Cd Section - Aiwa CX-JT7 Service Manual

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 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
Oscilloscope
BD board
TP(FE)
TP(VC)
Procedure :
1. Connect an oscilloscope to TP (FE) and TP (VC).
2. 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
symmetry
A
B
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 an oscilloscope to TP (RF) and TP (VC).
2. Turn the power on.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check if RF
signal level is correct or not.
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SECTION 5
ELECTRICAL ADJUSTMENTS
Note: Clear RF signal waveform means that the shape " ◊ " can be clearly
distinguished at the center of the waveform.
RF signal waveform
Connecting Location: BD board
– BD Board (Conductor side) –
TP (VC)
within 3 ± 0.5Vp-p
TP (RF)
TP (FE)
IC721
manuals search engine
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.3 ± 0.3Vp-p
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CX-JT7