CFD-121 - Sony Audio Service Manual (repair manual). Page 14

– 14 –

• The time until music starts becomes

longer for 

π m fl on automatic selection.

(

≠, ± buttons pressed.)

(Normally takes about 2 seconds.)

• Music does not start and disc continues

to ratate for 

π m fl or automatic

selection.
(

≠, ± buttons pressed.)

• Sound is interrupted during PLAY. Or

time counter display stops progressing.

• More noise during 2-axis device

operation.

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

1. Connect the oscilloscope between TP (RF) and TP (VC).
2. Insert disc (YEDS-18) and push the 

fl button.

3. Adjust RV701 so that the oscilloscope waveform is maximum as

shown in the figure below (eye pattern).

• RF signal reference waveform (eye pattern)

A frequency response 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 raised, the noise when the 2-axis device operates

increases.

• When gain is lowered, it is more susceptible to machanical shock

and skipping occurs more easily.

When gain adjustment is off, the symptoms below appear.

oscilloscope

(DC range)

CD board

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

Adjustment Location : See page 16.

low

low or high

low

low

high

TP (RF)(IC702 

!¢

)

TP (VC)(IC701 

$•

)

0V

1.1 ± 0.2 V

VOLT / DIV : 0.2 V
TIME / DIV : 500 nS

–

–

high