background image
STEREO AUTO REVERSE CASSETTE DECK
X-SG7/SG7G
SERVICE MANUAL
© 1999-6/B51-5546-00 (K/K) 2299
70%
SYSTEM
CONTROL
REC
IN
PLAY
OUT
L
R
Phono jack
(E63-0046-15)
Metallic cabinet
(A01-3360-01)
Rectangular receptacle
(E08-0311-05)
Power cord bushing
(J42-0083-05)
AC power cord *
(E30-)
Refer to X-E9 and X-SA7 service manuals (B51-4926-00/B51-5214-00),
if you require in detail.
rev. mode
Dolby NR
CRLS
BC
1
0
2
7
3
¡
8
"
stereo auto reverse cassette deck
on/standby
front loading mechanism
Panel *
(A29-)
Panel *
(A60-)
Knob
(K29-6741-04)
Indicator
(B12-0319-13)
Knob
(K29-7572-13)
* Refer to parts list on page13.


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X-SG7/SG7G
2
ACCESSORIES
LED
ITEM
POWER
DOLBY B
DOLBY C
RVS
MODE
UNDER ADJUSTMENT
PB CALIB
ERR
L
R
PB LEVEL
ERR
L
R
REC CALIB
ERR
L
R
REC LEBEL
ERR
L
R
BIAS DAC
ERR
L
R
PB ALL OK
ALL OK
DISASSEMBLY FOR REPAIR
CIRCUIT DESCRIPTION
( Power does not turn on and tray does not come out.
1. Turn the pully in the direction of the arrow in the draw-
ing with a finger (
1).
2. If the tray comes out to the front side, pull out the tray
by hand forward the front (
2).
Audio cord (2)
(E30-0615-05)
System control cord (1)
(E30-2628-05)
V Correction of circuit description
LED indication state.
Operation to reset
The microcomputer may fall into malfunction
(impossibility to operate, erroneous display,
etc.) when the power cord is unplugged while
power is ON or due to an external factor. In this
case, execute the following procedure to reset
the microcomputer and return it to normal con-
dition.
Unplug the power cord from the power out-
let and, while holding the stop key de-
pressed, plug the power cord again.
÷ Please note that resetting the microcomputer
clears the contents stored in it returns it to con-
dition when it left the factory.


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X-SG7/SG7G
ADJUSTMENT
3
{
AC voltmeter
AC voltmeter
Oscilloscope
Distortion meter
AG
SYSTEM
CONTROL
REC
IN
PLAY
OUT
L
R
KSJ-0816
Order
Item
Input
setting
Output
setting
Deck
setting
Adjustment points
Adjustment method
Fig.
Unless otherwise specified, set the respective switches as follow :
TAPE : NORMAL
DOLBY : OFF
INPUT : REC IN
OUTPUT : PLAY OUT
I. Cassette mechanism section (Recording/play head adjustment)
< 1 >
Demagnetization
and cleaning
----
Power : OFF
Demagnetization,
cleaning, PLAY
Recording head,
erase head, capstan,
pinch roller
Demagnetize the REC/
PLAY head with the
head eraser. Clean the
REC/PLAY head, erase
head, capstan and
pinch roller using a
cotton swab slightly
damped with alcohol.
< 2 >
Azimuth of the
REC/PLAY head
TCC-153
MTT-114
10KHz, -10dB
LINE OUT
(Lch or Rch)
PLAY
Adjust the output to
maximum and adjust
the azimuth adjustment
screw for the Lissajous
waveform pattern of
the oscilloscope to
become close to a 45°
straight line.
II. Printed circuit board adjustment (X28-297)
(1)
Tape speed
(normal)
TCC-110
MTT-111
3KHz
(A)
PLAY
MOTOR VR.
Adjust so ; that the
frequency is 3KHz at
the tape center.
(2)
Playback level
TCC-130
400 Hz
(A)
MANUAL
ADJUSTMENT
MODE PLAY
ADJUSTMENT
VALUE
UP : [DOLBY] KEY
DOWN : [RVS
PLAY] KEY
CHANGE OF
ADJUSTMENT
MODE [CRLS] KEY
Output level : -1dBs
(3)
Bias current
TCC-108A
12.5KHz, -21dBm
(A)
MANUAL
TEST MODE
REC and PLAY
-21dBm
(4)
Recording level
TCC-108A
400Hz, -21dBm
(A)
MANUAL
TEST MODE
REC and PLAY
-21dBm
RVS
FWD
( The method of the manual adjust-
ment mode.
