5. Check the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 2.4 ± 0.7 Vp-p.
S-curve waveform symmetry
Traverse waveform
A B
A within 2.4 ± 0.7 Vp-p B
level: 300 ± 100 mVp-p
specified level : � ������ � 100 = less than ± 7% A�B 2 (A+B) � A+B= 300 ± 100 mVp-p 6. Remove the lead wire connected in step 1. Focus/Tracking Gain Adjustment (RV102, RV103) This gain has a margin, so even if it is slightly off. There is no problem. Therefore, do not perform, this adjustment. Please note that it should be fixed to mechanical center position when you moved and do not know original position. Adjustment Location :
6. After check, remove the lead wire connected 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 Check
oscilloscope BD (CD) board TP (RF) TP (VC)
+ �
[BD (CD) BOARD] � Side B �
Procedure : 1. Connect oscilloscope to test point TP (VC) and TP (RF) on BD (CD) board. 2. Turned Power switch on. 3. Put disc (YEDS-18) in and press the · (CD) key. 4. Confirm that 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.
FOK
IC102 TEI FEI RV102
RF
IC101 FEO
RF signal waveform
VOLT/DIV: 200 mV TIME/DIV: 500 ns
Procedure : 1. Connect the TP (TEI) and TP (VC) with lead wire. 2. Connect oscilloscope to test point TP (VC) and TP (TEO) on BD (CD) board. 3. Turned Power switch on. 4. Put disc (YEDS-18) in and press the · (CD) key. 5. Confirm that the oscilloscope waveform is symmetrical on the top and bottom in relation to 0 Vdc, and check this level.
