22
CD SECTION
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
Ω
impedance.
4. 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
Procedure :
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEI) and TP (VC) by lead wire.
3. Connect between TP (AGCCON) and TP (GND) by lead wire.
4. Turn Power switch on.
5. Load a disc (YEDS-18) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
6. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 4 ±1 Vp-p.
7. After check, remove the lead wire connected in step 2 and 3.
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.
RF Level Check
Procedure :
1. Connect oscilloscope to TP (RF).
2. Connect between TP (AGCCON) and TP (GND) by lead wire.
3. Turned Power switch on.
4. Load a disc (YEDS-18) and playback.
5. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
6. After check, remove the lead wire connected in step 2.
BD board
Oscilloscope
TP(FEO)
TP(VC)
Symmetry
S-curve waveform
Wthin 4
±
1Vp-p
A
B
TP(RF)
TP(VC)
BD board
Oscilloscope
Note :
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
E-F Balance (1 Track jump) Check
Procedure :
1. Connect oscilloscope to TP (TEO) and TP (VC).
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback the number five track.
4. Press the
X
button. (Becomes the 1 track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
6. After check, remove the lead wire connected in step 1.
Adjustment Location:
[BD BOARD] (Conductor Side)
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
Level : 1.45
±
0.3Vp-p
TP(TEO)
TP(VC)
BD board
Oscilloscope
Level=1.3
±
0.6 Vp-p Symmetry
A (DC voltage)
Center of
waveform
B
0 V
1 track jump waveform
Specified level: ––
×
100 = less than
±
22 %
B
A
TP
(XPCK)
TP
(TEO)
TP
(FEO)
TP
(FEI)
TP
(RF)
TP
(VC)
TP
(DGND)
TP
(AGCCON)
1
12
24
1
20
21
40
60
80
41
61
IC101
IC103
