Read Sony CX-LMNV5 / XR-MNV5 Service Manual online
24
CX-LMNV5
RFDC signal waveform
Checking Location: BD board (Side B)(See page 25)
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10M
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.
1.
Connect an oscilloscope to test point TP6 (RFDC) and TP7 (VC)
on the BD board.
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.
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
TP6 (RFDC)
TP7 (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
RFAC Level Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP8 (RFAC) and TP7
(VC) on the BD board.
(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.
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)(See page 25)
+
–
–
BD board
TP8 (RFAC)
TP7 (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
S-curve Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP4 (FE) and TP7 (VC)
on the BD board.
on the BD board.
2.
While depressing the CD button, insert an AC plug.
3.
Put the disc (YEDS-18) in and press the button and
actuate the focus search. (actuate the focus search when disc
table is moving in and out)
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
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)(See page 25)
+
–
–
BD board
TP4 (FE)
TP7 (VC)
oscilloscope
A
B
symmetry
within 2
±
1 Vp-p
u
x
Click on the first or last page to see other CX-LMNV5 / XR-MNV5 service manuals if exist.