Sony hcd-sd1 Section Electrical Adjustments, CD Section, Focus Bias Adjustment, Curve Check

SECTION 6

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 10MΩ impedance.

4.Clean the object lens by an applicator with lens cleaning liquid when the signal level is low than specified value with the fol- lowing checks.

5.Adjust the focus bias adjustment when optical block is replaced.

Focus Bias Adjustment

Perform this adjustment when the optical pick-up has been replaced or repaired.

oscilloscope

BD (CD) board
TP (RF)	+
TP (VC)	–

Procedure:

1.Connect oscilloscope to test point TP (RF).

2.Turned Power switch on.

3.Put disc (YEDS-18) in and playback.

4.Adjust RV101 so that the waveform is clear.

(Clear RF signal waveform means that the shape “ ◊” can be clearly distinguished at the center of the waveform.)

5.After adjustment, check the RF signal level.

•RF signal VOLT/DIV: 200 mV TIME/DIV: 500 nS

level : 1.3 ± 0.3 Vp-p

S Curve Check

oscilloscope

BD (CD) board
TP (FEO)	+
TP (VC)	–

Procedure :

1.Connect oscilloscope to test point TP (FEO).

2.Connect between test point TP (FOK) and Ground 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 be- tween A and B. And confirm peak to peak level within 2.4 ± 0.7 Vp-p.

S-curve waveform

symmetry

A

within 2.4 ± 0.7 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 bright- ness to obtain best waveform.

RF Level Check

oscilloscope

BD (CD) board
TP (RF)	+
TP (VC)	–

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 sig- nal level is correct or not.

Note: Clear RF signal waveform means that the shape “ ◊” can be

clearly distinguished at the center of the waveform.

•RF signal VOLT/DIV: 200 mV TIME/DIV: 500 nS

level : 1.3 ± 0.3 Vp-p

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