Mechanical Adjustment; Electrical Adjustment - Sony WM-GX221 Service Manual

WM-GX221
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 head with a head demagnet-
izer. (Do not bring a head demagnetizer close to the erase
head.)
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
FWD CQ-102C
FWD
CQ-102C
Back Tension
REV CQ-102RC
REV
CQ-102RC
Back Tension
FF, REW CQ-201B
8
pinch roller
capstan
Meter Reading
19.6 to 29.4 mN•m
(20 to 30 g•cm)
(0.28 to 0.42 oz•inch)
Less than 1.96 mN•m
(Less than 2.0g•cm)
(Less than 0.028 oz•inch)
19.6 to 29.4 mN•m
(20 to 30 g•cm)
(0.28 to 0.42 oz•inch)
Less than 1.96 mN•m
(Less than 2.0g•cm)
(Less than 0.028 oz•inch)
More than 39.2 mN•m
(More than 40 g•cm)
(More than 0.56 oz•inch)
SECTION 5

ELECTRICAL ADJUSTMENT

PRECAUTION
1. Specified voltage: 2.5 V (DC)
2. Switch and control position
VOL : MAX
SPEAKER : OFF
AVLS : NORM
SOUND BOOST : OFF
PB EQ : NORM
PAUSE : OFF
ISS : 1
FM SENSE : DX
(US, 5E)
FM MODE : FM ST
(EXCEPT US, 5E)
2X REC TIME : NORM
• Abbreviation
5E : E model with the indication of the country of origin.
TAPE SECTION
Tape Signal
WS-48A 3 kHz, 0 dB
Tape Speed Adjustment
Procedure:
Test tape
WS-48A
(3kHz, 0dB) 16 Ω (EXCEPT US MODEL)
32 Ω (US MODEL)
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
2,985 Hz – 3,015 Hz
3. Check that the frequency deviation at the beginning and ending
of a tape is within 1.5 % (45 Hz).
4. Set the 2x REC TIME switch to DOUBLE (2.4 cm/s).
5. Adjust RV602 so that the value of the frequency counter reading
becomes 1,500 Hz.
Adjustment Location : MAIN board (see page 9)
Used for
Tape Speed Adjustment
+
–
Frequency counter
2 jack (J301)