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Text excerpt from page 17 (click to view)
CD SECTION
Notes: 1. CD block basically constructed to operate without adjustment. Therefore, 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� 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.
RF signal waveform
VOLT/DIV: 200 mV TIME/DIV: 500 ns (with the 10: 1 probe in use) level: 1.3 +0.25 Vp-p �0.20
When observing the eye pattern, set the oscilloscope for AC range and raise vertical sensitivity. When a general remote commander is not used (1 Track Jump Check): Procedure: 1. Connect the oscilloscope to TP (TE) and TP (VC) on BD board. 2. Turned power switch on. 3. Put disc (YEDS-18) in and press the � button, and play the number five track. 4. Press the � button. (Becomes the 1 track jump mode) 5. Confirm that the level B of the oscilloscope's waveform and the A (DC voltage) of the center of the traverse waveform. Confirm the following:
CN101
+ �
Procedure: 1. Connect the oscilloscope to TP (FE) and TP (VC) on BD board. 2. Connect between test point TP (FOK) and GND by lead wire. 3. Turned power switch on. 4. Put disc (YEDS-18) in and turned power switch on again and actuate the focus search. (actuate the focus search when disc table is moving in and out.) 5. Confirm that the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 3.0 ± 1.0 Vp-p.
S-curve waveform
symmetry
A�B � 100 = ± 7 (%) 2 (A + B)
Center of the waveform B
1 track jump waveform
A
within 3.0 ± 1.0 Vp-p
B
A (DC voltage) 0V
6. After check, remove the lead wire connected in step 2.
symmetry
level: 1.3 ± 0.6 Vp-p
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.
Connection Location:
[BD Board] (Side A)
RF Level Check Connection:
oscilloscope (AC range)
CN102
BD board TP (RF) TP (VC)
+ �
IC101 TP (FOK) IC103
Procedure: 1. Connect the oscilloscope to TP (RF) and TP (VC) on BD board. 2. Turned power switch on. 3. Put disc (YEDS-18) in and press the � button. 4. Confirm that the oscilloscope waveform is clear and check RF signal level is correct or not.
Note: Clear RF signal waveform means that the shape ��� can be clearly distinguished at the center of the waveform.
