Read Sony TCM-900DV Service Manual 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
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