Schematic Diagram - Yamaha YST-SW320 Service Manual

A B

SCHEMATIC DIAGRAM

1
11.8
0
0 0
L.P.F.
2
0
0
0
-11.9
3
H.P.F.
11.8
-11.9
0
0
0
0
0
0
4
AC 97.6V
5
6
7
PIN CONNECTION DIAGRAM OF TRANSISTORS, DIODES AND ICS.
8
1SS133 S1NB20 RBV-602 2SA970 (GR, BL)
S2L20U 2SA1015 (Y)
1SR139-400 2SA1145 (O, Y)
MTZJ3.6B 2SC1815 (Y, GR)
MTZJ12.0C 2SC2240 (GR, BL)
MTZJ24.0B 2SC2705 (O, Y)
2SC2878 (A, B)
Anode
–
–
E
C
Cathode +
+ B
C D E
B.P.F. L.P.F.
-11.9
0
0
2.7 3.4
5.9
0
-0.1
3.4
0
0.6
0
0
-0.1
0
0
0
0
LIMITER
11.8
0 0 0
0 0.1
-11.9 11.8
0.1 0.1
0 0
0 0
0 0
0
0
0 1.8
0.6
0
7.3
L.P.F.
7.9
A.N.I.C
11.8
-0.3
0 0
0
0
0
0
-0.3
0
0
-11.9
-11.9
POWER SUPPLY
0 16.4 11.8
0
AC 25.9V
-16.4
16.4
0
0
-16.4 -11.9
SUB
POWER SUPPLY
AC 11.2V
5.6
0
11.5
5.6
2SC1846S 2SA1837 2SA1492Z (O, P, Y) 2SK304 (E, T) NJM78L08A
2SC4793 2SC3856Z (O, P, Y)
2SC4688 (R, O)
1:OUTPUT
2:COMMON
D
3:INPUT
E C G
B B
B C E C S
E
F G
POWER DRIVE
PRE DRIVE
62.9
63.1
62.4
62.1 62.1
4.2
61.6
61.6 61.6
1.7
1.7
0.7
1.1
1.7
-1.0
-1.6
0.7
0
0.2
IDLING CURRENT ADJ.
-61.8 -61.8
-3.6
-1.0
-61.8
-61.9
-1.6
-1.6
-61.4
-62.8
-61.8
-61.9
-62.5
-61.4
-62.5
-61.4
POWER SUPPLY
0
-62.8 63.1
0
0
-1.5
0
11.8
0 0
0
0
0
6.0
6.6
11.5 7.9
0
AUTO POWER ON/OFF
CIRCUIT
7.9
11.5
0
6.7
6.6
3.9
0.9 1.3
3.9
0
0.7
0
NJM78M12FA µPC4570HA
NJM79M12FA NJM4558L
µPC1237HA
M51848L
8 9
1: OUTPUT
1:COMMON
2: COMMON 2:INPUT
1
2 3
3: INPUT 3 2 3:OUTPUT 3 2
1 1
1
1
H I
PS AMP
63.0
62.6
63.1
63.1 63.1
63.1 A
62.4 63.1
4.2 62.7 62.7
2.6
3.6 62.6
3.6
B
3.2
2.6 0
1.1
2.6
63.1
0.6
62.4
0.6
0
62.4
0
0
0
-0.5
0
DC 50mV to 250mV
-0.5
-2.6
-1.0 -2.7
-3.2 0
-2.7
-62.3
-3.6
-2.6
-62.3
-4.2 -62.8
-63.4
-63.1 -63.4
-62.8 -62.8
-62.8
-62.8 62.8
-62.9
PROTECTION
6.0
24.3 0.7
6.6
7.5
0
0
J K
YST-SW320
µ
IC1, 4, 7—9 : PC4570HA
Dual OP-Amp
1 2
– + + –
1 2 3 4 5 6 7 8 9
V CC V O1 –Vm 1 +Vm 1 V EE +Vm 2 –Vm 2 V O2 V CC
IC11 : NJM4558L
Dual OP-Amp
+ +
– –
1 2 3 4 5 6 7 8
µ
IC3 : PC1237HA
Protector IC for Power Amplifier
Vcc
7 8
Relay
Overload Vcc on
1 drive 6
detect mute
circuit
Flip flop
circuit
Mid-point
AC OFF
2 potential
detect
detect
Latch / automatic
return select
5 3 4
GND
IC5 : M51848L
CR Timer
R R R
–
+
FLIP-
FLOP
1 6 8
2 3 4 5 7
* All voltage are measured with a 10MΩ/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.
14