Read Sony CMT-ED1 / HCD-ED1 / HCD-ED1A Service Manual online
– 11 –
P
r
o
c
e
d
u
r
e
:
1. Connect oscilloscope to test point
TP (RF).
2. Turned P ower s witc h on.
3. Put disc (YEDS-18) in and playback.
4. Adjust R V101 so that the wa
3. Put disc (YEDS-18) in and playback.
4. Adjust R V101 so that the wa
vef orm is c lear .
(Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.)
5. After adjustment, check the RF signal level.
• RF signal
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
TIME/DIV: 500 nS
S Curve Check
Procedure :
1. Connect oscilloscope to test point
1. Connect oscilloscope to test point
TP (FEO).
2. Connect between test point
TP (FOK) and Gr ound b y lead wire .
3. Turn P ower s witc h on.
4. Put disc (YEDS-18) in and turned Power switch on again and
4. Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
table is moving in and out.)
5. Check the oscilloscope waveform (S-curve) is symmetrical be-
tween A and B. And confirm peak to peak le
vel within 2.4
±
0.7
Vp-p.
S-curve waveform
6. After c hec k, remo ve the lead wire connected in step 2.
Note:
• Try to measure se
veral times to make sure than the ratio of
A : B or B : A is more than 10 :
7.
• Take s weep time as long as possib
le and light up the bright-
ness to obtain best waveform.
RF Level Check
Procedure :
1. Connect oscilloscope to test point
1. Connect oscilloscope to test point
TP (RF) on BD boar
d.
2. Turned P ower s witc h on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal 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
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 lens cleaning liquid
when the signal le
vel is lo w than specified v
alue with the f ol-
lowing c hec ks.
5. Adjust the focus bias adjustment when optical block is replaced.
Focus Bias Adjustment
–
+
oscilloscope
BD board
TP (RF)
TP (VC)
TP (VC)
level : 1.3
±
0.3 Vp-p
–
+
oscilloscope
BD board
TP (FEO)
TP (VC)
TP (VC)
symmetry
A
B
within 2.4
±
0.7 Vp-p
–
+
oscilloscope
BD board
TP (RF)
TP (VC)
TP (VC)
level : 1.3
±
0.3 Vp-p
VOLT/DIV : 200 mV
TIME/DIV : 500 nS
TIME/DIV : 500 nS
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