Mechanical Adjustments; Electrical Adjustments - Sony HCD-EP404 Service Manual

SECTION 4

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.
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
FF CQ-201B
REW CQ-201B
Tape Tension Measurement
Mode Torque Meter
FWD CQ-403A
pinch roller
rubber belts
idlers
Meter Reading
2.95 – 6.86 mN•m
(30 – 70 g•cm)
(0.42 – 0.97 oz•inch)
0.15 – 5.39 mN•m
(1.5 – 5.5 g•cm)
(0.021 – 0.076 oz•inch)
more than 5.89 mN•m
(more than 60 g•cm)
(more than 0.83 oz•inch)
more than 5.89 mN•m
(more than 60 g•cm)
(more than 0.83 oz•inch)
Meter Reading
more than 100 g
(more than 3.53 oz)
SECTION 5

ELECTRICAL ADJUSTMENTS

PRECAUTION
1. Setting
MEGA BASS switch : OFF
TAPE DECK SECTION
Test tape
Type Signal
P-4-A100 10 kHz, –10 dB
WS-48B 3 kHz, 0 dB
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: Playback
test tape
P-4-A100
(10 kHz, –10 dB)
set
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.
within
L-CH
1dB
peak
Output
level
R-CH
peak
Screw
position
L-CH
peak
3. Mode: Playback
test tape
P-4-A100
(10 kHz, –10 dB)
L-CH
set
R-CH
HEADPHONE board
PHONES jack (JK501)
screen pattern
45 °
in phase
good
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
HCD-EP404
0 dB=0.775 V
Used for
Head Azimuth Adjustment
Tape Speed Adjustment
level meter
32 Ω
+
–
HEADPHONE board
PHONES jack (JK501)
within
1dB
Screw
position
R-CH
peak
oscilloscope
32 Ω
V
H
+ +
– –
32 Ω
90 ° 135 ° 180 °
wrong
11