Sony XR-4890 (serv.man2) Service Manual ▷ View online
– 13 –
GUIDE (C)
2
guide (C)
1
three claws
MOUNTING POSITION OF CAPSTAN/REEL MOTOR (M901)
3
Capstan/reel motor(M901)
2
Two precision screws
(P 2
×
2)
1
Belt
30
°
– 14 –
SECTION 4
MECHANICAL ADJUSTMENTS
SECTION 5
ELECTRICAL ADJUSTMENTS
1. Clean the following parts with a denatured-alcohol-moistene
swab:
playback head pinch roller
rubber belt
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
Forward
CQ-403A
more than 90 g
(more than 3.18 oz)
Reverse
CQ-403R
more than 90 g
(more than 3.18 oz)
•
Tape Tension Measurement
0 dB=0.775 V
TAPE DECK SECTION
Tape Speed Adjustment
Setting:
Speed checker
Frequency counter
–1.5 to +2.5%
2,955 to 3,075 Hz
Procedure:
1. Put the set into the PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the
1. Put the set into the 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
Mode
Torque Meter
Meter Reading
Forward
CQ-102C
30 – 65 g•cm
(0.42 – 0.90 oz·inch)
Forward
CQ-102C
0.5 – 4.5 g•cm
Back Tension
(0.01 – 0.06 oz·inch)
Reverse
CQ-102RC
30 – 65 g•cm
(0.42 – 0.90 oz·inch)
Reverse
CA-102RC
0.5 – 4.5 g•cm
Back Tension
(0.01 – 0.06 oz·inch)
FF, REW
CQ-201B
60 – 200 g•cm
(0.83 – 2.78 oz·inch)
set
+
–
test tape
WS-48A
(3 kHz, 0 dB)
WS-48A
(3 kHz, 0 dB)
LINE OUT
10 k
Ω
speed checker
or
frequency counter
0 dB=1
µ
V
TUNER SECTION
The tuner section has no adjustment.
Adjustment Location:
– SET UPPER VIEW –
Tape Speed Adjustment
TU 1
– 15 –
– 16 –
IC331
TDA7462D
SE3L
SE3R
MUTE
SDA
SCL
PAUSE
OUT FL
OUT FR
OUT RL
OUT RR
SUBOUT+
SUBOUT–
VDD
GND
CREF
SE1L
SE1R
MD+
MD–
CDL+
CDL–
CDR–
CDR+
PDR
PDGND
PDL
SE2L
SE2R
INPUT
GAIN &
AUTO
ZERO
ZERO
PAUSE
DETECT
INPUT MUL
TIPLEXER &
MIXING ST
AGE
REAR SIDE
SELECTOR
FRONT SIDE
SELECTOR
LOUDNESS
CONTROL
CIRCUIT
INPUT
GAIN
BEEP
LOUDNESS
CONTROL
CIRCUIT
SOFT
MUTE
VOLUME
CONTROL
CIRCUIT
COMPANDER
TREBLE/
BASS
CONTROL
CIRCUIT
SUBWOOFER
OUT
FADER
SUBWOOFER
LP
IIC
BUS
DIGITAL CONTROL CIRCUIT
POWER
SUPPLY
FRONT
FADER
FRONT
FADER
REAR
FADER
REAR
FADER
VOICE BANDPASS
HP
LP
SDA
SCL
1
2
3
4
5
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
+
–
+
–
+
–
+
–
OVER VOLTAGE
PROTECT
REGULATOR
1
2 3 4
5
6
7
8
9
10
12
11
NC
MODE2
MODE1
STB
VDD
AMP
VCC
ANT
COM
AM
FM
GND
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
TA
B
PW
-GND
OUT2–
ST
-BY
OUT2+
Vcc1
OUT1–
PW
-GND1
OUT1+
