6-2. ELECTRICAL ADJUSTMENTNote:A clear RF signal waveform means thaa� can bet the shape O
clearly distinguished at the center of the waveform.
Note:
1. CD Block is basically designed to operate without adjustment.RF signal waveform
Therefore, check each item in order given.VOLT/DIV : 200mV
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.TIME/DIV : 500ns
3. Use an oscilloscope with more than 10MW impedance.
4. Clean the object lens by an applicator with neutral detergent+0.25
level : 1.2 Vp-p�0.20
when the signal level is low than specified value with the
following checks.
S-Curve Check
Adjustment Location: BD board (See page 19)
Oscilloscope
BD boardE-F Balance Check
Oscilloscope
TP (FE1)
BD board
TP (VC)
TP (TE)
Procedure :
TP (VC)
1. Chuck the disc (YEDS-18) beforehand, and disconnect the
power cord from the outlet.
2. Connect oscilloscope to test point TP (FE1) on BD board.
Procedure :
3. Connect test point (ADJ) on MAIN board to ground with lead
1. Chuck the disc (YEDS-18) beforehand, and disconnect the
wire.
power cord from the outlet.
4. The ADJ mode is set when the power cord is inserted into the
2. Connect oscilloscpe to test point TP (TE) on BD board.
outlet and power is supplied.
3. Connect test point (ADJ) on MAIN board to ground with lead
5. The fifth track is played automatically.
wire.
6. Press the CHECK button.
4. The ADJ mode is set when the power cord is inserted into the
7. Check the oscilloscope waveform (S-curve) is symmetrical
outlet and power is supplied.
between A and B. And confirm peak to peak level within 3?1
5. The fifth track is played automatically.
Vp-p.
6. Press the GROUP 3 button. (The tracking servo and the
sledding servo are turned OFF.)
S-curve waveform
Symmetry7. Check the level B of the oscilliscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ? 22%
A
Within 3 ? 1 Vp-p
Traverse waveform
B
Center of the waveform
8. Pressing the 1/u button stops the output of the waveform (sB
curve).
9. After check, remove the lead wire connected in step 3.0VA (DC voltage)
Note :Y Try to measure several times to make sure than the ratio of
A : B or B : A is more than 10 : 7.
Level : 1.3 ? 0.6 Vp-p
Y Take sweep time as long as possible and light up the
brightness to obtain best waveform.
8. Press the GROUP 8 button. (The tracking servo and sledding
Adjustment Location: BD board (See page 19)servo are turned ON.) Confirm the C (DC voltage) is almost
equal to the A (DC voltage) is step 7.
RF Level Check
Traverse waveform
Oscilloscope
BD board
TP (RF)
C (DC
TP (VC)
0Vvoltage)
Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.Tracking servoTracking servo
Sledding servoSledding servo
2. Turn Power switch on.
OFF ON
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check RF9. Disconnect the lead wire of TP1 (ADJ) connected in step 2.
signal level is correct or not.
Adjustment Location: BD board (See page 19)
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ACEC
