Sony CX-JV1, Service Manual

Page: 18 / 98

18
CX-JV1
RFDC signal waveform
Connecting Location: BD board (Conductor Side)
(See page 19)
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
Connecting Location: BD board (Conductor Side)
(See page 19)
+
—
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 key, insert an AC plug.
3. Put the disc (YEDS-18) in and press the key 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.
Connecting Location: BD board (Conductor Side)
(See page 19)
+
—
BD board
TP (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 2 ± 1 Vp-p
N
x
SECTION 5
ELECTRICAL ADJUSTMENTS