SVR
IN1
IN2
S-GND
IN4
IN3
AC-GND
OUT3+
PW
-GND3
OUT3–
Vcc2
OUT4+
MUTE
OUT4–
PW
-GND4
DIAGNOSTICS OUT
IC661
BA3918-V2
IC751
TDA7385
• IC Block Diagrams – MAIN Board –
IC21
TB2118F (EL)
SECTION 6
DIAGRAMS
IC301
CXA2509AQ-T4
VDD
AMP
AMP
AMP
VDD2
1
2
3 4 5 6
7
8
9
10
24 23
22 21
20
19
18
17
16 15
11
12
14 13
XO
OSC
CE
DIN
CK
DOUT
SR
I/O-1
I/O-2
OUT-1
OUT-2
VDD2
IFC
VDD
FM IN
AM IN
D-GND
FM CP OUT
VT
AM CP OUT
VCC
REG
A-GND
XI
SERIAL
INTERFACE
I/O
PORT
OSCILLATOR
ON/OFF
BUFFER
REFERENCE
DIVIDER
PHASE
COMPARATOR
20BIT
IF COUNTER
PRESCALLER
12BIT
PROGRAMMABLE
COUNTER
+
–
REGULATOR
18BIT
18BIT
22BIT
40BIT SHIFT
REGISTER
REF
VCC
SEEK/RECP
SEEK/RECP
+
–
SIG
4BIT SWALLOW
COUNTER
OUTPUT
PORT
+
+
+
–
–
+
–
+
–
+
–
+ –
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
21
22
23
26
27
28
29
30
31
32
33
34
37
38
39
40
24
25
PBFB1
PBRIN1
PBREF1
PBFIN1
35
36
PBGND
VCT
PBFIN2
PBREF2
PBRIN2
PBFB2
PBEQ1
PBOUT1
VCC
TAPEIN1
AUXIN1
MSLPF
LINEOUT1
NC
NC
G2FB
G1FB
MSTC
DGND
MSOUT
NC
NC
INSW
TAPESW
MSMODE
DRSW
MSSW
NC
NC
LINEOUT2
DIREF
AUXIN2
TAPEIN2
PBEQ2
PBOUT2
GND
F2
120
µ
/70
µ
X1
X1
VCT
+
F1
120
µ
/70
µ
24dB
F3
LPF
VCC
DETECT
MS ON/
OFF
FWD/RVS
TAPE EQ
TAPE/AUX
NR BIAS
24dB
MS
MODE
T2
T1
1
2
2
3
4
5
6
7
8
9
10
VCC
IN2
S-GND
IN1
NC
NC
OUT2
NC
P-GND
OUT1
CONTROL
CIRCUIT
MOTOR
DRIVE
CIRCUIT
BUFFER
BUFFER
IC351
LB1930M-TLM
– 17 –
– 18 –
XR-4890/4900
6-1. PRINTED WIRING BOARD — MAIN SECTION —
Ref. No.
Location
• Semiconductor
Location
Noteon Printed Wiring Board:
• X
: parts extracted from the component side.
•
¢
: internal component.
D1
F-1
D51
E-11
D52
E-11
D351
I-12
D352
G-13
D501
J-5
D551
F-12
D552
F-12
D553
I-9
D554
F-12
D571
D-10
D572
D-10
D581
G-11
D588
E-9
D591
F-11
D601
J-13
D610
D-11
D611
D-11
D613
D-11
D614
C-11
D621
E-6
D622
E-7
D623
E-6
D624
E-7
D701
J-3
D702
K-3
D704
K-3
D705
K-5
D706
K-5
D707
K-5
D708
K-5
D709
K-5
D710
J-3
D711
K-5
D712
K-5
D713
K-5
D721
D-8
D722
D-8
D723
D-8
D724
D-9
D731
B-7
D732
D-7
D733
D-7
D734
B-7
D781
D-13
IC21
E-3
IC301
H-4
IC331
D-5
IC351
I-12
IC501
I-7
IC551
J-12
IC611
E-14
IC751
B-7
Q51
E-11
Q52
E-11
Q121
G-4
Q151
G-6
Q171
A-4
Q181
A-3
Q251
G-6
Q271
A-3
Q281
B-3
Q351
H-13
Q352
H-12
Q353
H-12
Q354
H-12
Q551
I-10
Q571
D-9
Q581
G-11
Q583
F-9
Q591
F-11
Q592
F-10
Q601
J-13
Q602
J-12
Q621
F-7
Q622
F-7
(Page 24)
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