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 10 M� 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.
Procedure: 1. Connect oscilloscope to test point TP (TEO) on BD board. 2. Turned Power switch on. Press [FUNCTION] button to select CD. 3. Put disc (YEDS-18) in to play the number five track. 4. Press the p button, [ENTER/NEXT] button and ^ button simultaneously several times to fluorescent indicator tube display �SHUFFLE� is blink. (The sledding servo is turned OFF.) 5. Check the level B of the oscilloscope�s waveform and the A (DC voltage) of the center of the Traverse waveform. Confirm the following: A � 100 = less than ±7 (%) B
Traverse waveform Center of the waveform
Procedure: 1. Connect oscilloscope to test point TP (FEO). 2. Connect between test point TP (FOK) and GND by lead wire. 3. Turn 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. Check the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 3±1 Vp-p.
S-curve waveform
symmetry
B 0V A (DC voltage) symmetry level: 500 ± 100 mVp-p
A within 3 ± 1 Vp-p B
6. After check, remove the lead wire connected in step 2.
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.
6. Press the p button, [ENTER/NEXT] button and ^ button simultaneously several times to fluorescent indicator tube display �SHUFFLE� is OFF. (The sleding servo is turned ON.) Confirm the C (DC voltage) is almost equal to the A (DC voltage) is step 5.
Traverse waveform
RF Level Check
BD board TP (RF) TP (VC)
oscilloscope
+ �
0V
C (DC voltage) Sled servo OFF Sled servo ON
Procedure: 1. Connect oscilloscope to test point TP (RF) on BD board. 2. Turned Power switch on. 3. Put disc (YEDS-18) in and playback. 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.