(1) Setting
Shorting the TEST pin of (X28-
)(A/5) TP5 --
w-- TP4 with the
diode, plug the power cord to the
AC wall let.
(2) Refer to manual adjustment
mode(3-3), if require more
details.
(A) Measurement Equipment Connection
G


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ACE
G
I
BD
F
H
J
2
1
3
5
7
4
6
E
B
1
64
41
24
80
65
40
25
1
1
10
1
6
13
BE
1
3
1
10
1
3
9
1
1
1
1
1
112
10
1
10
15
5
12
18
10
B
E
B
B
B
B
B
E
B
E
E
E
E
E
1
9
E
E
B
B
15
1
10
1
I
BE
B
E
B
E
G
O
REC IN
PLAY
OUT
SYSTEM
CONTROL
AC
OUTLET
E
B
E
B
E
B
E
E
B
E
E
B
B
B
B
E
B
E
B
EB
E
EB
E
B
E
B
E
B
E
B
EB
EB
E
B
E
E
E
E
B
B
B
B
Refer to the schematic diagram for the value of resistors and capacitors.
PC BOARD (Component side view)
4
5


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L
M
N
O
A
BD
F
H
CE
G
I
J
K
2
1
3
5
7
4
6
REC: 5.0V
OTHER: 0V
PLAY,REC,
REC PAUSE: 5.0V
OTHER: 0V
5.1V
5.1V
4.7V
4.8V
5.1V
11.3V
0.6V
5.7V
6.1V
12.3V
12.9V
4.7V
5.1V
0V
4.8V
0V
0V
0.6V
1.3V
1.3V
3.2V
3.5V
1.3V
1.3V
1.3V
1.3V
1.3V
1.3V
NORMAL:2.0V
METAL/CRO2:3.3V
STOP:4.4V
PLAY/REC:0V
REC: 0V
OTHER: 4.3V
1.2V
6.4V
REC:0V
6.4V
6.5V
1.7V
1.7V
6.5V
6.5V
6.5V
6.5V
6.3V
12.9V
6.5V
6.2V
6.4V
7.0V
7.0V
6.2V
6.2V 7.0V
6.4V
6.5V
6.5V
6.5V
6.5V
6.5V
1.7V
1.7V
6.5V
6.4V
REC:0V
6.4V
DOLBY OFF:0V
DOLBY ON:5.0V
DOLBY B:0V
DOLBY C:5.0V
PLAY:0V
REC:5.0V
OTHER:4.3V
REC:0V
CRO2/METAL:5.0V
NORMAL:0V
25.8V
5.1V
12.6V
12.9V
REC:4.8V
REC:0V
7.9V
7.3V
12.9V
9.8V
3.7V
1.3V
0.7V
3.7V
0.7V
1.3V
PLAY:12.9V
REC:0V
PLAY:0V
REC:5.0V
REC:4.4V
PLAY:0V
0.5V
0.8V
7.3V
0.6V
0.5V
0.8V
12.3V
12.3V
5.0V
11.6V
12.2V
PIN
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
11
12
10
PIN
NORMAL
CRO2
METAL
METAL
CRO2
NORMAL
1.9V
4.4V
3.2V
4.4V
2.4V
1.9V
2.6V
4.1V
3.2V
3.6V
12.9V
0V
12.9V
1.8V
2.9V
4.38V
2.3V
3.4V
1.7V
2.9V
2.64V
4.1V
12.9V
1.69V
MODE:RECORDING
IC8 VOLTAGE
7.0V
10u16
C229
+
C239
1u50
+
22u16
C209
+
C210
22u16
+
10u16
C233
+
10u16
C232
+
22u16
C234
+
C238
100u16
+
47u16
C21
+
C214
1u50
+
1u50
C114
+
C122
0.1u50
+
C124
0.1u50
+
C126
10u16
+
C130
0.1u50
+
C132
2.2u50
+
+
C131
2.2u50
C125
10u16
C121
0.1u50
++
1u50
C113
+
C123
0.1u50
+
C129
0.1u50
+
+
+
+
+
+
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
)
(
(
)
)
(
(
)
(
)
)
(
)
(
)
(
)
(
)
(
)
(
)
(
C158
22u35
+
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
(
)
)
)
(
)
(
)
(
)
(
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
1u50
C23
+
1u50
C24
+
C14
1u50
+
10u16
C8
+
C9
100u10
+
100u16
C5
+
)
(
)
(
)
(
(
)
)
(
)
(
)
(
)
(
(
)
)
(
(
)
)
(
(
)
)
(
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
)
(
(
)
)
(
18
17
16
15
14
13
12
10
PROTECTIONCIRCUIT
THARMALDETECTING
POWERSOURCE
STABILIZING
+15V
DET.
