Mechanical Adjustment; Electrical Adjustment - Sony WM-EX651 Service Manual

SECTION 4

MECHANICAL ADJUSTMENT

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head pinch roller
rubber belts capstan
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
• Torque Measurement
Mode Torque Meter Meter Reading
14.7 to 24.5 mN•m
FWD CQ-102D (15 to 25 g•cm)
(0.22 to 0.34 oz•inch)
0.294 to 1.96 mN•m
FWD
CQ-102D (0.3 to 2.0g•cm)
Back Tension
(0.007 to 0.020 oz•inch)
14.7 to 24.5 mN•m
REV CQ-102C (15 to 25 g•cm)
(0.22 to 0.34 oz•inch)
0.294 to 1.96 mN•m
REV
CQ-102C (0.3 to 2.0 g•cm)
Back Tension
(0.007 to 0.020 oz•inch)
More than 34.3 mN•m
FF, REW CQ-201B (More than 35 g•cm)
(More than 0.69 oz•inch)
WM-EX651
SECTION 5

ELECTRICAL ADJUSTMENT

PRECAUTION
1. Specified voltage: 1.3 V (DC)
2. Switch position
HOLD : OFF
Test Tape
Tape Signal Used for
WS-48A 3 kHz, 0 dB Tape Speed Adjustment
Tape Speed Adjustment
Procedure:
Test tape
WS-48A
(3kHz, 0dB)
Frequency counter
16 Ω
+
Set
–
i REMOTE jack (J301)
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
2,970 Hz – 3,030 Hz
3. Check that the frequency deviation at the beginning and ending
of a tape is within 1.5 % (45 Hz).
Adjustment Point:
[MAIN BOARD] — SIDE B —
3
RV601
MEMO
11 11
WM-EX651