Yamaha RX-777 Service Manual page 20

A B
RX-777
SCHEMATIC DIAGRAM (OPERATION 1/2)
1
IC302: NJM2068D-D
Dual OP-Amp
1 2 3 4 5 6 7 8
2
Point 1 Pin 15 of IC301
3
Point 2 emitter of Q305
and collector of Q307
4
A Q305 E
B Q307 C
POWER ON POWER OFF
(Connect the power cord) (Disconnect the power cord)
5
-14.6
0 0 0 0
-14.7
-14.7
6
7
6.0
5.3
6.0
-14.6
5.3
-14.6
8
P27
E1
All voltage are measured with a 10MΩ/V DC electric 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.
9 26
C D E
REGULATOR
6.0
13.9 6.0
6.7
5.3
6.7
0
RESET
A
13.9 5.7
5.7
13.2
0
5.1
5.1
0
0
2
P25
H4
6.0
6.0
6.0
6.0
6.0
6.0
6.0
5.1
-14.6
6.0
2.4
0
-14.3
8 5
0
0
7 0
6
0 0
2
1
3
4
0
-14.4
P26
I6
F G
6.0 5.3
5.2
2.3
B
0
0
0
REMOTE
5.3 5.3 5.3 0
5.3
5.3
-14.6
5.3
0 0
5.3
-14.6
5.3
-14.6
0.8
2.3
0
0.6
0
0
0
FR441
18.0
11.6
12
12.1
11.6
5.1
5.7
12.1
5.7
0
0
0
0
R216
2.2
1SS133
HZS4B2TD
HZS5A2TD
HZS5C2TD
HZS6A2TD
HZS6B2TD
HZS7A2TD
MTZJ12C
Cathode
H I
5.3 2.4
5.3 5.3
2.4 5.3
5.3 0.1
5.3 5.3
5.3 0.1
5.3 5.3
-26.6
5.3
-26.7
5.2 ~
5.3 ~
5.3
1
-26.6
0 ~
2.3 ~
2.5 ~
5.3 ~
5.3
-26.6
~
5.3
2.5
~
5.3
~
5.3
~
0
~
5.2 ~
5.2
~
P28 P26
C1 D8
SIR-481ST3F M38B59EFFP NJM2068D-D
65 41
Anode
66 40
–
~
~
+
8 4
80 26
1
1 25
J K L
FL DISPLAY
-20.8
-20.8
-26.6
-26.7
~
~
-26.6
~
~
~
~
-26.6
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
-20.8
-20.8
-26.8
-21.2
2SA933S 2SC4488 2SD2375
2SC1740S
2SD1915F
DTA144ES
E B
C B C B C
E E