Sony BMZ-K1 / CX-BK1 Service Manual ▷ View online
25
CX-BK1
SECTION 6
MECHANICAL ADJUSTMENTS
•
TAPE MECHANISM DECK SECTION
Note:
Tape deck is not loaded in US model.
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads
pinch rollers
erase head
rubber belts
capstan
idlers
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
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
2.94 – 7.84 mN • m
(30 to 79 g • cm)
(0.42 – 1.11 oz • inch)
0.15 – 0.6 mN • m
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
2.94 – 7.84 mN • m
(30 to 79 g • cm)
(0.42 – 1.11 oz • inch)
2.94 – 7.84 mN • m
(30 to 79 g • cm)
(0.42 – 1.11 oz • inch)
6.86 – 17.64 mN • m
(70 to 179 g • cm)
(0.98 – 2.49 oz • inch)
9.8 mN • m
(100 • cm or more)
(1.4 oz • inch or more)
9.8 mN • m
(100 • cm or more)
(1.4 oz • inch or more)
Mode
Torque meter
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
Meter reading
FWD
FWD
back tension
back tension
REV
REV
back tension
back tension
FF/REV
FWD tension
REV tension
SECTION 7
ELECTRICAL ADJUSTMENTS
Note:
Tape deck is not loaded in US model.
Precaution
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
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 ad-
justment should be completed before performing recording
circuit adjustment.)
justment 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 other-
wise specified.
• Test Tape
Tape
Signal
Used for
P-4-A100
10 kHz, – 10 dB
Azimuth Adjustment
WS-48B
3 kHz, 0 dB
Tape Speed Check
0 dB = 0.775 V
DECK SECTION
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
position
L-CH
peak
peak
within
1dB
1dB
Output
level
level
L-CH
peak
peak
R-CH
peak
peak
within
1dB
1dB
Screw
position
position
R-CH
peak
peak
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: Playback
1. Mode: Playback
set
SPEAKER board
SPEAKER terminal (JK502)
L-CH, R-CH
SPEAKER terminal (JK502)
L-CH, R-CH
+
–
–
level meter
test tape
P-4-A100
(10 kHz, – 10 dB)
P-4-A100
(10 kHz, – 10 dB)
26
CX-BK1
3. Mode: Playback
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Record/Playback/Erase Head
set
test tape
P-4-A100
(10 kHz, – 10 dB)
P-4-A100
(10 kHz, – 10 dB)
R-CH
oscilloscope
L-CH
R-CH
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
SPEAKER board
SPEAKER terminal (JK502)
L-CH
SPEAKER terminal (JK502)
L-CH
Record Bias Adjustment
Procedure:
1.
1.
Record mode
2.
Mode: Playback
i-Bass OFF
BASS 0
TREBLE 0
i-Bass OFF
BASS 0
TREBLE 0
3.
Confirm playback the signal recorded in step 1 become
adjustment level as follows.
adjustment level as follows.
4.
If these levels do not adjustment level, adjustment the SFR451
(L-CH) and SFR452 (R-CH) to repeat steps 1 and 4.
(L-CH) and SFR452 (R-CH) to repeat steps 1 and 4.
Adjustment level: Playback output of 315 Hz to playback out-
put
of 10 kHz: 0
of 10 kHz: 0
± 1.0 dB (0 ± 4.5mV).
Adjustment Location: DECK board (Page 27)
+
–
–
set
recorded
portion
portion
SPEAKER board SPEAKER terminal (JK502)
level meter
attenuator
set
MAIN board
AUX IN jack (JK602)
AUX IN jack (JK602)
1) 315 Hz
2) 10 kHz
2) 10 kHz
50 mV (–23.8 dB)
600
Ω
blank tape
CN-123
CN-123
AF OSC
Tape Speed Check
Mode: Playback
1. Insert the WS-48B into the deck.
2. Press the
2. Press the
B
button.
3. Confirm that the frequency counter reads 3,000
± 90 Hz.
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
+
–
–
set
test tape
WS-48B
(3 kHz, 0 dB)
WS-48B
(3 kHz, 0 dB)
SPEAKER board
SPEAKER terminal (JK502)
L-CH, R-CH
SPEAKER terminal (JK502)
L-CH, R-CH
frequency counter
adjustment screw
27
CX-BK1
– DECK Board (Component Side) (Except US model) –
SFR451
Record Bias
Adjustment
(L-CH)
SFR452
Record Bias
Adjustment
(R-CH)
– MAIN Board (Conductor Side) –
AUX IN jack (R-CH)
AUX IN jack (R-CH)
JK602
– SPEAKER Board (Conductor Side) –
SPEAKER terminal
(R-CH)
JK602
SPEAKER terminal
(L-CH)
28
CX-BK1
RFDC signal waveform
Checking Location: CD board (Conductor side)
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10M
2. Use an oscilloscope with more than 10M
Ω impedance.
3. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
RFDC Level Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (RFDC) and TP (VC)
on the BD board.
on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFDC
signal level is correct or not.
signal level is correct or not.
Note:
A clear RFDC signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
+
–
–
BD board
TP (RFDC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
RFAC Level Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (RFAC) and TP (VC)
on the BD board.
on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
signal level is correct or not.
Note:
A clear RFAC signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
RFAC signal waveform
Checking Location: BD board (Side B)
+
–
–
BD board
TP (RFAC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
S-curve Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (FE) and TP (VC)
on the BD board.
on the BD board.
2.
While depressing the button, insert an AC plug.
3.
Put the disc (YEDS-18) in and press the button and
actuate the focus search. (actuate the focus search when disc
table is moving in and out)
actuate the focus search. (actuate the focus search when disc
table is moving in and out)
4.
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2
between A and B. And confirm peak to peak level within 2
± 1
Vp-p.
S-curve waveform
Note:
• Try to measure several times to make sure than the ratio of A : B
or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Checking Location: BD board (Side B)
+
–
–
BD board
TP (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 2
±
1 Vp-p
B
x
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