13
CD SECTION
Notes:
1. CD block basically constructed to operate without adjustment. There-
fore, check each item in order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise indicated.
3. Use the oscilloscope with more than 10 M
Ω
impedance.
4. Clean an object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
S-Curve Confirmation
Connection:
Procedure:
1. Connect an oscilloscope to IC703 pin
!∞
and TP (VC) on the
CD board.
2. Connect between TP (FOK) and TP (GND) on the CD board
by lead wire.
3. Turn the power ON.
4. Press the
[EJECT ]
(CD) button to open the disc tray, and
put the disc (YEDS-18).
5. Press the
[EJECT ]
(CD) button to close the disc tray (Actu-
ate the focus search).
6. Confirm that the waveform on the oscilloscope is symmetrical
between A and B and that peak to peak level is within 3.0 ±
1.0 Vp-p.
S-curve waveform
7. After confirmation, disconnect the lead wire in step 2.
Note:
• Try to measure several times to make sure that 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.
RF Level Confirmation
Connection:
Procedure:
1. Connect an oscilloscope to IC703 pin
!§
and TP (VC) on the
CD board.
2. Turn the power ON.
3. Load the disc (YEDS-18), and press the
[ ]
button to play-
back the disc.
4. Confirm that the waveform on the oscilloscope is clear and
that the RF signal level is correct.
Note:
Clear RF signal waveform means that the shape “
≈
” can be clearly
distinguished at the center of the waveform.
+
–
CD board
IC703 pin
!∞
TP (VC)
oscilloscope
+
–
CD board
IC703 pin
!§
TP (VC)
oscilloscope
(AC range)
RF signal waveform
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.
Connecting Location:
– CD Board (Conductor Side) –
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(with the 10: 1 probe
in use)
level: 1.3 Vp-p
+0.25
–0.20
6
6
within 3.0 ± 1.0 Vp-p
A
B
symmetry
TP (GND)
TP (VC)
TP (FOK)
20
11
1
10
CN701
IC701
IC703
^
Summary of Contents for HCD-VP1
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