Mechanical Adjustment; Electrical Adjustment - Sony Walkman WM-GX670 Service Manual

SECTION 4

MECHANICAL ADJUSTMENT

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback/erase head
rubber belts
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.
• Torque Measurement
Mode Torque Meter
FWD CQ-102C
FWD
CQ-102C
Back Tension
REV CQ-102RC
REV
CQ-102RC
Back Tension
FF, REW CQ-201B
Adjustment Parts Location :
[MAIN BOARD] — SIDE A —
pinch roller
capstan
Meter Reading
15 to 25 g•cm
(0.21 to 0.34 oz•inch)
Less than 2.0g•cm
(Less than 0.028 oz•inch)
15 to 25 g•cm
(0.21 to 0.34 oz•inch)
Less than 2.0g•cm
(Less than 0.028 oz•inch)
More than 50 g•cm
(More than 0.69 oz•inch)
TP1
TP6
TP5
T1 : AM frequency coverage
— 11 —
SECTION 5

ELECTRICAL ADJUSTMENT

PRECAUTION
1. Specified voltage: 1.3 V (DC)
2. Switch and control position
MENU switch
aNR : OFF
AVLS : OFF
SOUND : OFF
HOLD : OFF
VOL : MAX
ISS : 1
Test Tape
Tape Signal
WS-48A 3 kHz, 0 dB
Tape Speed Adjustment
Procedure:
Test tape
WS-48A
(3kHz, 0dB)
Set
1. Enter the FWD playback mode.
2. Adjust RV601 so that the value of the frequency counter reading
becomes 3,000 Hz.
Specification value:
Frequency counter
2,955 Hz – 3,060 Hz
3. Check that the frequency deviation at the beginning and ending
of a tape is within 1.5 % (45 Hz).
[MAIN BOARD] — SIDE B —
L2 : FM frequency coverage
'?
L2
IC2
1 24
12
13
T2
T1
RV1
'?
T2 : AM IF adjustment
adjustment
Used for
Tape Speed Adjustment
Frequency counter
16
+
–
2 REMOTE jack (J701)
adjustment
RV601 : Tape speed
adjustment
'?
RV601
RV1 : FM VCO adjustment