Sony XR-4950X Service Manual ▷ View online
XR-4950X
13
3-6.
GUIDE (C)
3-7.
MOUNTING POSITION OF CAPSTAN/REEL MOTOR (M901)
2
guide (C)
1
three claws
two precision screws
(P2
(P2
×
2)
Note: Mount the motor so that the
angle between of the
motor and the hole for the
screw becomes 30
motor and the hole for the
screw becomes 30
°
as
shown in this figure.
capstan/reel motor
(M901)
(M901)
30˚
14
XR-4950X
Procedure:
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the
reading on the frequency counter becomes 3,000 Hz.
Specification: Constant speed
Adjustment Location:
Tape Speed Adjustment
– SET UPPER VIEW –
SECTION 4
MECHANICAL ADJUSTMENTS
• Tape Tension Measurement
1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head
pinch roller
rubber belt
capstan
idler
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the power supply
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the power supply
voltage (14.4 V) unless otherwise noted.
• Torque Measurement
Mode
Torque Meter
Meter Reading
2.95 – 6.37 mN•m
Forward
CQ-102C
(30 – 65 g•cm)
(0.42 – 0.90 oz•inch)
Forward
0.05 – 0.44 mN•m
CQ-102C
(0.5 – 4.5g•cm)
Back Tension
(0.01 – 0.06 oz•inch)
2.95 – 6.37 mN•m
Reverse
CQ-102RC
(30 – 65 g•cm)
(0.42 – 0.90 oz•inch)
Reverse
0.05 – 0.44 mN•m
CQ-102RC
(0.5 – 4.5g•cm)
Back Tension
(0.01 – 0.06 oz•inch)
5.89 – 19.61 mN•m
FF, REW
CQ-201B
(60 – 200 g•cm)
(0.83 – 2.78 oz•inch)
Mode
Tension Meter
Meter Reading
Forward
CQ-403A
more than 60 g
(more than 2.12 oz)
Reverse
CQ-403R
more than 60 g
(more than 2.12 oz)
SECTION 5
ELECTRICAL ADJUSTMENTS
0 dB=0.775 V
Tape Speed Adjustment
Setting:
Frequency counter
2,955 to 3,075 Hz
TAPE DECK SECTION
frequency counter
test tape
WS-48A
(3 kHz, 0 dB)
WS-48A
(3 kHz, 0 dB)
set
AUDIO OUT REAR jack (J331)
–
+
10 k
Ω
TUNER SECTION
Tuner section adjustments are done automatically in this set.
15
XR-4950X
SECTION 6
DIAGRAMS
6-1.
NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
C
: panel designation.
•
A
: B+ Line.
• Power voltage is dc 14.4V and fed with regulated dc power
supply from ACC and BATT cords.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
(
no mark : FM
(
) : MW/LW
<
> : TAPE PLAYBACK
∗
: Impossible to measure
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: FM
f
: MW/LW
E
: TAPE PLAYBACK
Note on Printed Wiring Board:
•
•
X
: parts extracted from the component side.
•
Y
: parts extracted from the conductor side.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side:
Pattern face side:
Parts on the pattern face side seen from
(Conductor Side)
the pattern face are indicated.
Parts face side:
Parts on the parts face side seen from
(Component Side)
the parts face are indicated.
2.2 Vp-p
30.5
µ
s
1.1 Vp-p
54.2 ns
• Waveforms
– MAIN Board –
– MAIN Board –
1
IC501
qd
(OSCIN)
2
IC501
qg
(XIN)
– KEY Board –
1
IC901
y;
(OSC)
2.7 Vp-p
27
µ
s
XR-4950X
17
17
6-2.