ABSO.
DET.
PEAK
DET.
ABSO.
1
2
3
DET.
PEAK
4
VCA
11
DRIVER
PRE
7
VCA
COMPARATOR
5
6
GND
8
9
0.022
C225
220K
R219
0.01
C221
0.022
C227
R221
33K
C223
560P
33K
C228
0.022
0.022
C226
C222
0.01
220K
R220
C224
560P
R222
C230
10P
1
2
3
4
5
6
4
1
2
3
HX
L4
150P
C218
220P
C220
1
6
220P
4
C219
3
2
L3
EH
C217
150P
EH
4
6
L9
3
1
2
5
C231
0.01
0.01
C237
22K
R226
10
1/4W
R224
10
R223
1/4W
5600P
C236
R225
22K
C235
5600P
68
R233
4.7K
R235
K1
150K
R207
390P
C205
10u16
C203
+
R205
160
R203
0.022
C207
6.2K
1
2
4
3
5
160
R204
6.2K
R206
150K
R208
390P
C206
7
8
9
6
0.022
C208
10u16
C204
+
C201
680P
R201
150K
C202
680P
R202
150K
Q31,32
10mH
L7
220P
C215
15K
R211
15K
R212
10mH
220P
C216
L8
Q44
10K
R214
10K
R213
1K
R229
10
R230
22K
R227
10
R234
R228
5.6K
1/4W
1/4W
10
9
8
7
6
5
4
3
2
1
11
12
R218
1K
R217
1K
R216
10K
R215
10K
3.3K
R231
1K
R232
Q47,48
12 11
8
9
10
7
6
5
4
1
32
PLAY/REC
PLAY
Lch
GND
PLAY
Rch
REC
Lch
REC
Rch
BIAS
Rch
BIAS
Lch
BIAS
ERASE
EH
GND
13V
1
2
3
4
5
6
GND
1
OUT1
2
Vz1
3
Vref
4
Fin
5
Rin
6
Vcc1
7
Vcc2
8
Vz2
9
OUT2
10
C20
0.1
10
R45
C18
0.1
R44 1K
R42
1K
R43
1K
1/4W
1
2
3
45
R109
3.9K
C107
6800P
NC
L1 MPX
1.5K
R107
R158 18K
56
E. VOL
E. VOL
71
1
80
VREF
77
78
79
1A
3
2
5
4
REF
VR3
VR2
74
75
76
VR1
GND
72
73
DAC
SBIT
67
GND
VR1
68
69
70
VR2
VR3
BIAS
65
66
DAC
SBIT
64
63
1A
VREF
60
62
61
58
59
57
REC
OUT
8
7
6
10
9
B/C NR
DOLBY
12
11
IREF
13
14
VOL
RECT
EQ
LMA
+
­
SBIT
DAC
EQ
REC
EQ-CONTROLER
NN
NC
17
16
15
NM
HN
HC
20
19
18
21
HM
22
23
24
GH
GL
GP
DAC
SBIT
25
26
27
FM
FQ
F/Q
28
29
30
BIAS
VCC
­
+
LMA
DAC
SBIT
REC
OUT
B/C NR
DOLBY
54
55
51
52
53
RECT
EQ
REC
VOL
EQ
49
50
47
48
ADJ.
