Sony CDP-497 - SECTION 3 ELECTRICAL BLOCK CHECKING; Signal Testing and Waveform Analysis

CDP-497
SECTION
3
ELECTRICAL
BLOCK
CHECKING
Note:
1.
CD
Block
basically
constructed to
operate without
adjustment.Therefore,
check
each item
in order given,
2.
Use
YDES-18
disc
(3-702-101-01)
unless
otherwise
indicated.
3. Use
the
oscilloscope
with
more than lOMQ
inpedance,
4.
Clean
an
object lens
by an
applicator
with neutral
detergent
with
the
signal
level is
low than
specified
value with the
following
checks.
S
Curve
Check
BD
board
oscilloscope
{
TP (FE) o
TP (VC)
o-
RF Level
Check
BD board
{
oscilloscope
TP (RFC) o-
TP (VC)
o
Procedure:
1.
Connect
oscilloscope to test point TP (RFO)
on
BD board.
2. Ture
Power
switch on.
3. Put
disc
(YEDS-18) in and playback.
4.
Confirm that oscilloscope waveform is
clear and
check RF
signal
level is correct or not.
Note:
Clear RF signal
waveform
means
that
the shape
“
O
”
can
be
clearly
distinguished
at the center of the waveform.
Procedure:
1 .
Connect
oscilloscope to
test
point TP (FE) on BD
board.
2.
Connect
between
test
point TP (FEI) and
TP
(VC)
by lead
wire.
3.
Tured
Power
switch
on
and actuate the
focus serch. (actuate
the
focus
serch
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 3 ±
1
Vp-p.
,
VOLT/DIV:
200 mV
RF
signal waveform
TIME/DIV: 500 nS
S
curve
waveform
symmetry
5.
After
check,
remove the lead
wire
connected in step 2.
Note:
•
Try
to
measure several times to make
sure
that 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.
E-F
Balance Check
oscilloscope
BD
board
{
TP
(TE)
TP (VC)
o-
o
Procedure:
1.
Connect test point TP (ADJ) to ground and TP (TEI) to TP
(VC)
with lead wire.
2. Connect
oscilloscope
to
test point TP (TE)
on BD board.
3. Turn
Power
switch
on.
4. Put disc (YEDS-18) in and playback.
5. Confirm
that
the
oscilloscope
waveform is symmetrical on
the top and bottom in relation to
OV,
and
check
this level.
Treverse
oscilloscope
symmetry
-
6
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