Mechanical Adjustments; Electrical Adjustments - Sony HCD-EC55 Service Manual

QQ
3 7 63 1515 0

MECHANICAL ADJUSTMENTS

• Precaution
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
erase head
capstan
2. Demagnetize the record/playback head with a head
demagnetizer. (Do not bring the head magnetizer close to the
erase head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, appiy 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
FWD
back tension
FF
REW
TE • Tape Tension Measurement
L 13942296513
Mode
FWD
www
.
http://www.xiaoyu163.com
SECTION 5
pinch roller
rubber belts
idlers
Meter reading
2.0 – 8.0 mN • m
CQ-102AS (20 to 80 g • cm)
(0.28 – 1.12 oz • inch)
0.15 – 0.6 mN • m
CQ-102C (1.5 to 6 g • cm)
(0.021 – 0.083 oz • inch)
5 – 17.7 mN • m
CQ-201AS (50 to 177 g • cm)
(0.7 – 2.48 oz • inch)
5 – 17.7 mN • m
(50 to 177 g • cm)
CQ-201B
(0.7 – 2.48 oz • inch)
Tension Meter Meter Reading
more than 80 g
CQ-403A
(more than 2.82 oz)
x ao
y
i
http://www.xiaoyu163.com

ELECTRICAL ADJUSTMENTS

8
DECK SECTION
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
• Test Tape
Tape
P-4-A063
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:
1. Mode: Playback
test tape
P-4-A063
(6.3 kHz, −10 dB)
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
Q Q
3 6 7 1 3
L-CH
peak
Screw
position
3. Mode: Playback
test tape
P-4-A063
(6.3 kHz, −10 dB)
u163
.
4. After the adjustments, apply suitable locking compound to
the pats adjusted.
HCD-EC55/EC77/GX99
SECTION 6
2 9 9 4 2 8
(EXCEPT US, CND)
Signal
6.3 kHz, -10 dB Azimuth Adjustment
JACK board
PHONES jack
(J402)
set
1 5 0 5 8 2 9 9 4
within
1dB
Output
level
R-CH
peak
L-CH R-CH
peak
peak
JACK board
PHONES jack
(J402)
set
waveform of oscilloscope
m
in phase 45° 90° 135° 180°
co
good wrong
9 9
0 dB=0.775 V
Used for
level meter
+
–
2 8 9 9
within
1dB
Screw
position
oscilloscope
V H
25