BIAS
DAC
SBIT
31
32
VCC
BIAS
33
34
35
36
GND
N
M
CONT
RESET
MPX
SW
C/B
ON/OFF
44
45
46
43
42
37
38
C
39
40
41
LOGIC
ILL
C103
10u16
+
1u50
C105
+
R103
33K
1u50
C143
+
+
1u50
C154
+
C104
10u16
+
C106
1u50
+
C144
1u50
1.5K
R108
6800P
C108
32
1
4
R110
5
L2
NC
MPX
3.9K
39K
R105
39K
R106
R104
33K
C213
1u50
+
3300P
C211
3300P
C212
1.5K
1.5K
C118
2200P
C116
2200P
22K
R114
0.033
C112
220P
R112
2.2K
10mH
L6
R116
560
C110
C120
2200P
R126
10K
R130
R128
4.7K
C134
1u50
+
R159
24K
C136
2.2u50
22K
R120
4.7K
R118
2.2u50
C128
+
1.1K
R122
R124 1K
R145
120K
R139
47K
GP
R140
R146
51K
36K
GL
R141
R147
56K
30K
GH
R142
R148
68K
56K
F/Q
R143
R149
43K
56K
FQ
R144
R150
220K
220K
FM
NC
NN
R127
4.7K
C133
1u50
R125
10K
C119
2200P
C115
2200P
C117
2200P
R115
560
C127
R121
4.7K
R117
R119
22K
1.1K
2.2u50
+
C111
C109
0.033
220P
R123 1K
47K
22K
R113
R111
2.2K
10mH
L5
C155
1u50
C156
1u50
C157
1u50
2.2u50
C135
+
C141 18P
C138 1u50
+
R132 100K
C137 1u50
+
R131 100K
R151 100K
R152 62K
R157 3.9K
C139 18P
R154 5.6K
R153 5.6K
C140 56P
R155 5.6K
C142 100P
R156 1K
29
32
39
40
41
42
46
50
3300P
R161
6.2K
0.1
12K
1.2K
R163
C146
R162
C145
47K
R160 120K
R164 22K
1
2
3
4
5
6
7
8
9
10
15
14
13
12
11
R210
R209
1
2
3
4
5
6
7
8
9
10
1
3
4
14
13
50
46
42
41
40
39
32
29
6
3
1
2
5
4
6
8
7
10
9
2
1
3
4
5
8
7
9
11
10
13
12
14
15
REC. R
MUTE +B
BIAS. R
13V
BIAS. L
CLK
DATA
ST
RESET
REC. L
LEV. L
5V
S. BUSY
S. DATA
D. GND
A. GND
PLAY. R
120/70
400/12.5k
PLAY. L
OSC ATT
OSC
LINE MUTE
REC MUTE
LEV. R
220P
C102
220P
C101
100
R102
100
R101
220P
220P
C150
C149
1.2K
R133
4.7K
R137
4.7K
R138
1.2K
R134
R136
56K
R135
56K
0.01
C148
100K
R168
100K
R167
220P
C152
220P
C151
R169
56K
R166
10K
R165
10K
13
14
1
4
3
REC
MUTE
LINE
MUTE
1
2
3
4
5
6
7
8
9
10
13
11
12
47K
R7
4.7K
R8
3.3K
R10
47K
R9
40
41
R6 100
R5 100
R3 100
R1 100
47K
R54
R2 100
100
R41
R40
100
65
64
67
66
CLOSE
SOL
64
OPEN
CASS.
SW
Fin
R.
