CDP-XA20ES - Sony Audio Service Manual (repair manual). Page 13

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Procedure:
1. Connect the oscilloscope to TP2 (FE) and TP (VC) on BD
board.
2. Connect the TP3 (FEI: IC101 pin @ª) and TP (VC) with lead
wire.
3. Turned power switch on.
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.)
5. Confirm that the oscilloscope waveform (S-curve) is symmetri-
cal between A and B.  And confirm peak to peak level within
3.0 ± 1.0 Vp-p.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Note:
Try to measure several times to make sure that the ratio
of A : B or B : A is more than 10 : 7.
Take sweep time as long as possible and light up the
brightness to obtain best waveform.
RF Level Check
Connection:
Procedure:
1. Connect the oscilloscope to TP1 (RFO) and TP (VC) on BD
board.
2. Turned power switch on. (stop mode)
3. Put disc (YEDS-18) in and press the  
(  button.
4. Confirm that the 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
SECTION  5
ELECTRICAL  ADJUSTMENTS
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(with the 10: 1 probe
in use)
level: 1.2
Vp-p
+0.25
–0.20
+
BD board
TP2 (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 3.0 ± 1.0 Vp-p
– 13 –
Notes:
1. CD block basically constructed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Use the oscilloscope with more than 10 M
 impedance.
4. Clean an object lens by an applicator with neutral detergent
when the signal level is low than specified value with the fol-
lowing checks.
S-Curve Check
Connection:
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.
+
BD board
TP4 (TE)
TP (VC)
oscilloscope
(DC range)
level: 1.3 ± 0.7 Vp-p
+
TP13 (XPLCK)
BD board
frequency counter
A
Symmetry
B
Procedure:
1. Connect the TP18 (ADJ) to ground and TP5 (TEI: IC101 pin
@¶) to TP (VC)with lead wire.
2. Connect the oscilloscope to TP4 (TE) and TP (VC) on BD
board.
3. Turned power switch on.
4. Put disc (YEDS-18) in and press the  
(  button.
5. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to A Vdc, and check this level.
Traverse waveform
A/B 
×
 100 is ± 20 % or less.
6. After check, remove the lead wire connected in step 1.
RF PLL Free-run Frequency Check
Connection:
Procedure:
1. Connect the frequency counter to TP13 (XPLCK).
2. Turned power switch on.
3. Put disc (YEDS-18) in and press the  
(  button.
4. Confirm that the reading on frequency counter is 4.3218 MHz.
E-F Balance (Traverse) Check
Connection:
+
BD board
TP1 (RFO)
TP (VC)
oscilloscope
(AC range)
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