Cd Section - Aiwa CX-BK33 Service Manual

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CD SECTION

Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10MW 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.
S-CURVE CHECK
Connection:
BD board
TP (FE)
TP (VC)
Procedure:
1. Connect an oscilloscope to test point TP (FE) and TP (VC) on
the BD board.
2. While depressing the
3. Put the disc (YEDS-18) in and press the
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 ± 1
Vp-p.
S-curve waveform
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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)
RFDC LEVEL CHECK
Connection:
BD board
TP (RFDC)
TP (VC)
Procedure:
1. Connect an oscilloscope to test point TP (RFDC) and TP (VC)
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.
Note: A clear RFDC signal waveform means that the shape "◊" can be
clearly distinguished at the center of the waveform.
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oscilloscope
+
–
button, insert an AC plug.
N
button and actuate
x
symmetry
A
within 2 ± 1 Vp-p
B
oscilloscope
+
–
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8
RFDC signal waveform
Checking Location: CD board (Conductor side)
RFAC LEVEL CHECK
Connection:
BD board
TP (RFAC)
TP (VC)
Procedure:
1. Connect an oscilloscope to test point TP (RFAC) and TP (VC)
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.
Note: A clear RFAC signal waveform means that the shape "◊" can be
clearly distinguished at the center of the waveform.
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RFAC signal waveform
Checking Location: BD board (Side B)
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CX-BK33
9 4 2 8
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 0.6 ± 0.15 Vp-p
oscilloscope
+
–
0 5 8 2 9 9 4 2 8
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.0 ± 0.4 Vp-p
m
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