Sony CDP-70 - REFERENCE; Focus;Tracking Gain Adjustments

REFERENCE 1.
Focus/Tracking Gain Adjustments
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, 2,
there is no problem. Therefore, do not perform this adjust-
ment. 3.
Focus/tracking gain determines the pick-up follow up (verti- 4.
cal and horizontal) relative to mechanical noise and 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 oper-
ates increases.
@When gain is lowered, mechanical shock and skipping
occurs more easily.
@ When gain adjustment is off, the symptoms below appear.
Symptoms Tracking
eThe time until music
starts becomes longer for
@ — D or automatic
é l . ed
selection. (Kid, DD but- Onion. teh
tons pressed.) (Normally
takes about 1 seconds.)
@ Music does not start and
disc continues to rotate
for @ — DP or automatic
selection.
(Ki<J, DEI buttons pressed.)
@Disc table opens shortly
after aS be. low or high
Sound is interrupted dur-
ing PLAY or time counter
display stops progressing.
® More noise during 2-axis
device operation.
The following is a simple adjustment method.
—Primary Adjustment —
Note : Since exact adjustment cannot be performed, remem-
ber the positions of the controls before performing the
adjustment. If the position after the primary adjust-
ment are only a little different, return the controls to
the original position.
Procedure :
oscilloscope
(DC range)
main board C)
TP (FEO) soar emea +
|
TP (TEO) O=e- -7 | O-
Keep the set horizontal.
If the set is not horizontal, this adjustment
cannot be performed due to the gravity against the
2-axis device.
Insert disc (YEDS-18: Fifth Selection) and press > but-
ton.
Connect oscilloscope to main board TP (FEO).
Adjust RV103 so that the waveform is as shown in the
figure below. (focus gain adjustment)
Connect oscilloscope to main board TP (TEO).
Adjust RV104 so that the waveform is as shown in the
figure below. (tracking gain adjustment)
VOLT /DIV : 100mV
TIME /DIV : 2mS
100mV
ov
@ Incorrent Examples (DC level changes more than on adjust-
waveform)
low focus gain
VOLT/DIV: 100mV
TIME /DIV : 2mS
250mV
ov
high focus gain
VOLT/DIV: 100mV
TIME/DIV : 2mS
100mV
75mV
OV
ov
@ Incorrect Examples (fundamental wave appears)
low tracking gain
TIME /DIV
ov
high tracking gain
higher fundamental wave than for low gain)
ov
Adjustment Location : main board
VOLT /DIV:
TIME /DIV :
VOLT/DIV :
VOLT/DIV :
TIME /DIV :
Iv
2ms
lV
: 2ms
IV
2ms