SECTION 5
ELECTRICAL ADJUSTMENTS
Notes:RF signal waveform
1. CD block basically constructed to operate without adjustment. There-
fore, check each item in order given.
VOLT/DIV: 200 mV
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise indicated.
TIME/DIV: 500 ns
3. Use the oscilloscope with more than 10 MW impedance.
(with the 10 : 1 prove
4. Clean an object lens by an applicator with neutral detergent when thein use)
signal level is low than specified value with the following checks.
+ 0.25
level: 1.2 Vp-p� 0.20
S-Curve Check
Note: Operate with remote commander.
Connection:
oscilloscope
SERVO board
When observing the eye pattern, set the oscilloscope for AC range
TP (FE)+
TP (VC)�and raise vertical sensitivity.
Procedure:E-F Balance (Traverse) Check
1. Connect the oscilloscope to TP (FE) and TP (VC) on SER(Operate with remote commander)VO
board.Connection:
2. Connect the TP (ADJ) and GND with lead wire.oscilloscope
3. Turned power switc! button) on.h((DC range)
4. Put disc (YEDS-18) in and press the N button. Press the qaSERVO board
button on remote commander. (actuate the focus search)
5. Confirm that the oscilloscope waveform (S-curve) is symmetri-TP (TE)+
TP (VC)�
cal between A and B. And confirm peak to peak level within
3.0 ? 1.0 Vp-p.
Procedure:
S-curve waveform1. Connect the TP (ADJ) to ground with lead wire.
2. Connect the oscilloscope to TP (TE) and TP (VC) on SERVO
symmetry
board.
3. Turned power switc! bh (utton) on.
A4. Put disc (YEDS-18) in and press the N button.
within 3.0 ? 1.0 Vp-p5. Press the 3 button on remote commander. (Tracking servo
on)
B
6. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 Vdc, and check this level.
6. After check, remove the lead wire connected in step 2.Traverse waveform
Note:Y Try to measure several times to make sure that the ratio of A : B
or B : A is more than 10 : 7.
Y Take sweep time as long as possible and light up the brightnessA
to obtain best waveform.
B
RF Level Check
Connection:
+ 1.5
oscilloscope
level: 1.5 Vp-p� 0.5
(AC range)
SERVO board7. After check, remove the lead wire connected in step 1.
TP (RFO)+
TP (VC)�E-F Balance (Traverse) Check
(No remote commander)
Connection:
Procedure:
oscilloscope
1. Connect the oscilloscope to TP (RFO) and TP (VC) on SERVO(DC range)
board.
SERVO board
2. Turned power switc! bh (utton) on.
3. Put disc (YEDS-18) in and press the N button.TP (TE)+
TP (VC)�
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 Oa� can be clearly
Procedure:
distinguished at the center of the waveform.
1. Connect the TP (TEI: IC101 pin wj) to TP (VC) with lead
wire.
2. Connect the oscilloscope to TP (TE) and TP (VC) on SERVO
board.
3. Turned power switc! bh (utton) on.
4. Put disc (YEDS-18) in and press the N button.
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ACEC
