20
HCD-GX355/GX555/RG270/RG475/RG575
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
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.
•
Abbreviation
MX: Mexican model
S-CURVE CHECK
Procedure:
1. Connect an oscilloscope to TP (FE) and TP (VC) on the CD
board (except MX) or BD board (MX).
2. Press the
I
/
1
button to turn the power on.
3. Load the 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.
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.
Connecting Location: CD board (except MX)
BD board (MX)
RFAC LEVEL CHECK
Procedure:
1. Connect an oscilloscope to TP (RFACO) and TP (VC) on the
CD board (except MX) or BD board (MX).
2. Press the
I
/
1
button to turn the power on.
3. Load the disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check if RFAC
signal level is correct or not.
Note:
Clear RFAC signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
Connecting Location: CD board (except MX)
BD board (MX)
CD board (except MX)
BD board (MX)
oscilloscope
TP(FE)
TP(VC)
symmetry
S-curve waveform
within 3
±
0.5 Vp-p
A
B
TP(RFACO)
CD board (except MX)
BD board (MX)
oscilloscope
TP(VC)
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.3
±
0.3 Vp-p
– CD BOARD (Conductor Side) (except MX) –
– BD BOARD (Conductor Side) (MX) –
TP
(VC)
TP
(FE)
TP
(RFACO)
IC101
SECTION 5
ELECTRICAL ADJUSTMENTS
