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HCD-L7HD
CD SECTION
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
RF Level Check
BD board
TP(RFAC)
TP(DVC)
Procedure :
1. Connect oscilloscope to TP (RFAC).
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
Note: Clear RF signal waveform means that the shape "◊" can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance (1 Track jump) Check
BD board
TP (TE)
TP (DVC)
Procedure:
1.
Connect oscilloscope to TP (TE) and TP (DVC) board.
2.
Turned Power switch on.
3.
Load a disc (YEDS-18) and playback the number five track.
4.
Press the u (CD) button. (Becomes the 1track jump mode.)
5.
Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
1 track jump waveform
0V
level=1.3 ±0.6Vp-p
A
x 100=less than ±22%
Specification level:
B
30
SECTION 5
ELECTRICAL ADJUSTMENTS
oscilloscope
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.1 ± 0.3Vp-p
oscilloscope
+
–
Center of
waveform
B
A (DC voltage)
Symmetry
Adjustment Location :
[ BD BOARD ] – SIDE A –
IC101
TP(TE)
TP(DVC)
IC103
TP
(RFAC)
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