Cd Section - Sony HCD-GRX9000 Service Manual

CD SECTION

Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, 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 10 MΩ 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.
S Curve Check
oscilloscope
BD board
TP (FEO)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (FEO).
2. Connect between test point TP (FOK) and GND by lead wire.
3. Turn 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. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 3±1
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 than 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
oscilloscope
BD board
TP (RF)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turned Power switch on.
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.
• FR signal
+
–
symmetry
A
within 3 ± 1 Vp-p
B
+
–
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.3 ± 0.3 Vp-p
E-F Balance (Traverse) check
(Without remote commander)
BD board
TP (TEO)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (TEO) on BD board.
2. Turned Power switch on. Press
CD.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the p button,
ton simultaneously several times to fluorescent indicator tube
display "SHUFFLE" is blink. (The sledding servo is turned
OFF.)
5. Check the level B of the oscilloscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following:
A
× 100 = less than ±7 (%)
B
Traverse waveform
0 V
level: 500 ± 100 mVp-p
6. Press the p button,
simultaneously several times to fluorescent indicator tube dis-
play "SHUFFLE" is OFF. (The sleding servo is turned ON.)
Confirm the C (DC voltage) is almost equal to the A (DC volt-
age) is step 5.
Traverse waveform
0 V
Sled servo OFF
– 18 –
oscilloscope
+
–
[FUNCTION]
button to select
[ENTER/NEXT]
button and ^ but-
Center of the waveform
B
symmetry
[ENTER/NEXT]
button and ^ button
C (DC
Sled servo ON
A (DC
voltage)
voltage)