Sony TCM-900DV Service Manual ▷ View online
TCM-900DV
6
3-2. ELECTRICAL ADJUSTMENTS
• Standard Level
Input signal level
MIC
– 60dBs
Output signal level
EAR (EARPHONE)
1.6k
Ω, –22,4dBs
• Test Tape
Type
Signal
Used for
WS-48A
3kHz, 0dB
tape speed adjustment
0dB=0.775V
Setting :
Setting :
VOL Control (RV301)
: mechanical mid
REC TIME (S903)
: normal(4.8cm/s)
SPEED CONTROL (RV901): normal (center click)
DPC(MANUAL) Adjustment
Setting :
DPC(S904) switch
: MANUAL
Tape speed
: 4.8cm/s
Mode
: PLAY
Procedure :
[MAIN BOARD](SIDE B)
1. Connect the freguency counter to TP47 and TP8(GND).
2. Adjust RV401 so that the freguency at TP47 becomes 220 Hz.
2. Adjust RV401 so that the freguency at TP47 becomes 220 Hz.
Standard value : 117 to 223 Hz
Adjustment Location : Main board (See page 7)
SECTION 3
ADJUSTMENTS
3-1. MECHANICAL ADJUSTMENTS
PRECAUTION
1. Clean the following parts with a denatured alcohol-moistened
swab :
record/playback/erase head
pinch roller
rubber belts
rubber belts
capstan
2. Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head demagnetizer close to the erase
head.)
head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
6. Power supply voltage : 3V DC.
Torque Measurement
Torque Measurement
Mode
Torque Meter
Meter Reading
Forward
CQ-102C
1.97 to 3.92 mN • m
(20 to 40 g • cm)
(0.28 to 0.55 oz• inch)
Forward
CQ-102C
0.05 to 0.49 mN • m
(0.5 to 5.0 g • cm)
(0.007 to 0.07 oz• inch)
Fast Forward
more than 4.90 mN • m
and Rewind
CQ-201B
(50 g • cm)
(0.7 oz• inch)
Tape Tension Measurement
Mode
Tension Meter
Meter Reading
Forward
CQ-403A
more than 50g
( 1.77oz)
/Reverse
1
36
25
48
35
15
40
12
30
24
20
37
45
5
10
13
L401
IC401
R409
C420
C422
R417
R416
C416
R405
R402
R406
R407
RV401
C401
304
8
C410
C402
C403
C414
C415
R403
R404
R401
C412
C413
C407
TP46
TP82
TP47
TP51
TP63
+
–
–
frequency counter
TP47
TP8(GND)
Note: Adjust before the tape speed adjustment
TCM-900DV
7
Tape Speed Adjustment
Procedure :
Procedure :
TP8(GND)
TP47
RV601
RV401
DPC (MANUAL) Adjustment
RV602
RV603
RV604
IC401
1
48
Tape Speed
Adjustment
Adjustment
[MAIN BOARD] (B side)
Adjustment Location : Main board (B side)
set
test tape
WS-48A
(3kHz, 0dB)
WS-48A
(3kHz, 0dB)
10k
Ω
EAR (earphone) jack (J102)
digital frequency
counter
Note: Adjust on both sides DIR switch (S701) “ b “ and “ B “.
1. Set DPC switch (S904) to OFF, PITCH CONTROL switches
(S910, 911) to the center and play the test tape WS-48A.
2. Set REC TIME switch (S903) to NORMAL (4.8cm/s) and turn
SPEED CONTROL knob (RV901) fully to FAST.
3. Adjust RV601 so that the reading on the frequency counter
becomes 6000Hz.
4. Turn SPEED CONTROL knob (RV901) to the center and adjust
RV602 so that the reading on the frequency counter becomes
3010Hz.
3010Hz.
5. Set REC TIME switch (S903) to DOUBLE (2.4cm/s) and turn
SPEED CONTROL knob (RV901) fully to the center.
6. Adjust RV603 so that the reading on the frequency counter
becomes 1505Hz.
7. Turn SPEED CONTROL knob (RV901) fully to SLOW.
8. Adjust RV604 so that the reading on the frequency counter
8. Adjust RV604 so that the reading on the frequency counter
becomes 1050Hz.
9. Turn SPEED CONTROL knob (RV901) fully to FAST and
confirm the reading on the frequency counter becomes approx.
3010Hz.
3010Hz.
10. Set REC TIME switch (S903) to NORMAL (4.8cm/s) and turn
SPEED CONTROL knob (RV901) fully to SLOW.
11. Confirm the reading on the frequency counter becomes approx.
1505Hz.
