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WF-CD77H/E
CP-CD77
3. Servo
Unit
Since the adjusting procedure differs from that described in "ADJUSTMENT PROCEDURES OF AUDIO PRODUCTS",
Service
Manual.
All the semivariable
resistors must be set in the mechanical
Test Stage
Test
Mode
O
Focus
offset
Tracking
offset
Test Mode 1 (Confirmation
After loading the disc, set to Test Mode 2 (focus servo ON)
Test Mode 3 (Spin Servo ON)
Tracking
error balance
Test Mode 4 (Tracking Servo ON)
Focus
balance
Focus gain
Tracking
gain
*I
AdJust to obtain vertically symmetric waveform (Fig. 20-1) with respect to the reference DC level. The reference level is 1/2 vcc
—20mV
(approx. 2.5 V).
*2
Input oscillation
frequency:
*3
Input oscillation
frequency:
Measuring
the DC level
Figure
Value/ Adjusting Method
Adjusting
Parts
VR702
O ± 30 mV
O ± 30 mV
VR707
of laser lighting)
VR701
Adjust
VR704
amplitude
than 0.54 Vp-p) and min. jitter.
Adjust
VR705
on CHI
Adjust to obtain the same waveform
VR703
on CHI
1.3 kHz, 300 mV rms
1.5 kHz, 300 mV rms
-4
Symmetrical
up and down
20
center position.
to
obtain
clear
and
max.
of
eye pattern
(more
to obtain
the same waveform
and
CH2.
*2
and CH2.
*3
VR704
-20-
refer
Instrument
Connection
Pin 1 and Pin 2 of CNP701
Pin 3 and Pin 4 of CNP701
Pin
/2Vcc) and pin 3 (Ground) of TPI
Pin 1 ofTP1 and pin 2 (ground) ofTP1
Pin 6 (CHI) and pin 7 (CH2) of TPI
and ground
Pin 4 (CHI) and pin 5 (CH2) of TPI
and ground
1
VR705
VR703
VR701
VR702
VR707
CNP701
1
1 C700
IC701
Figure
20—2
to
the
9
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