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17
HCD-GP6V
RFDC signal waveform
Checking Location: BD board (Conductor side)
RFAC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP6 (RFAC) and TP7
(VC) on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Note:
A clear RFAC signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
RFAC signal waveform
Checking Location: BD board (Conductor side)
CD SECTION
Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, 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.
S-curve Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP4 (FE) and TP7 (VC)
on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in and turned power switch on again
and actuate the focus search. (actuate the focus search when
disc table is moving in and out)
4.
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2 ± 1
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.
Checking Location: BD board (Conductor side)
RFDC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP6 (RFDC) and TP7
(VC) on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFDC
signal level is correct or not.
Note:
A clear RFDC signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
+
–
BD board
TP4 (FE)
TP7 (VC)
oscilloscope
A
B
symmetry
within 2
±
1 Vp-p
+
–
BD board
TP6 (RFDC)
TP7 (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 0.7
±
0.2 Vp-p
+
–
BD board
TP6 (RFAC)
TP7 (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p