Read Sony HCD-V5500 / MHC-V5500 / MHC-V7700AV Service Manual online
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RF Level Check
Procedure :
1.
1.
Connect oscilloscope to test point TP (RF) on BD board.
2.
Turned Power switch on.
3.
Put disc (YEDS-18) in to play the number five track.
4.
Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
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
CD SECTION
Note :
1.
CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
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 10M
Ω
impedance.
4.
Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
when the signal level is low than specified value with the
following checks.
S Curve Check
Procedure :
1.
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.
Turned Power switch on.
4.
Put disc (YEDS-18) in and turned Power switch on again 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.)
5.
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 3 ± 1
Vp-p.
between A and B. And confirm peak to peak level within 3 ± 1
Vp-p.
S-curve waveform
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.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
BD board
Oscilloscope
TP (FE)
TP (VC)
TP (VC)
A
B
Within 3
±
1 Vp-p
Symmetry
BD board
Oscilloscope
TP (RF)
TP (VC)
TP (VC)
Level : 1.3 Vp-p
+0.25
–0.20
–0.20
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
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