ABCDEFGH
1
2
3
4
5
6
IJKL
7
8
MDX-596
* All voltages are measured with a 10MΩ/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.
Point q (Pin 13 of IC6)
V : 2V/div H : 20 µsec/div
DC range 1 : 1 probe
Point w
CH1 : Emitter of Q2
CH2 : Collector of Q14
V : 2V/div CH1
V : 2V/div CH2
H : 5 sec/div DC range 1 : 1 probe
0V
CH 2
CH 1
AC CORD
ON
AC CORD
OFF
■ SCHEMATIC DIAGRAM
IC1 : TC74HCT04AP
Hex Inverters
IC3 ~ 5 : NJM2068D-D
Dual OP-Amp
–+
OUT
1
–IN
1
–V
CC
+V
CC
OUT
2
1
2
3
4
5
+IN
1
–IN
2
+IN
2
– +
6
7
8
1A
1Y
2Y
V
DD
6A
1
2
3
4
11
2A 6Y
5A
12
13
14
3A
3Y
5Y
4A
5
6
7
V
SS
4Y8
9
10
IC2 : TC74VHC157F
2 to 1 Data Selectors
G4A4B4Y3A3B
1A 1B 1Y 2A 2B 2Y
3YS
15
STROBE
2
1A
14
4A
13
4B
12
4Y
11
3A
10
3B
9
3Y
1
SELECT
3
1B
4
1Y
5
2A
6
2B
7
2Y
8
16
VCC
GND
INPUTS
OUTPUT
OUTPUT
INPUTS
INPUTS
OUTPUT
OUTPUT
INPUTS
INPUTS
X
L
H
H
L
L
L
A
B
SELECT
STROBE
G
OUTPUT
Y
FUNCTION TABLE
VCC
E–
C+
NC
OUTPUT
(+5V)
DELAY
RESET OUT
BAL. ADJ.
GND
ON/OFF
E– C–
NC
–VCC
DELAY
CIRCUIT
REFERENCE
REGULATOR
PROTECTION
ON/OFF
CONTROL
REFERENCE
IN
+
+
CURRENT
CONTROL
CURRENT
CONTROL
16 15 12 7
9
10
3
2
4
6
11
8
1
14 13
5
OUTPUT
(–5V)
CURRENT
CONTROL
IC8 : M5290P
Constant-Voltage Tracking Supply with Reset
IC201 : BA15218N
Dual OP-Amp
–IN
1
2
+IN
1
3
–V
CC
4
+IN
2
5
–IN
2
6
OUT
2
7
+V
CC
8
OUT
1
1
–
+
–
+
START / STOP
LOGIC
ADDRESS
COUNTER
LOAD
LOAD
COMP
R/W
D
OUT
DIN
INC
Y DECODER
DEVICE
ADDRESS
COMPARATOR
DATA
REGISTER
SELECTOR
E
2
PROM
X
DECODER
DATA OUT
ACK OUT
CONTROL
6
7
5
4
3
2
1
SCL
TEST
SDA
V
CC
GND
A2
A1
A0
SERIAL
CLOCK
CONTROL
8
H.V.GENERATOR
IC7 : S-24C01ADP
Electrically Erasable PROM
E-49/J-47
MAIN CPU
LPF
MUTING
BUFFERBUFFER
MUTE CONTROL
RESET
POWER
SUPPLY
AMP
PHONES
EEP
ROM
DIGITAL INPUT
SELECTOR
1
8
3
2
7
6
5
4
CIRCUIT CHANGES BY MARKET.
X : NOT USED
0
0
0
4.9
q
w
10.2
10.6
11.2
-12.3
-12.8
-13.5
AC21.3
AC4.2
0
0
0
0
0
0
0
0
4.9
5.0
5.0
0
0
0
0
6.0
-6.0
0
0
0
0
6.0
0
0
-6.0
0
0
0
-5.9
0
0
0
0
-5.9
0
-5.9
0
0
-5.9
0
4.4
4.4
4.9
-6.0
4.9
0
-6.0 -13.3
-13.3
-12.6
4.9
1.3
-6.0
0
-12.6
0
-13.2
0
1.2
6.0
0
10.7
0
11.2
10.9
11.2
10.7
6.0
11.3
6.2
0
0
0
6.2
0
0
4.9
11.3
5.4
5.0
10.6
10.6
-13.4
-24.2-35.4-35.4
-29.6
0
-28.9
-28.9
0
4.9
4.9
0
0
0
0
0
4.9
2.4
0
2.1
5.0
5.0
~
4.2
4.4
0
0
0
0
0
0
0
0
4.9
4.9
4.9
0
5.0
0
0.2
0.6
4.8
4.9
0.1
~
4.5
0
0
0
0
4.9
0
0
0
0
0
5.0
5.0
4.9
0
0
0
0
0
0
0
0
0
0
0
5.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
~
4.9
0.1
4.0
0
0
0
0
0
5.0
4.0
0
4.9
3.6
3.6
0
3.2
1.9
~
~
~
~
~
4.9
4.9
0
0
6.0
0
0
0
-6.0
0
0
0
1.9
0
4.9
~
~
5.0
4.0
0
5.0
1.6
0
0
0
0
0
0
0
0
0
-24.2
0
1.2
-13.2
4.4
0
0
0
0
0
0
P-E48/J46
[K-7]
P-E50/J48
[A-4]