SECTION 5
ELECTRICAL BLOCK CHECKING
Note:S-curve waveform
1. CD Block is basically designed to operate without adjustment.symmetry
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 10MW impedance.
A
4. Clean the object lens by an applicator with neutral detergent when
Within 3.8 ? 1.1 Vp-p
the signal level is low than specified value with the following
B
checks.
S Curve Check (With general remote commander)
7. After check, remove the lead wire connected in step 2 and 3.
oscilloscopeNote :
BD boardY Try to measure several times to make sure than the ratio of A : B
or B : A is more than 10 : 7.
TP (FE)Y Take sweep time as long as possible and light up the
TP (VC)brightness to obtain best waveform.
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (FE) on BD board.
oscilloscope
2. Connect the test point JW003 (ADJ) on MAIN board to the
BD board
ground with a lead wire.
3. Turn ON the power.
TP (RF)
4. Put disc (YEDS-18) in prá (play) bess utton.TP (VC)
5. When the 11 button of the remote commander is pressed, the S
curve will be output continuously.
Procedure :
6. Check the oscilloscope waveform (S-curve) is symmetrical
+ 1.51. Connect oscilloscope to test point TP (RF) on BD board.
between A and B. And confirm peak to peak le� 1vel within 3
2. Turn ON the power.
Vp-p.
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check RF sig-
S-curve waveform
symmetrynal level is correct or not.
Note:
AA clear RF signal waveform means that the shape Oa� can be clearly
+ 1.5
Within 3 Vp-p� 1distinguished at the center of the waveform.
B
RF signal waveform
VOLT/DIV : 200mV
7. After check, remove the lead wire connected in step 2.
TIME/DIV : 500ns
Note :
Y Try to measure several times to make sure than the ratio of A : B
level : 1.2 ? 0.2 Vp-p
or B : A is more than 10 : 7.
Y Take sweep time as long as possible and light up the
brightness to obtain best waveform.
E-F Balance (1 Track Jump) Check
S Curve Check (Without general remote commander)
(Without general remote commander)
oscilloscope
oscilloscope
BD board
BD board
TP (FE)
TP (VC)TP (TE)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (FE) on BD boardProcedure :.
2. Connect between test point TP (FEI) and TP (VC) by lead wire1. Connect oscilloscpe to test point .TP (TE) on BD board.
3. Connect both ends of TP R151 of the BD board to the lead wire2. Turn ON the po.wer.
4. Turn ON the power.3. Put disc (YEDS-18) in to play the number five track.
5. Put disc (YEDS-18) in and actuate the focus search. (actuate the4. Press the P (Pause) button. (Becomes the 1 track jump mode)
focus search when disc table is moving in and out.)5. Check the level B of the oscilliscope's waveform and the A (DC
6. Check the oscilloscope waveform (S-curve) is symmetrvoltage) of the center of the icalTraverse waveform.
between A and B. And confirm peak to peak level within 3.8 ? 1Confirm the following :
Vp-p.A/B x 100 = less than ? 22%
� 10 � |
ACEC
