© 2000-3 PRINTED IN JAPAN
B51-7600-00 (S) 3344
SERVICE MANUAL
CASSETTE RECEIVER
KAC-719
SUBW
OOFER
AMPLIFIER
KA
C-7
1
9
Dressing panel
(A21-4014-03)
Heat sink
(F01-1627-01)
Screw terminal
board
(E70-0820-05)
Accessory (E type only)
(W01-0797-05)
Fuse
(F52-0015-05)
Screw set
(N99-1587-05)
SUBWOOFER
AMPLIFIER
L
12dB
6dB
BASS
BOOST
OFF
INPUT
SENSITIVITY(V)
LPF
FREQUENCY(Hz)
GND
R
LINE IN
25Hz
15Hz
INFRASONIC
OFF
0.3
0.5
1
2
3
4
5
0.2
150
170
100
70
50
200
LEFT
RIGHT
SPEAKER LEVEL INPUT
POWER IN
FUSE (30A)
BATT
GND
P.CON(REMOTE)
SPEAKER OUTPUT
30
SERVO II
SERVO II
Pin jack
(E63-0834-05)
Screw terminal
board
(E70-0818-05)
Screw terminal
board
(E70-0808-05)
Screw terminal
board
(E70-0824-05)
Accessory
(W01-1515-05)
ADJUSTMENT
KAC-719
2
CIRCUIT DESCRIPTION
SP P-CON Switching Circuit
When the SP output from the head unit is connected to SP IN, the power can
be switched ON/OFF based on the DC voltage of the SP output. However, As
certain head unit models output DC permanently or generate a click during
switching OFF, it is required to provide the capability of previous P-CON
switching. A circuit which can perform the switching without using a switch
is described below.
This circuit performs switching by inhibiting the operation of the S-P-CON
circuit when a voltage is applied to the P-CON pin.
Circuit operation description
When the head unit is connected to SP-INN, the DC component in the SP output
turns Q38 ON through D32 and R158.
When a voltage is applied to the P-CON pin under this condition, Q45 is
turned ON via R188, positive feedback is applied by combination of Q45 and
Q46, Q45 and Q46 are held at ON, so the voltage at point (A) is almost 0 V
and the SP-P-CON circuit is not activated.
This circuit holds the ON status while the DC voltage from SP is present.
Therefore, in this condition, the P-CON circuit continues functioning. To
cancel the functioning, the voltage at the SP-IN pin should go 0 V.
Q46
4.7k
R158
to P-CON terminal
from SP-P-CON
D32
R188
100k
10u
35
3.3k
Q45
A
Q38
power control
D29
7.5v
No
ITEM
INPUT
SETTINGS
OUTPUT
SETTINGS
TUNER
(RECEIVER)
SETTINGS
ALIGNMENT
POINTS
ALIGN FOR
FIG.
Connect a cassette receiver or other receiver.
1
IDLE
CURRENT
Connect a DC
voltmeter to CN3
Volume : 0
VR3
After sufficient aging
adjust to 2mV
(a)
Refer to the schematic diagram for the values of resistors and capacitors.
