18
CX-JDS22/JDS33
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
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.
S-curve Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (FEO) and TP (VC)
on the BD board.
2. Set the FUNCTION to “CD”.
3. While depressing the
N
(JDS22) (
nN
(JDS33)) button,
insert an AC plug.
4. Put the disc (YEDS-18) in and press the
x
button and actuate
the focus search. (actuate the focus search when disc table is
moving in and out)
5. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2
±
1
Vp-p.
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)(See page 19)
RFDC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point (RFDCO) 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.
Checking Location:
BD board (Side B)(See page 19)
RFAC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (RFACO) 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.
Checking Location:
BD board (Side B)(See page 19)
+
–
BD board
oscilloscope
TP (FEO)
TP (VC)
S-curve waveform
symmetry
A
B
within 2
±
1 Vp-p
+
–
BD board
oscilloscope
TP (RFDCO)
TP (VC)
RFDC signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
+
–
BD board
oscilloscope
TP (RFACO)
TP (VC)
RFAC signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
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