Sony HCD-ZX9 Service Manual page 27

CD SECTION
Note:
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M 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
BD81A board
TP0102(FE1)
TP117(VC)
Procedure:
1. Connect oscilloscope to TP102 (FE1) and TP117 (VC).
2. Press the ?/1 button to turn the power ON.
3. Load a disc (YEDS-18) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
4. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 3 ±0.5 Vp-p.
S-curve waveform
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
BD81A board
TP124(RFACO)
TP117(VC)
Procedure:
1. Connect oscilloscope to TP124 (RFACO) and TP117 (VC).
2. Press the ?/1 button to turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Oscilloscope
symmetry
A
within 3 ± 0.5Vp-p
B
oscilloscope
Note: Clear RF signal waveform means that the shape "◊" can be
clearly distinguished at the center of the waveform.
Checking Location:
TP117
(VC)
TP0102
(FE1)
IC101
HCD-ZX9
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.3 ± 0.3Vp-p
TP124
(RFACO)
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