Mechanical Adjustments; Electrical Adjustments - Sony WM-EX900 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
playback head
capstan
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
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage (1.3 V) unless otherwise noted.
Torque Measurement
Mode Torque Meter
FWD
CQ-102C
FWD
back tension
REV
CQ-102RC
REV
back tension
FF, REW CQ-201B
pinch roller
rubber belt
Meter Reading
15 – 25 g • cm
(0.21 – 0.35 oz • inch)
less than 2 g • cm
(less than 0.03 oz • inch)
15 – 25 g • cm
(0.21 – 0.35 oz • inch)
less than 2 g • cm
(less than 0.03 oz • inch)
more than 50 g • cm
(more than 0.69 oz • inch)

ELECTRICAL ADJUSTMENTS

• Supplied voltage : 1.3 V
• Switches and control position
VOL switch : NORM
• Remote control position
HOLD switch : OFF
VOL control : MAX
SOUND mode : NORM
DOLBY mode : OFF
Test Tape
Type Signal
WS-48A 3 kHz, 0 dB
Tape Speed Adjustment
Procedure :
test tape
WS-48A
(3 kHz, 0 dB)
set
Playback WS-48A (tape center part) in the REV state and adjust
RV601 so that the digital frequency counter reading becomes
3,000 Hz.
Specification Value :
Digital frequency counter
2,985 to 3,015 Hz
Playback WS-48A (tape center part) in the FWD state and confirm
that the reading on digital frequency counter are between 2,985
to 3,015 Hz.
Adjustment Location :
– 9 –
SECTION 5
PRECAUTION
Used for
tape speed adjustment
digital
frequency counter
32 Ω
2
jack
RV601