2. Connect between test point TP (FOK) and GND by lead wire.
CD SECTION
3. Turned Power switch on.
NOTE :
4. Put disc (YEDS-18) in and turned Power switch on again and
1. CD Block basically constructed to operate without adjustment.
actuate the focus search. (actuate the focus search when disc table
Therefore, check each item in order given.
is moving in and out.)
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
5. Check the oscilloscope waveform (S-curve) is symmetrical be-
3. Use the oscilloscope with more than 10MW impedance.
tween A and B. And confirm peak to peak level within
4. Clean an object lens by an applicator with neutral detergent when
2.4 ? 0.7Vp-p.
the signal level is low than specified value with the following
S-curve waveform
checks.
symmetry
Focus Bias Adjustment
This adjustment is to be done when the optical block is replaced.
A
Adjustment procedure :within 2.4 ? 0.7Vp-p
oscilloscopeB
(DC range)
BD (CD) board6. After check, remove the lead wire connected in step 2.
Note :rTry to measure several times to make sure that the ratio
TP (RF)+
of A : B or B : A is more than 10 : 7.
TP (VC)�
rTake sweep time as long as possible and light up the bright
1. Connect oscilloscope to test point TP (VC) and TP (RF) on BDness to obtain best waveform.
(CD) board.
2. Connect TP ADJ (IC301 @Y pin) to ground with lead wire on MainAdjustment Location : BD (CD) board. (see page 13)
board.
3. Turned power switch ON. (Stop mode)RF Level Check
4. Put disc (YEDS-18) in and press the ^ button.oscilloscope
5. Press the ^ button (Tracking servo ON).
BD (CD) board
6. Adjust RV101 so that the oscilloscope waveform is as shown in
the figure below (eye pattern).TP (RF)+
A good eye pattern means that the diamond shape ( ) in the center�
TP (VC)
of the waveform can be clearly distinguished.
7. After adjustment,remove the lead wire connected in step 2.Procedure :
1. Connect oscilloscope to test point TP (VC) and TP (RF) on BD
r RF signal reference waveform (eye pattern)(CD) board.
2. Turned Power switch on.
VOLT/DIV : 0.2V
3. Put disc (YEDS-18) in and press the ^ button.
TIME/DIV : 500ns
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
Note :
1.3 ? 0.3Vp-pClear RF signal waveform means that the shape Oa� can be clearly
distinguished at the center of the waveform.
r RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.level : 1.3 ? 0.3Vp-p
Adjustment Location : BD (CD) board. (see page 13)
S-Curve Check
Adjustment Location : BD (CD) board. (see page 13)
oscilloscope
BD (CD) board
TP (FEO)+
TP (VC)�
Procedure :
1. Connect oscilloscope to test point TP (VC) and TP (FEO) on BD
(CD) board.
� 20 � |
ACEC
