24
CX-LMN5
RFDC signal waveform
Checking Location:
CD board (Conductor side)
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10M
Ω
impedance.
3. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
RFDC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (RFDC) and TP (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
TP (RFDC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
RFAC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (RFAC) and TP (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 (Side B)
+
–
BD board
TP (RFAC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
S-curve Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (FE) and TP (VC)
on the BD board.
2.
While depressing the (CD) button, insert an AC plug.
3.
Put the disc (YEDS-18) in and press the (CD) button
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 (Side B)
+
–
BD board
TP (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 2
±
1 Vp-p
u
x
Summary of Contents for AIWA SX-LMN5
Page 28: ...26 CX LMN5 MEMO ...
