Sony XR-4950X / XR-4954X Service Manual ▷ View online
XR-4950X/4954X
17
17
SECTION 5
MECHANICAL ADJUSTMENTS
SECTION 6
ELECTRICAL ADJUSTMENTS
1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head
pinch roller
rubber belt
capstan
idlers
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the power supply
voltage unless otherwise noted.
•
Torque Measurement
Mode
Tension Meter
Meter Reading
more than 0.88N
Forward
CQ-403A
more than 90 g
(more than 3.18 oz)
more than 0.88N
Reverse
CQ-403R
more than 90 g
(more than 3.18 oz)
•
Tape Tension Measurement
Mode
Torque Meter
Meter Reading
2.95 – 6.37 N•m
Forward
CQ-102C
30 – 65 g•cm
(0.42 – 0.90 oz•inch)
Forward
0.05 – 0.44 N•m
Back Tension
CQ-102C
0.5 – 4.5 g•cm
(0.01 – 0.06 oz•inch)
2.95 – 6.37 N•m
Reverse
CQ-102RC
30 – 65 g•cm
(0.42 – 0.90 oz•inch)
Reverse
0.05 – 0.044 N•m
Back Tension
CQ-102RC
0.5 – 4.5 g•cm
(0.01 - 0.06 oz•inch)
5.89 – 19.61N•m
FF, REW
CQ-201B
60 – 200 g•cm
(0.83 – 2.78 oz•inch)
6-1. TEST MODE
<Set the Test Mode>
1. Set the “OFF” mode.
2. Push the preset
1. Set the “OFF” mode.
2. Push the preset
[4]
button.
3. Push the preset
[5]
button.
4. Press the preset
[1]
button for more than two seconds.
5. Then the display indicates all lights, the test mode is set.
<Release the Test mode>
1. Push the [OFF] button.
1. Push the [OFF] button.
0 dB=0.775 V
Speed checker
Frequency counter
–1.5 to +2.5%
2,955 to 3,075 Hz
TAPE DECK SECTION
set
+
–
test tape
WS-48A
(3 kHz, 0 dB)
WS-48A
(3 kHz, 0 dB)
AUDIO OUT jack (J331)
10 k
Ω
speed checker
or
frequency counter
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 speed checker or frequency counter becomes in
specification.
specification.
Specification: Constant speed
TUNER SECTION
0 dB=1 µV
The tuner section has no adjustment.
Adjustment Location:
– SET UPPER VIEW –
Tape Speed Adjustment
Tape Speed Adjustment
Setting:
XR-4950X/4954X
18
18
7-1.
BLOCK DIAGRAMS – TUNER/TAPE/MAIN SECTION –
SECTION 7
DIAGRAMS
09
TAPEEQUALIZER METAL, AMS, DOLBY
IC301
37
39
R-CH
PBF
IN2
IN2
FWD
L-CH
HP901
(PLAYBACK)
FWD
R-CH
REV
L-CH
REV
R-CH
PBR
IN2
IN2
R-CH
R-CH
R-CH
R-CH
R-CH
R-CH
EQ AMP
2
4
MUTE
DOLBY
NR AMP
PB
OUT2
TAPE
IN2
IN2
AMS
DET
+
NROUT
19
DRSW
18
TAPESW
17
16
20
INSW
TAPE ATT
DOLBY
AMSON
AMSIN
MSSW
7
LINE
OUT2
14
MS
OUT
SE1L
MPX
AM DET
SE2L
SDA
SCL
EXT-AT
13
1
11
12
4
VOLUME
CONTROL
CIRCUIT
LOUDNESS
CONTROL
CIRCUIT
DIGITAL CONTROL
CIRCUIT
IIC BUS
LOUDNESS
CONTROL
CIRCUIT
INPUT
SELECTOR
AM IF
INPUT SELECT,
ELECTRICAL VOLUME
STEREO DECODER
IC331
SOFT
MUTE
TONE
CONTROL
CIRCUIT
FADER
FADER
29
18
20 21
OUT LR
30
OUT LF
DATA
CLOCK
MASTER MICRO COMPUTER
IC501 (2/3)
46
VOL ATT
47
I2C CKO
45
I2C SIO
BEEP
J331
AUDIO OUT
(REAR)
L
R
15
TEST
49
AMP ATT
40
TELATT
50
ATT
MUTE DRIVE
Q621
MUTING
CONTROL SWITCH
Q622
AMP ON
BATT B+
D622
D588
D621
FRONT L (+)
1
AUX
12
14
5
3
FL+
FL–
21
23
FR+
FR–
FL-IN
FR-IN
11
9
7
RL+
RL–
RL-IN
15
22
17
19
RR+
RR–
RR-IN
4
TEL MUTE
Q583
CN781 (1/2)
(POWER CONNECTOR)
POWER AMP
IC751
FRONT L (–)
9
FRONT R (+)
4
FRONT R (–)
12
REAR L (+)
2
REAR L (–)
10
REAR R (+)
3
REAR R (–)
11
13
MUTING
Q171
MUTING
Q271
MUTING
Q181
STNBY
MUTE
MUTING
Q281
R-CH
R-CH
CAPSTAN/REEL
MOTOR DRIVE
Q354
CMON
BATT B+
M
M901
CAPSTAN/REEL
MOTOR
TAPE REG DRIVE
Q352
LMEJ
TAPON
LMLOD
VCC
+B (8.5V)
BATT B+
IN2
IN1
OUT2
OUT1
LOADING MOTOR DRIVE
IC351
M
7
9
MOTOR