3
4
A
B
C
D
E
F
G
I
H
1
2
3
4
5
6
7
AUDIO UNIT
PC BOARD (Component Side View)
AUDIO UNIT
(X09-5320-10)
18
16
X09-5320-10 A/3 (J74-1030-11)
9
1
17
14
B
BE
E
B
E
B
E
B
E
B
E
B
E
B
E
B
B
E
E
B
B
E
B
E
B
E
1
2345678
B
E
B
E
B
E
E
B
E
B
E
B
B
B
E
BE
E
B
E
B
E
B
E
B
E
E
B
E
B
E
B
E
BE
BE
BE
BE
BE
BE
BE
BE
BE
BE
G
D
S
G
D
S
G
D
S
G
D
S
8
4
85
S1
INFRASONIC
OFF/15Hz/25Hz
BASS BOOST
OFF/6dB/12dB
C22
R91
W4
R42
R88
R102
D8
Q13
Q6
Q11
D7
R77
R101
R103
R80
R81
R105
R106
R104
R83
R82
R52
R44
R43
Q10
Q9
Q4
Q3
D5
Q15
Q5
Q7
Q8
Q12
Q16
C61
C38
C62
VR3
W15
W17
W28
R187
R162
R107
R109
C63
C64
R19
R165
R164
R163
R108
R110
W30
W33
W34
W32
W16
W40
W46
W48
W47
W45
W41
D20
D18
D17
D15
D16
D13
D14
D12
D19
W20
TH1
W22
W25
W27
W29
W31
W44
W51
D11
D9
D6
W52
W53
W54
C39
W55
W73
W76
R76
C40
C47
C21
R84
R9
R8
R28
R14
R15
R10
R27
C6
C12
D3
D4
R37
R41
R38
W19
W23
W26
W42
W39
W18
Q14
R46
R49
R47
W38
W37
W43
W56
C3
R3
R4
C4
C7
C9
C8
C67
C68
C75
W97
C10
IC3
C57
C59
R140
R112
R114
R116
R113
R157
W117
R141
R111
R115
R137
R131
R132
C54
C53
R139
W109
W110
W113
W114
W115
R134
R138
R136
W201
CN4
L1
L2
C56
TH2
R159
W100
W103
W104
W105
W106
W107
W108
W99
W112
W119
R142
R143
R144
W101
W102
W121
W125
W122
R133
W118
W123
W202
C55
R135
W120
W124
E2
J2
X09-C/3
J1
E1
X09-B/3
W116
C58
CN1
R39
VR1
R32
R33
R36
R35
R40
C5
C1
C2
R1
R2
R5
R6
R7
R34
C14
C15
W58
W80
R184
R185
W87
W96
W98
R170
R160
R194
W92
W90
W88
R23
R22
R21
R24
W57
R31
R50
W14
R92
R86
W1
W21
R90
R89
R85
R87
R166
R167
R168
Q41
Q28
Q27
W13
W2
W6
W8
(a) 2mv
CN3
IC4 R161
C71
C72
C73
C74
W7
W3
W5
D10
W36
W50
W49
R78
R13
R25
R26
W59
W60
W61
W74
W71
W72
R180
R179
R186
R182
R178
R175
R171
R173
R174
R172
R177
R176
W82
W81
R67
R63
R62
C32
C33
C36
C37
R69
C35
W79
W84
W86
C51
C52
C34
C11
C76
C65
C66
CN2
R229
R228
R118
R120
R117
R119
C31
R16
R61
R66
R65
R70
R68
R18
W68
W69
W70
R226
C46
C45
C77
C42
R96
C78
C44
C43
K1
C79
W77
W78
R227
R17
R155
R156
R151
R153
R154
R158
R152
J3
J4
R169
R224
R225
J5
R95
R193
R188
W63
W62
R93
R79
R74
R72
R71
C48
W65
W66
W83
W95
C70
C69
W89
W85
W91
W93
W94
R20
R64
W67
R12
R181
R183
W75
W64
D2
Q23
Q21
Q1
Q2
Q46
Q45
Q39
Q38
Q37
D29
D32
D30
D39
Q24
Q40
Q20
Q19
Q17
D33
Q18
Q32
Q29
D26
D25
D27
D28
D31
Q33
Q35
Q34
Q36
Q31
Q30
Q25
D21
D100
D24
Q22
Q26
D37
D23
D22
D38
D40
D35
D36
D34
Q44
D1
R11
R29
R30
C13
R73
R75
W11
W24
C20
C23
VR2
C16
C17
C24
C25
IC2
C18
IC1
R45
R48
R51
W9
W10
W12
C19
S2
.
o
N
.
