SECTION 4 ELECTRICAL ADJUSTMENTS
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� 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
E-F Balance (1 Track jump) Check
Oscilloscope BD board TP(FEO) TP(VC)
Note : Clear RF signal waveform means that the shape � � � can be clearly distinguished at the center of the waveform.
RF signal waveform VOLT/DIV : 200mV TIME/DIV : 500ns
Level : 1.45 ± 0.3Vp-p
Oscilloscope BD board TP(TEO) TP(VC)
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 ?/1 button 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.
S-curve waveform Symmetry
Procedure : 1. Connect oscilloscope to TP (TEO) and TP (VC). 2. Turned ?/1 button on. 3. Load a disc (YEDS-18) and playback the number five track. 4. Press the 7 button. (Becomes the 1 track jump mode.) 5. Confirm that the level B and A (DC voltage) on the oscilloscope waveform.
1 track jump waveform Center of waveform B A (DC voltage) 0V
A B Wthin 4 ±1Vp-p
Level=1.3 ±0.6 Vp-p Symmetry
Specified level: A � 100 = less than ± 22 % B
6. After check, remove the lead wire connected in step 1.
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
Oscilloscope BD board TP(RF) TP(VC)
Adjustment Location: [BD BOARD] (Conductor Side)
TP (RF) TP (VC)
Procedure : 1. Connect oscilloscope to TP (RF). 2. Connect between TP (AGCCON) and TP (GND) by lead wire. 3. Turned ?/1 button 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.
TP (GND)
