Sony CDP-XA50ES - SECTION 5 ELECTRICAL ADJUSTMENTS; S-Curve and E-F Balance Check; RF Level and PLL Frequency Checks

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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 MΩ 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.
Procedure:
1. Connect the oscilloscope to TP (FE) and TP (VC) on SERVO
board.
2. Connect the TP (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 TP (RF) and TP (VC) on SERVO
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
A
B
symmetry
within 3.0 ± 1.0 Vp-p
S-Curve Check
Connection:
+
–
SERVO board
TP (FE)
TP (VC)
oscilloscope
+
–
SERVO board
TP (RF)
TP (VC)
oscilloscope
(AC range)
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.
E-F Balance (Traverse) Check
Connection:
Procedure:
1. Connect the TP1 (ADJ) to ground and TP (TEI: IC101 pin @¶)
to TP (VC) with lead wire.
2. Connect the oscilloscope to TP (TE) and TP (VC) on SERVO
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 0 Vdc, and check this level.
6. After check, remove the lead wire connected in step 1.
RF PLL Free-run Frequency Check
Connection:
Traverse waveform
A
B
+
–
SERVO board
TP (TE)
TP (VC)
oscilloscope
(DC range)
level: 200 ± 100 mVp-p
+
–
TP (PLK)
SERVO board
frequency counter
Procedure:
1. Connect the frquency counter to TP (PLK).
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.