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– 21 –

1. Perform adjustment in test mode.

After adjustments, be sure to release test mode.

2. Perform adjustments in the order given.
3. Use the disc (YEDS-18. Part No. 3-702-101-01) only when so

indicated.

Put the set into test mode and perform the following checks.
Repair if there are any problems.

1. Press 

^ button, then press p button.

2. Press 

+, = buttons and confirm that the optical pick-up

moves smoothly from the innermost to outermost circumfer-
ence and back smoothly and with no catching or abnormal noises.

+ : Optical pick-up moves to the outer circumference
= : Optical pick-up moves to the inner circumference

1. Press 

^ button. (Focus serch operation is performed continu-

ously.)

2. Look at the optical pick-up objective lens and confirm that it

moves up and down smoothly, when no catching or abnormal
noises.

3. Press 

p button.

Confirm that focus search operation stops. If it does not , press
p button again longer.

1. Short-circuit following portion on the CONTROL board.
2. Turn the FUNCTION selector to CD position.

This adjustment is to be done when the optical pick-up block is
replaced.

+
–

CD MAIN board

TP (Tracking-Y)

TP (VC)

Oscilloscope

(DC range)

1. Put the set into test mode.
2. Connect oscilloscope between TP (TRACKING-Y) and TP

(VC).

3. Press 

+ and = buttons to move the optical pick-up to the

center.

4. Insert disc (YEDS-18) in and press 

^ button.

5. Adjust RV703 so that the oscilloscope traverse waveform is sym-

metrical, as shown in the figure below.

6. Release test mode after adjustment is completed.

A

B

0 V

A=B

VOLT/DIV: 0.2 V
TIME/DIV: 1ms

Adjustment value: 0.5 ± 0.2 Vp-p (A + B)

Adjustment Location: CD MAIN board (See page 24.)

1. Open the short-circuit to release test mode.

Short-circuit

– 22 –

This adjustment is to be done when the optical pick-up block is
replaced.

A frequency responce analyzer is necessary in order to perform this
adjustment exactly.
However, this gain has a margin, so even if it is slightly off, there is
no problem. Therefore, do not perform this adjustment.
Focus/tracking gain determines the pick-up follow-up (vertical and
horizontal) relative to mechanical noise and mechanical shock when
the 2-axis device operate.
However, as these reciprocate, the adjustment is at the point where
both are satisfied.
• When gain is raised, the noise when the 2-axis device operates

increases.

• When gain is lowered, mechanical shock and skipping occurs more

easily.

• When gain adjustment is off, the symptoms below appear.

• The time until music starts becomes

longer for 

p

→

^ on automatic

selection.

low

low or high

(

=, + buttons pressed.)

(Normally takes about 2 seconds.)

• Music does not start and disc

–

low

continues to rotate for 

p

→

^ or

automatic selection.
(

=, + buttons pressed.)

• Sound is interrupted during PLAY.

Or time counter display stops

–

low

progressing.

• More noise during 2-axis device

high

high

operation.

+
–

CD MAIN board

TP (RF)

TP (VC)

Oscilloscope

(DC range)

1. Put the set into test mode.
2. Connect oscilloscope between TP (RF) and TP (VC).
3. Press 

+ and = buttons to move the optical pick-up to the

center. (Move the optical pick-up to the music area on the disc
to enable easy visibility of the eye pattern.)

4. Insert disc (YEDS-18) in and press 

^ button.

5. Press the 

^ button. (Tracking Servo ON)

6. Adjust RV701 so that the oscilloscope waveform is as shown in

the figure below. (eye pattern)
A good eye pattern means that the diamond shape (≈) in the
center of the waveform can be clearly distinguished.

7. Release test mode after adjustment is completed.

VOLT/DIV : 0.2 V
TIME/DIV  : 500 nS

1.4 

±

 0.3 Vp-p

When observing the eye pattern, set the oscilloscope for AC
range and raise vertical sensitivity.

Adjustment Location: CD MAIN board (See page 24.)

– 23 –

high tracking gain
high fandamental wave
than for low gain

The following is a simple adjustment method.

Since exact adjustment cannot be performed, remember the
positions of the controls before performing the adjustment.
If the positions after the primary adjustment are only a little
different, return the controls to the original position.

7. Connect oscilloscope to TP (TRACKING-Y) and TP (VC).
8. Adjust RV704 so that the waveform is as shown in the figure

below. (tracking gain adjustment)

9. Release test mode after adjustment is completed.

+
–

TP (FOCUS-Y)

TP (TRACKING-Y)

TP (VC)

oscillosope
(DC range)

CD MAIN board

Procedure:
1. Keep the set horizontal.

If the set is not horizontal, this adjustment cannot be performed
due to the gravity against the 2-axis device.

2. Put the set into test mode.
3. Connect oscilloscope to TP (FOCUS-Y) and TP (VC).
4. Insert disc (YEDS-18) in and press 

^ button.

5. Press the 

^ button. (Tracking Servo ON)

6. Adjust RV702 so that the waveform is as shown in the figure

below. (Focus gain adjustment)

100 mV

0 V

• Inconnect Examples (DC level changes more than on adjusted

waveform)

low focus gain

0 V

250 mV

high focus gain

VOLT/DIV: 100 mV
TIME/DIV:2ms

VOLT/DIV: 100 mV
TIME/DIV:2ms

VOLT/DIV: 100 mV
TIME/DIV:2ms

100 mV
75 mV

0 V

VOLT/DIV: 1 V
TIME/DIV:2 ms

0 V

• Incorrect Examples (fundamental wave appears)

low tracking gain

VOLT/DIV: 1 V
TIME/DIV: 2ms

0 V

0 V

VOLT/DIV: 1 V
TIME/DIV: 2ms

– 24 –

RV702

FOCUS GAIN

RV704

TRACKING

GAIN

RV703

E-F BALANCE

RV701

FOCUS BIAS

CNP706

IC701

25

24

13

12

48

1

36

37

TP (VC)

TP (RF)

TP (TRACKING-Y)

TP (FOCUS-Y)