DRIVE
4
3
1
TAPE REGULATOR
Q351
LOADING/TAPE
OPERATION
MOTOR
TESTIN
39
TAPE OPERATION
SWITCH
BUFFER
TAKE-UP
REEL
SENSOR
SUPPLY
REEL
SENSOR
REEL SENSOR BOARD
REEL
85 – 88
POS0 – POS3
TAPE
DETECT
EJECT/FF/REW/
REV/FWD MODE DETECT
TEL
• SIGNAL PATH
: MW(SW)
: FM
: TAPE PLAYBACK
53
91
90
89
92
52
57
55
48
84
MECHANISM BLOCK
MOTOR DRIVE
SWITCH
Q353
16
35
1
4
2
FM-ANT
AM-ANT
14
S-METER
17
SDA-FEP
SCL
7
3
77
SW SHIFT
18
SCL-FEP
TU ATT
SW SHIFT
VSM
2
E2P SIO
74
75
E2P CKO
10
8
13
MPX
AM DET
12
MASTER MICRO COMPUTER
IC501 (1/3)
FM/AM TUNER
TU1
MUTING
Q11
MUTING CONTROL
SWITCH
Q31
MUTING
Q21
FM AGC
SDA
FM AGC
J1
(FM/AM ANTENNA)
11
BU+B
TU5V
TU8V
EEP VDD
10
VDD
5
VCC
19
AM IF
51
D31
XR-4950X/4954X
19
19
– DISPLAY/KEY CONTROL/BUS CONTROL/POWER SUPPLY SECTION –
MASTER MICRO COMPUTER
IC501 (3/3)
82
RE-IN1
KEYACK
26
KEYIN1
RE-IN0
81
80
KEYIN0
RC-IN0
RC-IN1
5
4
7
24
KEY ON
SWITCH
Q551
D501
ENCODE –
ENCODE +
D533
AD-ON
S901 – 904
LSW901 – 904,
906, 907, 909
ROTARY
ENCODER
RE901
BU+B
(VOLUME)
RE901
J561
REMOTE IN
DOORSW
78
CN901
(FRONT PANEL SIDE)
CN701
(MAIN UNIT SIDE)
1
9
OSCOUT
OSCIN
XOUT
XIN
12
13
16
15
X501
18.432MHz
X502
32.768kHz
LSW901 – 904, 906, 907, 909
LSW912 – 917
LSW912 – 917
LED901 – 904
DI
64
CL
63
60
CE
OSC
62
LCD SO
CLK-LCD
CE-LCD
DATA-LCD
13
LCD CKO 14
16
LCD CE
FP+B
FP+B
LIQUID CRYSTAL DISPLAY DRIVER
IC901
4
–
51
S04
–
S51
52
–
55
COM1
–
COM4
LIQUID CRYSTAL DISPLAY
LCD901
09
BU+B
RESET
IC551
BATTERY CHECK
Q581
BATT B+
BUIN
BUIN
28
BUIN
33
D581
RESET
S551
(RESET)
DSTSEL
6
ANT+B
TU+B (8V)
REGULATOR
IC611
COM8V
TU+B (5V)
TUNER 5.6
TUNER 8.7
STB
18
BATT
ANT REM
6
CN781 (2/2)
(POWER CONNECTOR)
COM +8V
(AUDIO CIRCUIT B+)
D572
TU5V
FM/AM TUNER UNIT
TU8V
VCC
7
7
ACC
DOOR
INDICATOR
SWITCH
Q631
DOOR IND 79
LSW801
LED801
FP REGULATOR
DRIVE
Q602
ACCESSORY
CHECK
Q571
FP REGULATOR
Q601
FP B+
2
3
4
9
BU+B
BU +B
D551
5
10
11
8
AMP+B
6
TUON
PWON
83
ILL-ON
34
36
BATT B+
POWER AMP
(IC751) B+
AMP REM
5
D610
D611
38
ACC IN
XR-C4950X
XR-C4954X
S501
(FREQUENCY SELECT)
LSW801
NOSESW
18
(NOSE SW)
S552
BACK UP
LED910 – 914
(LCD BACK LIGHT)
NON BUS SWITCH
Q591, 592
BU+B
BATT+B
9 kHz
10kHz
R560
47k
BU+B
BU+B
BU+B
R531
22k
XR-4950X/4954X
20
20
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
For schematic diagrams.
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
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.
•
U
: 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
( ) : MW (SW)
< > : TAPE PLAYBACK
no mark: FM
( ) : MW (SW)
< > : 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.
• Signal path.
F
: FM
f
: MW (SW)
E
: TAPE PLAYBACK
For printed wiring boards.
Note:
• X
: parts extracted from the component side.
• Y
: parts extracted from the conductor side.
• b
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Parts on the pattern face side seen from the
(Conductor Side) pattern face are indicated.
Parts face side:
Pattern face side: Parts on the pattern face side seen from the
(Conductor Side) pattern face are indicated.
Parts face side:
Parts on the parts face side seen from the
(Component Side ) parts face are indicated.
1
2
WAVEFORMS
– MAIN BOARD –
– MAIN BOARD –
IC501
qd
(OSC IN)
IC501
qg
(X IN)
30.5
µ
sec
2.2Vp-p
0.58
µ
sec
1.1Vp-p
1
– KEY BOARD –
IC901
y;
(OSC)
27
µ
sec
2.7Vp-p
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