f
e
R
s
s
e
r
d
d
A
C
IQ
1C
3
2B
3
3F
2
4B
6
1D
3
2D
4
3C
4
4C
4
5C
4
6B
4
7C
4
8C
4
9C
3
0
1C
3
1
1B
4
2
1B
5
3
1B
3
4
1B
2
5
1C
4
6
1B
4
7
1F
2
8
1F
2
9
1F
2
0
2F
2
1
2D
3
2
2E
3
3
2D
3
4
2E
3
5
2E
3
6
2E
3
7
2B
6
8
2B
6
9
2G
2
0
3G
2
1
3G
2
2
3G
2
3
3G
4
4
3G
5
5
3G
4
6
3G
6
7
3E
6
8
3E
6
9
3D
5
0
4E
3
1
4B
6
4
4E
4
5
4D
5
6
4D
5
2SA1123
2SA733(A)
2SA817A
2SA965
2SA992
2SC1627A
2SC1845
2SC2235
2SC2631
2SC945(A)
E C
B
DTA124ESA
B C
E
2SC4137
EC
B
NJM4565D
1
4
5
8
UPC4574C
8
7
1
14
UPC494C
UPC1237HA
1
8
A
B
C
D
E
F
G
I
H
1
2
3
4
5
6
7
1
1
3
2
5
6
7
1
1
2
2
9
8
10
3
3
2
3
R8
1k
VR1
5k(A)
VR2
50k(C)
C15
0.047u
R36
10
R41
5.6k
13
12
14
2
3
4
1
5
6
8
7
S1
11
C16
10u
50v
C17
1u
50v
C18
1u
50v
C19
1u
50v
C20
10u
50v
C23
2.2u
50v
S2
C25
10u
50v
R61
4.7k
C22
22u
50v
R45
4.3k
R51
4.3k
C24
100p
C21
0.22u
R44
300
C11
1000p
50v
R25
2.2k
R26
2.2k
R13
150
R11
5.6k
R9
10k
R12
5.6k
R14
150
R28
30k
R29
7.5k
R30
12k
R31
150k
R32
120k
R33
6.8k
R35
10k
R16
1k
R10
10k
R15
68
C12
15p
C13
0.1u
50v
C14
0.1u
R37
10k
R38
20k
R40
36k
R39
36k
R43
24k
R52
22k
R175
100
R177
33k
R176
75k
R63
6.8k
C31
10u50v
R119
10
R115
22k
1/4w
R79
100
1/4w
(NB)
R80
10
1/4w
(NB)
R81
10
1/4w
(NB)
R83
10
1/4w
(NB)
R82
10
1/4w
(NB)
R78
100
1/4w
(NB)
R93
10
1/2w
R70
1k
1/2w
C37
220u
50v
C68
47u
25v
C66
47u
25v
C76
1u
50v
R184
75k
R182
33
R183
100k
R161
13k
R164
47k
R163
910
R165
10k
R167
10k
R168
33k
R162
180k
C71
10u
50v
C72
100u
10v
C73
1u
50v
C74
10u50v
R181
180k
R178
16k
R180
16k
R73
150
R88
4.7
(NB)
R86
4.7
(NB)
R19
1.5k
2w
R187
330k
R84
220
1/2w
(NB)
R85
4.7
(NB)
R89
0.1
2w
R105
620
C61
4700p
R106
620
R77
510
R102
1k
C62
4700p
C47
100p
50v
C38
12p
C40
1000p
50v
C39
270p
R67
2.2k
R65
1k
R62
47k
R186
10k
R47
4.3k
C32
470p
C34
47u
25v
R90
0.1
2w
R18
1.5k
2w
R20
1.5k
2w
R92
0.1
2w
R17
1.5k
2w
R91
0.1
2w
R169
1.2k
2w
R193
1.2k
2w
R103
1k
R104
1k
K1
R101
1k
R87
4.7
(NB)
R194
1k
CN3
VR3
220
R171
100k
R172
30k
R174
10
C75
1u50v
R111
2k
1/4w
R113
2k
1/4w
R117
10
C65
47u
25v
R173
2.7k
R170
33k
R75
6.8k
1/4w
R69
4.7k
1/4w
C36
270p
C35
15p
C33
0.01u
R64
100
R185
150k
R166
10k
R21
