Sony TCM-500DV, Service Manual

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TCM-500DV
7 7
SECTION 4
MECHANICAL ADJUSTMENTS
Tape Tension Measurement
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback/erase head pinch roller
capstan rubber belt
2. Demagnetize the record/playback/erase head with a head demag
netizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the rated power supply
voltage (3 V) unless otherwise noted.
Mode Torque Meter Meter Reading
1.97 – 3.92mN•m
FWD (20 – 40 g•cm)
CQ-102C
(0.28 – 0.55 oz•inch)
FWD
Back Tension
0.05 – 0.49 mN•m
REV (0.5– 5 g•cm)
REV (0.007 – 0.069 oz•inch)
Back Tension
FF, REW CQ-201B
more than 4.91 mN•m
(more than 50 g•cm)
(more than 0.69 oz•inch)
Mode Tension Meter Meter Reading
FWD CQ-403A
more than 50 g
(more than 1.76 oz)
Torque Measurement
SECTION 5
ELECTRICAL ADJUSTMENTS
Tape Speed Adjustment
Mode: playback
Procedure:
1. Set [REC TIME] switch (S401) to NORMAL (4.8 cm/s) posi-
tion, and playback the tape (WS-48A) .
2. Adjust RV602 so that frequency counter reading becomes 3,010
Hz.
3. Set [REC TIME] switch (S401) to DOUBLE (2.4 cm/s) posi-
tion.
4.Playback the tape from the beginning for two minutes, then ad-
just RV601 so that frequency counter reading becomes 1,505 Hz.
Confirm that deflection of the frequency counter reading between
the beginning and the end of tape is within 2% (NORMAL: approx.
60 Hz, DOUBLE: approx. 30 Hz) .
Setting:
• Supplied voltage: 3 V (DC)
• Switch and control position
VOL contorl (RV101) : mechanical center
REC SPEED switch (S401) : normal (4.8cm/s)
PAUSE switch (S601)
: OFF
SPEED CONTROL (RV201) : center click
VOR switch (S402)
: OFF
0 dB=0.775 V
Type Signal Used for
WS-48A 3 kHz, 0 dB tape speed adjustment
frequency
counter
test tape
WS-48A
(3 kHz, 0 dB)
16
Ω
EAR jack (J102)
set
+
–
Test Tape
Regulation Level
input level Mic –60dBs
output level earphone 16
Ω
, –20dBs
Adjustment Location:
– MAIN BOARD (Conductor Side) –
IC601
10
11
RV602
RV601
Tape Speed Adjustment
Tape Speed Adjustment
(Normal Speed)
(Double Speed)
1
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