Adjustments; Mechanical Adjustments; Electrical Adjustments - Sony WM-GX410 Service Manual

3-1. MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured alcohol-moistened
swab :
record/playback/erase head
capstan
2. Demagnetize the record/playback/erase 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 parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
6. Power supply voltage : 3V DC.
Torque Measurement
Mode Torque Meter
Forward/Reverse CQ-102C
Forward
CQ-102C
Back Tension
Reverse
CQ-102RC
Back Tension
Fast Forward
CQ-201B
and Rewind

3-2. ELECTRICAL ADJUSTMENTS

Note:
1. Supplied voltage: 3 V (DC)
2. Switch and control position
VOLUME control
AVLS switch
REC TIME/PLAY MODE switch : NORMAL
ISS switch
TAPE DECK SECTION
Test Tape
Type Signal
WS-48A 3 kHz, 0 dB
Tape Speed Adjustment
Procedure:
test tape
WS-48A
(3kHz, 0dB)
set
SECTION 3

ADJUSTMENTS

pinch roller
rubber belts
Meter Reading
1.97 to 3.92 mN • m
(20 to 40 g • cm)
(0.28 to 0.55 oz• inch)
0.05 to 0.49 mN • m
(0.5 to 5.0 g • cm)
(0.007 to 0.07 oz• inch)
0.05 to 0.49 mN • m
(0.5 to 5.0 g • cm)
(0.007 to 0.07 oz• inch)
more than 4.90 mN • m
(50 g • cm)
(0.7 oz• inch)
: output level < > :AEP
FM -20dBm <-30dBm>
AM-30dBm <-40dBm>
: NORM
: 1
0 dB = 0.775 V
Used for
Tape Speed Adjustment
frequency counter
16Ω
i headphone jack (J401)
1. Set REC TIME switch (S706) to NORMAL (4.8cm/s).
2. Play back the center portion of tape in REVmode, adjust RV602
so that the reading on the frequency counter becomes 3,000 Hz.
3. Set REC TIME switch (S706) to DOUBLE (2.4cm/s).
4. Play back the center portion of tape in REVmode, adjust RV601
so that the reading on the frequency counter becomes 1,500 Hz.
Specifications:
NORMAL (4.8cm/s)
DOUBLE (2.4cm/s)
5. Confirm the frequency difference between the beginning and
the end of tape should be 1.5%.
NORMAL (4.8cm/s)
DOUBLE (2.4cm/s)
[MAIN BOARD] (SIDE B)
RV602
Adjustment Location: Main board (See page 9)
WM-GX410
: 2,985Hz - 3,015Hz
: 1,493Hz - 1,507Hz
: 45Hz
: 22.5Hz
RV602: Tape Speed Adjustment
(4.8cm/s)
RV601
RV601: Tape Speed Adjustment
(2.4cm/s)
7