Read Sony CX-JV77 / JAX-V77 Service Manual online
21
CX-JV77
SECTION 5
ELECTRICAL ADJUSTMENTS
– BD49 BOARD (Conductor Side) –
TP4 (FE)
TP5 (RFAC)
TP (DVC)
TP6
(RFDC)
TP2 (TE)
Note:
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
TRAVERSE LEVEL CHECK
Procedure :
1. Connect an oscilloscope to TP70 (TE) and TP73 (DVC) on
the BD49 board.
2. Press the
I
/1
button to turn the power on.
3. Load the disc (LUV-P01) and playback the number nine track.
4. Press the
4. Press the
hH
button. (Becomes the 1 track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
Connecting Location:
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 LUV-P01 (Part No. 4-999-032-01) unless otherwise indicated.
3.
Use an oscilloscope with more than 10MW 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.
signal level is low than specified value with the following checks.
S-CURVE CHECK
Procedure :
1. Connect an oscilloscope to TP68 (FE) and TP73 (DVC) on
the BD49 board.
2. Press the
I
/1
button to turn the power on.
3. Load the disc (LUV-P01) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
search)
4. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 2
within 2
±
0.5 Vp-p.
Note:
•
Try to measure several times to make sure than the ratio
of A : B or B : A is more than 10 : 7.
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.
brightness to obtain best waveform.
RF LEVEL CHECK
Procedure :
1. Connect an oscilloscope CH1 to TP71 (RFDC), CH2 to TP72
(RFAC) and TP73 (DVC) on the BD49 board.
2. Press the
I
/1
button to turn the power on.
3. Load the disc (LUV-P01) and playback the number nine track.
4. Confirm that oscilloscope waveform is clear and check if RF
4. Confirm that oscilloscope waveform is clear and check if RF
signal level is correct or not.
level=1.2
±
0.55Vp-p
symmetry
A (DC voltage)
center of
waveform
waveform
B
DVC
1 track jump waveform
TP70 (TE)
TP73 (DVC)
BD49 board
+
–
–
oscilloscope
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 0.75
±
0.1Vp-p (RFDC)
1.05
±
0.3Vp-p (RFAC)
+
–
–
oscilloscope
TP71 (RFDC)
TP72 (RFAC)
BD49 board
TP73 (DVC)
symmetry
S-curve waveform
within 2
±
0.5Vp-p
A
B
+
–
–
oscilloscope
BD49 board
TP68 (FE)
TP73 (DVC)
CD SECTION
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