Sony CFD-460 - Page 11

Focus/Tracking Gain Adjustment
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 adjust-
ment.
Focus/tracking gain determines the pick-up follow-up (ver-
tical and horizontal) relative to mechanical noise and me-
chanical 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, it is more susceptible to mechanical
shock and skipping occurs more easily.
@ When gain adjustment is off, the symptoms below appear.
Gain | .
Focus Tracking
Symptoms
eThe time until music starts
becomes longer for STOP >>
low or high
PLAY on automatic selection low
low
high
(Kd | PPI buttons pressed. (Nor-
mally takes about 2 seconds.)
eMusic docs not start and disc
continues to rotate for STOP 9
» PLAY or automatic selection
(Ke, PPI buttons pressed.)
eSound is interrupted during
PLAY. Or time counter display
stops progressing
@ More poise during 2-axis device
operation.
| CFD-460
The following is a simple adjustment method.
—Simple Adjustment—
Note : Since exact adjustmeunt cannot be performed,
remember the positions of the controls before perfor-
ming the adjustment. If the positions after the simple
adjustment are only a little different, return the con-
trols to the original position.
oscilloscope
Procedurd
:
(DC
range)
CD
main
board
C)
eel
] |
TP (FOK) O=e = ay
TP (VREF)
1. Keep the set horizontal.
If the set not horizontal, this adjustment cannot be
performed due to the gravity against the 2 axis device.
Insert disc (YEDS-18) and press ® PLAY button.
Connect oscilloscope to CD main board TP (FOK).
4, Adjustment RV705 so that the waveform is as shown in
the figure below. (focus gain adjustment)
VOLT/DIV ; 100mV
TIME /DIV : 2ms
100mV
OV
® Incorrent Examples (DC level changes more than on adjust-
ed waveform)
low focus gain
VOLT/DIV : 100mvV
TIME /DIV : 2ms
250mV
OV
high focus gain
VOLT/DIV : 100mV
TIME /DIV : 2ms
100mV
75mV
OV