Read Sony CMT-L1 / HCD-L1 Service Manual online
22
HCD-L1
SECTION 5
ELECTRICAL ADJUSTMENTS
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 10M
3. Use an oscilloscope with more than 10M
Ω 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.
following checks.
RF Level Check
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
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
Procedure:
1.
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 button. (Becomes the 1track jump mode.)
5.
Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
waveform.
1 track jump waveform
TP(RFAC)
TP(DVC)
TP(DVC)
BD board
oscilloscope
oscilloscope
BD board
TP (TE)
TP (DVC)
TP (DVC)
+
–
–
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 1.1
±
0.3Vp-p
A
B
0V
Center of
waveform
waveform
B
Symmetry
A (DC voltage)
level=1.3
±
0.6Vp-p
Adjustment Location :
[ BD (CD) BOARD ] — SIDE A —
IC103
TP
(RFAC)
TP(TE)
TP(DVC)
IC101
Specification level:
x
100=less than
±22%
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