51k
R6
27k
R1
1k
R2
1k
R4
10k
R3
10k
R7
15k
R5
27k
C3
10u
50v
C2
1000p
C1
1000p
C5
100p
R23
51k
R157
2.2k
R229
2.2k
R228
2.2k
R131
10
1/2w
R132
10
1/2w
C53
2200p
C55
4700p
50v
C56
3900p
16v
R136
22
R137
22
R138
150
R139
150
IC1
IC2
IC3
IC4
:UPC4574C
:NJM4565D
:UPC494C
:UPC1237HA
Q1,2,16,25,26,41
Q3,4
Q5
Q6
Q7,8
Q9,10
Q11,12
Q13,14
Q15,24,27,28
Q17,19
Q18,20,39,44
Q21,22,29,32,37,38,45
Q23,30,31,46
Q33-36
Q40
:2SA992(F,E)
:2SC2631(Q,R)
:2SA1123(Q,R)
:2SC4137(V,W)
:2SC2235
:2SA965
:2SC5101LBV5
:2SA1909LBV5
:2SC1845(F,E)
:2SC1627A
:2SA817A
:2SC945(A)(Q,P)
:2SA733(A)(Q,P)
:IRFIZ48NLF24
:DTA124ESA
:1SS131
:RD20JS(B)
:FML22SVA
:IN5406-M
:RD16JS(B2)
:B30-1460-05
:FML22RVA
:RD7.5JS(B)
D1-4,6-23,27,28,32-34,37,38,40
D24
D25
D26
D29
D31
D35,36
D100
R143
470
R144
16k
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C59
47u 25v
C57
10u50v
R142 10k
C58
1000p
50v
R133
10
1/2w
R134
4.7k
R140
1.5k
R141
1.5k
R109
3.3k
R110
3.3k
R96
470
1/2w
R95
10
1/2w
C46
16v
1000u
R155
10k
R156
4.7k
R107
10k
R108
10k
R158
4.7k
R151
3.3k
R152
3.3k
7.5v
R153
3.3k
C70
10u
50v
C79
1000p
C69
10u
50v
R154
750
R226
10k
R188
100k
R227
10k
J5
CN4
SIGMA
+
-
SERVO
SP +
SP -
SIGMA
SERVO
L1
J4
J3
P-CON
+B
GND
C63
1000p
C64
1000p
C42
4700p
C43
2200p
C44
0.33u
C77
0.1u
R224
4.7
1/2w
R225
4.7
1/2w
FUSE
C78
0.1u
C45
0.33u
R135
4.7k
C54
2200p
L2
C52
3300u
50v
C51
3300u
50v
R22
51k
R24
51k
C7
2.2u
50v
C4
10u
50v
C9
2.2u
50v
C10
2.2u
50v
C8
2.2u
50v
CN2
E2
J2
CN1
E1
J1
Lch 1
Rch 2
R+
R-
L-
L+
12345678
TH1
TH2
R159
6.2k
R160
1k
1/2w
R66
1k
R116
22k
1/4w
R112
2k
1/4w
R120
10
R179
47k
R118
10
R114
2k
1/4w
R68
47k
C67
47u
25v
R74
6.8k
1/4w
R71
150
R72
150
C48
100p
R76
1.8k
R42
22k
R46
3.6k
R48
4.3k
R49
1.1k
R50
300
R34
4.7k
R27
30k
C6
15p
4
(X09-5320-10 A/3)
(X09 B/3)
RCA INPUT
(X09 C/3)
SPEAKER LEVEL INPUT
IC1
1/4
IC1
2/4
IC1
3/4
IC1
4/4
IC2 1/2
IC2
2/2
Q26
Q17
Q19
Q5
Q8
Q12
Q11
Q16
Q13
Q14
Q9
Q4
Q3
Q20
Q22
Q23
IC4
Q41
D40
D38
D25
Q36
Q35
Q33
Q34
Q32
IC3
Q27
Q28
Q39
D13
D18
D17
D19
D29
D30
Q38
Q37
Q45
Q46
D31
D20
D14
D15
D16
D32
D33
Q30
Q31
Q29
D28
D27
D26
Q40
D100
D34
Q18