INH
A
Rin
READ
AVSS
CE
TEX
NC
TX
NC
73
VSS
VDD
72
A
33
71
34
70
35
69
36
68
37
67
38
66
39
65
40
DATA
63
CLK
62
PH SW
61
NC
60
OSC OUT
59
NC
58
GND
57
GND
56
GND
55
GND
54
NC
53
STB
52
DATA
51
PLAY/REC
50
BIAS
49
CLK SYSTEM IC
48
ERASE
47
PLAY SW
46
LEVEL. R
45
LEVEL. L
44
R. INH B
43
I/I
42
CPM
41
E2 PROM
SYSTEM IC
65
66
67
R39 10K
41
R55 47K
42
43
44
45
46
47
48
49
50
51
52
R56 47K
R53
47K
R51
47K
40
38
39
59
R59 10K
15K
R52
1u50
C13
+
R38
100K
10K
R37
1K
R46
0.022
C27
1K
R27
1.5K
R26
GND
OUT IN
R22
100
1/4W
+
10u16
C4
4
VSS
DATA
A2
3
CLK
A0
A1
2
VCC
NC
1
5
6
7
8
C12 0.01
R35
22K
R33
1K
22K
R34
R29 100K
330
R32
330
R31
R30 100K
GND
S.DATA
S.BUSY
S.GND
78
77
76
59
75
74
45
44
52
51
48
61
62
63
47K
R58
47K
R57
64
43
42
46
61
38
39
50
49
47
63
R36
1K
62
1
80
REC F
HALL OUT
SOL
HALF
GND
12V
MOTOR +
MOTOR ­
COM
MODE
CrO2
METAL
REC R
OPEN
CLOSE
COM
MOTOR ­
MOTOR +
EH
Lch
Rch
GND
EH GND
+ERASE
(BRN)
+E (BRN)
-E (BLU)
+R (GRN)
-L (ORG)
+L (RED)
Lch
Rch
+12V
GND
(BLU)
-ERASE
-Rch
(YEL)
+Rch
(GRN)
(RED)
+Lch
-Lch
(ORG)
EARTH
(WHT)
-R (YEL)
GND (WHT)
1
2
3
4
5
EH
EH GND
Rch
Lch
GND
1
2
3
4
5
6
7
8
9
10
13
11
12
2
1
Rch
Lch
6
5
4
3
CLOSE
OPEN
COM
MOTOR -(CCW)
MOTOR +(CW)
FEW REC
HALL OUT
SOL
HALF
GND
12V
MOTOR +(CW)
MOTOR ­(CCW)
COM
MODE
CrO2
METAL
REV REC
1.2K 1W
R173
1.2K 1W
R172
R171
1.2K 1W
R129
C147
+
100u16
47K
R48
0.01
C10
C19 0.01
DOLBY
HX PRO
ERASE OSC
Q45
Q46
D33
Q44
Q33
Q31
Q32
IC7
(1/2)
(2/2)
IC7
PLAY
MUTE
PB EQ
RELAY SELECT.
PLAY/REC
D32
Q41
Q43
Q42
EH CONT.
Q48
Q47
CONT.
BIAS
CN12
CN11
CN5
D18
D20
CN6
Q24
Q23
Q27
Q28
Q29
Q30
1
2
3
4
Lch
Rch
REC
PLAY
Rch
Lch
Q21
Q22
MUTE
D24
D23
Q25
Q26
D22
D10
D21
J2
J3
CPM
CONT.
Q6
Q8
CONT.
SOLENOID
Q7
Q9
D8
D9
Q11
Q12
Q10
RESET
D17
Q3
D4
D19
u-COM
5V
AVR
RESET
D2
D3
Q5
13V AVR
E2ROM
D12
D11
D13
D14
D16
D15
SYSTEM
CONTROL
CN10
CN4
MOTOR
DRIVE
CN2
CN3
CN9
Lch
ERASE
HEAD
R/P HEAD
Rch
PHOTO REFLECTOR
MOTOR
S6
S5
S4
S3
S2
S1
SOL
TRAY
MOTOR
S8
S7
Lch
Rch
(BOTTOM VIEW)
IC8
(X28-2972-71) (C/5)
IC6
IC1
IC3
IC4
(X28- ) (B/5)
(X28­ ) (A/5)
R/P/E HEAD
HEAD PCB
MECHANISM (D40­1574 ­15)
IC2
R254 1K
CAUTION: For continued safety, replace safety critical components only with manufacturer's recommended parts (refer to
parts list).
indicates safety critical components. For continued protection against risk of fire, replace only with same type
and rating fuse(s). 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.
The DC voltage is an actual reading measured with a high impedance type voltmeter with a cassette loaded
at playback mode. The measurement value may vary depending on the measuring instruments used or on
the product. Bias circuit DC voltage is measured while in the record mode.
DOLBY and the double-D symbol are trademarks of Dolby Laboratories
Licensing Corporation. Noise reduction circuit made under license from
Dolby Laboratories Licensing Corporation.