Read Sony CDP-XB930 / CDP-XB930E Service Manual online
11
SECTION 5
ELECTRICAL BLOCK CHECKING
Note:
1.
CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
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
Ω
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.
when the signal level is low than specified value with the
following checks.
Procedure :
1.
1.
Connect oscilloscope to test point TP (FE) on SERVO board.
2.
Connect between test point TP (FEI) and TP (VC) by lead wire.
3.
Turn U (power) switch on.
4.
Put disc (YEDS-18) in and turn U (power) switch on again
and actuate the focus search. (actuate the focus search when
disc table is moving in and out.)
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.
between A and B. And confirm peak to peak level within 3±1
Vp-p.
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.
Procedure :
1.
1.
Connect oscilloscope to test point TP (RF) on SERVO board.
2.
Turn U (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
signal level is correct or not.
signal level is correct or not.
Note: A clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
Procedure :
1.
1.
Connect oscilloscope to test point TP (TE) on SERVO board.
2.
Turn U (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 oscilloscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%
Procedure :
1.
1.
Connect oscilloscope to test point TP (TE) on SERVO board.
2.
Connect the test point TP21 (ADJ) on MAIN board to the
ground with a lead wire.
ground with a lead wire.
3.
Turn the U (power) switch on to set the ADJ mode.
4.
Put disc (YEDS-18) in to play the number five track.
5.
Press the “4” button. (The tracking servo and the sledding servo
are turned OFF.)
are turned OFF.)
S-curve waveform
symmetry
A
B
within 3
±
1Vp-p
0V
level : 1.3
±
0.6 Vp-p
symmetry
A (DC voltage)
B
Center of the waveform
1track jump waveform
SERVO board
oscilloscope
TP(TE)
TP(VC)
TP(VC)
E-F Balance (1 Track Jump) Check
(Without remote commander)
(Without remote commander)
SERVO board
oscilloscope
TP(FE)
TP(VC)
TP(VC)
S Curve Check
SERVO board
oscilloscope
TP(RF)
TP(VC)
TP(VC)
RF Level Check
SERVO board
oscilloscope
TP(TE)
TP(VC)
TP(VC)
E-F Balance (Traverse) Check
(With remote commander)
(With remote commander)
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 1.45
±
0.25
Vp-p
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