Sony CDP-C265 - SECTION 3. ELECTRICAL BLOCK CHECKING; S Curve Check; E-F Balance Check; RF Level Check

SECTION 3
ELECTRICAL BLOCK CHECKING
Note :
1. CD Block is basically designed to operate without
adjustment. Therefore, 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 1OMQ impedance.
4. Clean the object lens using an applicator with neutral
detergent when the signal level is low than specified value
with the following checks.
S
Curve
Check
oscilloscope
BD board
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. Turn Power switch on.
4. Put disc (YEDS-18) in and turn Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
5. Check if the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak
level within 3+1 Vp-p. ,
S-curve waveform symmetry
within 3 + 1 Vp-p
6. After check, remove the lead wire connected in step 2.
Note : « Try to measure several times to make sure than the
ratio of A: B or B: A is more than 10: 7.
«Set sweep time as long as possible and set the
brightness to obtain best waveform.
RF Level Check
oscilloscope
BD board
Procedure :
1. Connect oscilloscope to test point TP (RFO) on BD board.
2. Turn Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check if RF
signal level is correct or not.
Note :
A clear RF signal waveform means that the shape “(” can
be clearly distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV :500nS
WY
\
level:
1.2 O20 VP-P
Vy)
ER
()
’
+9
AANA
WW
E-F Balance Check oscilloscope
(DC range)
BD board
ce—
TP (TE) 2
TP (VC)
Procedure :
1. Connect test point TP (ADJ) on MAIN board to ground and
TP(TED to TP (VC) with a lead wire.
Connect oscilloscpe to test point TP (TE) on BD board.
Turn Power switch on.
Put disc (YEDS-18) in and playback.
Confirm that the oscilloscope waveform is symmetrical on
the top and bottom in relation to OV, and check this level.
aoe ee
Traverse waveform
Le
eH
OV dc
it i
symmetr
level: 2+1 Vp-p y y
6. Remove the lead wire connected in step 1.
RF PLL Free-run Frequency Check
Procedure :
1. Connect frequency counter to test point (PLCK) with lead
wire.
frequency counter
2. Turn Power switch on.
3. Confirm that reading on frequency counter is 4.3218MHz.