
0
0
0
10.3
10.3
10.3
4.0
4.0
3.3
3.3
4.0
4.0
0
0
0
0
0
3.3
3.3
3.1
3.1
3.1
3.2
0 -26.4
-25.8
-24.8
3.3
0
4.9
2 1
B-1
AC 4.8
2700
8200
ISS355
WG41030 WG41030 WG41030
INPUT(1)
SWITCHING
POWER SUPPLY
RESET
CIRCUIT
IC509 : NJM78M05FA
IC510 : NJM78M12FA
Voltage Regulator
INPUT
OUTPUT
COMMON
IC505 : FA3641N
PWM control IC
REF
FB
5V VCC
EMB
5V REF
0.82V~0.68V
8.5V~7.9V
6.5uA
0.9mA
0.8V
CS VCC
15.5V
15.5V
UVL0
16.5V/9V
OUT
GND
RT IS+
EMB
OUTPUT
R
QB
FF
Q
S
PWM
0.24V
OSC
RM RT
Dmax
70%
3.0V
4V
+
–
+
– +
–
+
–
+
–
+
–
+
–
+
–
–
–
IC502 : TC4013BP
Dual D-type Flip Flop
4
RESET1
1 Q1
6 SET1
5
DATA1
CL
3
CLOCK1
CL
CL
CL
CL
CL
2 Q1
10
RESET2
13 Q2
8 SET2
9
DATA2
7 VSS
14 VDD
11
CLOCK2
12 Q2
CL
CL
CL
CL
CL
CL
7
2
1 3
4
5
6 8
-
+
Error Amp.
Star
ter
V
o
ltage
Ref
e
rence
Input Short Circuit
Protection
Ov
er Current
Protection
Over Current
Protection
Rush Current
Protection
Thermal
Protection
IN
1
GND
3
OUT
2
IC506 : AN77L04
Low Dropout Voltage Regulator
CATHODE
REFERENCE
ANODE
K A
R
IC507 : NJM431
Adjustable Precision Shunt Reglator
Page 58
to AMP_CB708
L4
Page 59
to INPUT(2)_CB4
G4
Page 59
to INPUT(3)_CB901
G6
Page 57
POWER CABLE
to DSP_CB10
J6
5 k-ohms
10 W
Safety measures
• Some internal parts in this product contain high voltages and are dangerous. Be sure to take safety measures during servicing, such as wearing insulating gloves.
• Note that C523 is dangerous even after the power is turned off because an electric charge remains and a high voltage continues to exist there.
Before starting any repair work, perform discharge by connecting a discharge resistor (5 k-ohms/10 W) between C523 terminals.
安全対策
・この製品の内部には高電圧部分があり危険です。修理の際は、絶縁性の手袋を使用するなどの安全対策を行ってください。
・C523には電源をOFFにした後も電荷が残り、高電圧が維持されており危険です。
修理作業前に放電用抵抗（5 kΩ/10 W）をC523の端子間に接続して放電してください。