Read Sony CMT-EH55DAB / HCD-EH55DAB Service Manual online
HCD-EH55DAB
10
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback
head pinch
roller
erase
head
rubber
belts
capstan
idlers
2. Demagnetize the record/playback head with a head demag-
netizer. (Do not bring the head magnetizer close to the erase
head.)
head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, appiy suitable locking compound to the
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
Meter reading
FWD
CQ-102AS
2.0 – 8.0 mN • m
(20 – 80 g • cm)
(0.28 – 1.12 oz • inch)
FWD
Back Tension
Back Tension
CQ-102C
0.15 – 0.6 mN • m
(1.5 – 6.0 g • cm)
(0.021 – 0.083 oz • inch)
FF
CQ-201AS
5.0 – 17.7 mN • m
(50 – 177 g • cm)
(0.7 – 2.48 oz • inch)
REW
CQ-201B
5.0 – 17.7 mN • m
(50 – 177 g • cm)
(0.7 – 2.48 oz • inch)
TAPE TENSION MEASUREMENT
Mode
Torque meter
Meter reading
FWD
CQ-403A
more than 80 g
(more than 2.82 oz)
SECTION 5
MECHANICAL ADJUSTMENTS
SECTION 6
ELECTRICAL ADJUSTMENTS
DECK SECTION 0 dB = 0.775 V
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
TEST TAPE
Tape
Signal
Used for
P-4-A063
6.3 kHz, –10 dB
Azimuth Adjustment
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:
1. Mode:
1. Mode:
Playback
set
MAIN board
PHONES jack
(J102)
PHONES jack
(J102)
+
–
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
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.
so that outputs match within 1dB of peak.
Screw
position
L-CH
peak
within
1 dB
Output
level
L-CH
peak
R-CH
peak
within
1 dB
Screw
position
R-CH
peak
3. Mode:
Playback
set
test tape
P-4-A063
(6.3 kHz, –10 dB)
oscilloscope
V
H
waveform of oscilloscope
in phase 45
°
90
° 135° 180°
good
wrong
MAIN board
PHONES jack
(J102)
PHONES jack
(J102)
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
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