Electrical Block Checking - Sony CDP-XE220 Service Manual

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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 10MΩ 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
BD board
TP (FEO)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (FEO) on BD board.
2. Connect between test point TP (FOK) and ground by lead wire.
3. Turn Power switch on.
4. Put disc (YEDS-18) in and turn Power switch on again and actu-
ate 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
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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
BD board
TP (RF)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turn Power switch on.
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
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SECTION 5

ELECTRICAL BLOCK CHECKING

oscilloscope
symmetry
A
Within 3 ± 1 Vp-p
B
oscilloscope
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Note:
A 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
(Without remote commander)
BD board
TP (TEO)
TP (VC)
Procedure :
1. Connect oscilloscpe to test point TP (TEO) on BD board.
2. Turn Power switch on.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the "P (Pause)" button. (Becomes the 1 track jump mode)
5. Check the level B of the oscilliscope's waveform and the A (DC
voltage) of the center of the Traverse waveform.
Confirm the following :
Q Q
A/B x 100 = less than ± 7%
3 6 7 1 3 1 5
1 track jump waveform
0V
level : 500 ± 100 mVp-p
E-F Balance Check (With remote commander)
BD board
TP (TEO)
TP (VC)
Procedure :
1. Connect the test point TP3 (ADJ) on MAIN board to the ground
with a lead wire on main board.
2. Connect oscilloscpe to test point TP (TEO) on BD board.
3. Turn the Power switch on to set the ADJ mode.
4. Put disc (YEDS-18) in to play the number five track.
5. Press the "3" button. (The tracking servo is turned OFF.)
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VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.3 ± 0.3 Vp-p
oscilloscope
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Center of the waveform
B
A (DC voltage)
symmetry
oscilloscope
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