D5
D36
D37
Q10
Q44
D7
D8
Q7
Q15
Q6
Q25
Q24
Q2
Q1
Q21
D1
D3
D4
D2
D23
D22
D21
D35
D6
D9
D11
D10
D12
D24
TEMPERATURE COMPENSATION
Q6
CLASS B
INITIAL STAGE
Q7-10
CLASS B FINAL
Q11-14
CURRENT
LIMITER
Q15,16
AVR
AVR
AVR
INPUT BUFFER
LPF
INFRASONIC FILTER
ISOLATE
IC1
PROTECTION IC
CLASS A INPUT DIFFERENTIAL AMPLIFIER
MID-V
O
VERLO
AD-IN
LA
TCH
A
C
OFF
IN
GND
RELA
Y
MUTE
Vcc
Q1,2
BASS BOAST
IC2
TWO-STAGE
DIFFERENTIAL
AMPLIFIER
CLASS A
Q3,4
MUTING CIRCUIT
Q21-23
ERRONEOUS
CONNECTION
PROTECTION CIRCUIT
AGAINST
Q24,25
CLASS A INITIAL STAGE CONSTANT-CURRENT CIRCUIT
Q26
S1
DC / DC CONVERTER DRIVE
NI.IN
I.IN
FB
DT
CT
RT
GND
C1
NI.IN
I.IN
R-OUT
CONT.
Vcc
C2
E2
E1
Q29-32
DC/DC CONVERTER
SWITCHING FET
P-CON INPUT
OVERCURRENT
PROTECTION
Q37
P-CON CONTROL
Q38,39
DISPLAY LED DRIVE
Q40
FINAL Tr. OVERCURRENT
DETECTION CONTROL
Q41
RELAY
DRIVE
DC/DC CONVERTER
CONTROL IC
IC3
Q33-Q36
Q44
ERRONEOUS
CONNECTION
PROTECTION CIRCUIT
AGAINST
Q27,28
CLASS A
CURRENT
MIRROR
CIRCUIT
Q5
INPUT SENSITIVITY
VR1
LPF FREQUENCY
VR2
INFRASONIC OFF -15-25
BASS BOOST OFF- 6-12
S2
0V
0V
15.5V
-15.5V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0.01V
-5V
0.65V
0.075V
15.5V
43V
43.5V
1.1V
0.57V
0.12V
0.57V
0.54V
0.54V
-0.56V
-0.56V
-0.6V
-0.6V
-0.13V
-0.75V
-43.5V
-1.1V
-2.1V
-0.53V
-15.5V
-43V
-43V
-45V
0V
45V
45V
2.1V
3.5V
14.3V
0.4V
14.4V
14.4V
14.4V
0V
3V
0.2V
1.7V
0V
3.7V
13.5V
5V
5V
13.5V
13.5V
5V
5V
5V
0V
0V
0V
0V
1.5V
0V
-1.1V
KAC-719
CAUTION:For continued safety, replace safety critical components only
with manufacturer's recommended parts (refer to, parts list).
Indicates
safety critical components. To reduce the risk of electric shock, leakage-
current or resistance measurements shall be carried out (exposed parts
are acceptably insulated from the supply circuit) before the appliance is
returned to the customer.
DC voltages are as measured with a high impedance voltmeter.Values may
vary slightly due to variations between individual instruments or/and units.
KAC-719
7
A
B
1
2
3
EXPLODED VIEW (UNIT)
Parts with exploded numbers larger than 700 are not suppied.