PRINTED WIRING BOARD – MAIN Board –
CN351
S551
X501
C781
CN781
C301
C356
C
354
C617
C616
C615
D352
C302
C551
C355
C501
R573
D610
C614
C611
C612
D781
C571
R352
C335
JW1
D588
D611
L501
R535
R601
R631
JW4
JW5
JW6
JW7
JW8
JW9
JW12
JW13
JW14
JW15
JW17
JW18
JW19
JW20
JW21
JW22
JW24
JW25
JW26
JW27
JW28
JW29
JW30
JW31
JW32
JW33
JW40
JW41
JW43
JW44
JW46
JW47
JW48
JW49
JW50
JW51
JW54
JW56
JW57
JW59
JW60
JW61
JW62
JW63
JW68
JW70
JW71
JW72
JW74
JW75
JW76
JW77
JW78
JW79
JW80
JW86
JW87
JW88
JW89
JW90
JW94
JW95
JW
96
JW
97
JW98
JW99
JW100
JW104
JW105
JW106
JW107
JW108
JW109
JW110
JW112
JW201
JW202
IC611
D701 D702
R632
JW114
C622
C3
C337
JW115
JW116
JW117
JW118
JW53
JW34
JW35
JW36
JW37
JW38
JW39
JW111
JW42
JW10
JW11
JW64
JW65
JW66
JW67
JW69
J331
CN701
JW113
JW119
Q601
JW45
S552
D613
D614
X502
JW73
JW103
JW102
JW92
JW93
JW120
JW16
JW91
L51
JW2
JW52
JW23
C52
C552
C755
JW101
PO1
R625
D722
C6
Q354
R303
C304
C201
C202
C102
IC301
R538
C
504
C503
C506
C505
R523
Q621
D621
Q352
R351
D351
JC351
D601
C602
C601
Q602
C358
R302
C553
R551
R101
C206
C204
R203
R204
R202
C203
R306
D622
R521
R520
C205
C306
C305
R304
D501
R554
R556 R555
R703
R704
R705
Q551
D553
Q581
D572
D571
R572
R571
Q571
C1
C303
C105
R301
C174
Q171
R702
D708
R353
Q353
R354
C352
C357
C351
C353
D581
IC551
C191
R192
C621
R305
C307
C104
JC304
JC301
JC303
R574
R548
R563
R586
R588
R589
R544
R558
C502
R541
R561
R562
C556
R542
C508
R587
Q583
R519
R518
R201
R103
C103
R104
R102
R517
C2
R545
R1
R2
R510
R191
R507
C5
R546
R540
R514
R621
C336
R171
R175
R172
R181
Q181
R185
R182
C184
C182
R271
R275
Q271
R272
C274
C272
R281
Q281
R285
R282
C284
C282
R594
JC503
IC331
R604
R603
R21
R11
R12
R22
C23
R564
R333 R334
C331
C13 R332
C340
R331
C785
D51
JC502
C758
D709 D707
Q631
D705
R553
JC302
JC504
C509
D703 D704
JC507
R526
R527 R528
R529
R530
R552
R503
R501
R547
R557
C333
C21
C22
C11
R708 R706 R707 R710
R781
R782
C582
D1
R753
C101
R543
C106
D706
Q351
R508
R509
R502
R512
R513
R511
IC351
JC191
C511
C341
R570
JC171
JC181
JC271
JC282
JC281
JC283
JC193
JC194
JC195
JC51
R576
R751
C41
R537
R536
R539
R590
Q592
Q591
D591 R581
R593
R592
R591
C109
C111
C209 C211
C210
C110
C112
C212
R283
R183
R273
R173
C8
C332
R500
C44
JC192
C702
C703
C183
C283
C172
C753
C756
C752
C783
C784
C782
C618
C623
C271
C171
C281
C181
Q622
D625
R624
D551
IC501
IC751
24
2
25
1
L781
MAIN BOARD
J1
(FM/AM ANTENNA)
TU1
(FM/AM TUNER UNIT)
AUDIO OUT
REAR
J331
(REMOTE IN)
1-676-600-
12
SUB BOARD
CN301
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
A
B
C
D
E
F
G
H
I
J
K
L
M
1
19
MECHANISM
BLOCK
RESET
NOSE
DETECT
1
2
3
D1
F-9
D51
F-13
D351
J-13
D352
H-13
D501
K-8
D551
G-13
D553
K-10
D571
E-10
D572
E-10
D581
G-12
D588
F-10
D591
G-12
D601
K-14
D610
F-11
D611
F-10
D613
E-11
D614
E-11
D621
F-7
D622
E-8
D625
E-8
D701
L-5
D702
L-5
D703
L-6
D704
L-6
D705
K-4
D706
L-6
D707
K-4
D708
K-3
D709
K-4
D722
E-9
D781
E-13
IC301
I-5
IC331
F-5
IC351
J-14
IC501
I-9
IC551
L-11
IC611
F-14
IC751
C-8
Q171
D-5
Q181
D-5
Q271
D-6
Q281
E-6
Q351
I-13
Q352
J-13
Q353
I-13
Q354
H-13
Q551
J-12
Q571
E-9
Q581
F-12
Q583
F-9
Q591
G-12
Q592
G-12
Q601
K-14
Q602
K-14
Q621
F-7
Q622
F-8
Q631
M-6
• Semiconductor
Location
Ref. No.
Location
(Page 20)
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