TCM-900DV
8
z
Waveforms
2
4
5
IC301 ql
IC401 ej
IC901 2
PB mode
VOLT/DIV : 1 V AC
TIME/DIV : 0.2
TIME/DIV : 0.2
µsec
PB (DPC AUTO) mode
VOLT/DIV : 1 V AC
TIME/DIV : 1
TIME/DIV : 1
µsec
REC/PB mode
VOLT/DIV : 1 V AC
TIME/DIV : 10
TIME/DIV : 10
µsec
– MAIN SECTION (1/3) –
– MAIN SECTION (3/3) –
– SW SECTION –
– MAIN SECTION (2/3) –
3.6 Vp-p
0.25
µsec
3.8 Vp-p
1.30
µsec
25
µsec
3.6 Vp-p
Note on Schematic Diagram: MAIN SECTION
• 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.
•
f
: internal component.
• C : panel designation.
Note:
Note:
The components identi-
Les composants identifiés
fied by mark 0 or dotted par une marque 0 sont cri-
line with mark 0 are cri- tiques pour la sécurité.
tical for safety.
line with mark 0 are cri- tiques pour la sécurité.
tical for safety.
Ne les remplacer que par
Replace only with part
une piéce portant le
number specified.
numéro spécifié.
•
: B+ Line.
• H : adjustment for repair.
• Power voltage is dc 3V and fed with regulated dc power
• Power voltage is dc 3V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground
under no-signal conditions.
no mark : PLAY (DPC OFF)
(
no mark : PLAY (DPC OFF)
(
)
: REC
<
>
: PLAY (DPC AUTO)
• 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.
• Signal path.
E
: PB
a
: REC
3.8 Vp-p
0.25
µsec
3
IC701 wh
REC/PB mode
VOLT/DIV : 1 V AC
TIME/DIV : 0.2
TIME/DIV : 0.2
µsec
SECTION 4
DIAGRAMS
1
T101
REC mode
VOLT/DIV : 5 V AC
TIME/DIV : 5
TIME/DIV : 5
µsec
30 Vp-p
20.0
µsec
9
9
TCM-900DV
4-1. BLOCK DIAGRAMS – MAIN SECTION (1/2) –
MIC901
S901
J101
RV401
T101
X401
Q111
Q101
RV601
RV602
RV603
RV604
M601
RV901
DPC
768kHz
MOTOR
FLAT MIC
MIC SENS
L
H
SPEED CONTROL
L
R
R
FWD
REV
RECORD/
FWD
REV
PB
REC
FWD
REV
FWD
REV
PB
REC
PB
REC
-
+
PRE +IN
PRE
AMP
RIPPLE
FILTER
FILTER
PRE OUT
PRE IN
RF OUT
RF IN
PB
REC
MIN
LPF20
LPF21
A IN
BUF OUT
BUF IN
A OUT
OSC1I
FIN
CP OUT
CP IN
CP REF
CP REF
XTLO
XTLI
RESETN
LPF1I
LPF1O
MOD0
MOD1
MOD2
MOD3
FXIN
OSC1O
OSC2I
OSC2O
SPEED CTL
PIC M
C1
PIC CTL
MOTOR CTL
PIC RST
OUT
VSP
IN+
S/S
COM
OSC
UOUT
VOUT
WOUT
VOUT
WOUT
L
HRPE901
HEAD
ERASE
PLAYBACK/
S102-2
S101-4
S102-1
S101-3
MIC
(PLUG IN POWER)
MIC
POWER
Q107
ATT
Q104
S101-2
BIAS
SWITCH
Q106
+1.8V
REG
S101-1
DIGITAL
PITCH CONTROL
D/A
A/D
LPF
LPF
DATA RAM
DSP
KEY SHIFT
CONTROL
TIMING
OSC
MICOM IF
MODE
REGISTOR
AUT
MODE
REGISTOR
COMP
Q405
Q403
Q404
SYSTEM
CONTROL
DETECT
SPEED
CURRENT
DETECT
DRIVE
PRE
OUTPUT
BIAS/
OSC
WAVEFORM
DETECT
SOFT
SWITCH
CONTROL
SERVO
+B
(BATT)
SPEED CONTROL
SPEED CONTROL
SPEED CONTROL
SPEED CONTROL
POWER
(+3.6V)
PRE AMP
REC
PIC
PIC
OSC
BIAS
Q105
+B
Q401
PB/REC
SWITCH
SWITCH
(PWR)
+B
(PWR)
SWITCH
Q112
GAIN
GAIN
MOTOR
BRAKE
BRAKE
SWITCH
INITIAL
Q603,608
Q601
MOTOR
BRAKE
BRAKE
Q602
Q109
Q607
Q606
Q604
Q402
TAPE
SPEED
TAPE
SPEED
TAPE
SPEED
TAPE
SPEED
9.6cm/s
4.8cm/s
2.4cm/s
1.6cm/s
POWER
(+3.6V)
+1.8V REG
COM
U
V
W
V
W
• Signal path.
E
: PB
a
: REC
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