Electrical Block Checking - Sony CDP-XE200 Service Manual

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 objective lens using an applicator with neutral detergent
when the signal level is low than specified value with the following
checks.
S Curve Check
BD board
TP (FE)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (FE) on BD board.
2. Connect between test point TP (FEI) and TP (VC) by lead wire.
3. Turn Power switch on.
4. Put disc (YEDS-18) in and turn Power switch on again and actuate
the focus search. (Actuate the focus search when disc table is moving
in and out.)
5. Check if 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.
• Set sweep time as long as possible and set 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.
SECTION 3

ELECTRICAL BLOCK CHECKING

oscilloscope
symmetry
A
within 3±1 Vp-p
B
oscilloscope
– 7 –
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check if RF
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.
RF signal waveform
E-F Balance (1 Track Jump) Check
BD board
TP (TE)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (TE) 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 oscilloscope's waveform and the A (DC
voltage) of the following :
A/B×100 = less than ± 20%.
1 track jump waveform
level : 1.5±0.7Vp-p
RF PLL Free-run Frequency Check
Procedure :
1. Connect frequency counter to test point (PLCK) with lead wire.
MAIN board
TP (PLCK)
2. Turn Power switch on.
3. Confirm that reading on frequency counter is 4.3218MHz.
VOLT/DIV : 200mV
TIME/DIV : 500nS
+0.25
level : 1.2 Vp-p
–0.20
oscilloscope
(DC range)
Center of the waveform
B
A (DC voltage)
symmetry
frequency counter