Mechanical Adjustments; Electrical Adjustments - Aiwa CX-J3000 Service Manual

SECTION 5

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demag-
netizer.
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
REV CQ-102RC
REV
CQ-102RC
back tension
FF/REW CQ-201B
FWD tension CQ-403A
REV tension CQ-403R
pinch rollers
Meter reading
3.06 N • m to 6.96 N • m
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
0.19 N • m to 0.58 N • m
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
3.06 N • m to 6.96 N • m
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
0.19 N • m to 0.58 N • m
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
6.96 N • m to 14.02 N • m
71 to 143 g • cm
(0.98 – 1.99 oz • inch)
9.80 N • m
100 g or more
(3.53 oz or more)
9.80 N • m
100 g or more
(3.53 oz or more)
SECTION 6

ELECTRICAL ADJUSTMENTS

0 dB=0.775 V
DECK SECTION
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjust.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in
this service manual. (As a general rule, playback circuit
adjustment should be completed before performing recording
circuit adjustment.)
6. The adjustments should be performed for both L-CH and R-
CH.
7. Switches and controls should be set as follows unless otherwise
specified.
• Test Tape
Tape Signal
P-4-A063 6.3 kHz, −10 dB
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
DECK A DECK B
Note: Perform this adjustments for both decks
Procedure:
1. Mode: Playback
test tape
MAIN board
P-4-A063
PHONES jack
(6.3 kHz, –10 dB)
(J202 or J203)
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
MAIN board
P-4-A063
PHONES jack
(6.3 kHz, –10 dB)
(J202 or J203)
set
waveform of oscilloscope
in phase 45 ° 90 ° 135 ° 180 °
good
CX-J3000/J3000M
Used for
Azimuth Adjustment
level meter
+
–
within
1dB
Screw
position
R-CH
peak
oscilloscope
V H
wrong
13