SECTION 5
ELECTRICAL CHECKING
Note:E-F Balance (1 Track Jump) Check
1. CD Block is basically designed to operate without adjustment. There-
fore, check each item in order given.oscilloscope
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 M& impedance.BD board
4. Clean the object lens by an applicator with neutral detergent when the
TP (TE)+
signal level is low than specified value with the following checks.TP (VC)�
S-Curve Check
Procedure :
oscilloscope
1. Connect oscilloscope to TP (TE) and TP (VC) on BD board.
BD board2. Turned power switc[POWER]h ( button) on.
3. Load a disc (YEDS-18) and playback the number five track.
TP (FE)+
4. Press theH button. (Becomes the 1 track jump mode)TP (VC)�
5. Confirm that the level B and A (DC voltage) on the oscillo-
Procedure:scope waveform.
1. Connect oscilloscope to TP (FE) and TP (VC) on the BD board.
1 track jump waveform
2. Connect between TP (FE1) and TP (VC) with lead wire.center of
3. Connect between TP (AGCCON) and TP (GND) with lead
wire.waveform
4. Turned power switc[POWER]h ( button) on.B
5. Load a disc (YEDS-18) and actuate the focus search. (In con-
sequence of open and close the disc tray, actua0Vte the focusA (DC voltage)
search)
6. Cofirm that the oscilloscope waveform (S-curve) is symmetri-
cal between A and B. And confirm peak to peak level withinlevel = 1.3 ? 0.6 Vp-psymmetry
4 ? 1 Vp-p.
A
S-curve waveformSpecified lev el:� 100 = less than ? 22%
B
symmetry
6. After check, remove the lead wire connected in step 1.
A
within 4 ? 1 Vp-pRF PLL Free-run Frequency Check
BProcedure :
1. Connect frequency counter to TP (PLCK) with lead wire.
7. After check, remove the lead wire connected in step 2 and 3.
frequency counter
Note:Y Try to measure several times to make sure than the ratio of A : BBD board
or B : A is more than 10 : 7.
Y Take sweep time as long as possible and light up the brightness toTP (PLCK)+
obtain best waveform.�
RF Level Check
2. Turned power switc[POWER]h ( button) on.
oscilloscope3. Put the disc (YEDS-18) in to play the number five track.
BD boardConfirm that reading on frequency counter is 4.3218 MHz.
TP (RF)+
TP (VC)�
Procedure:
1. Connect oscilloscope to TP (RF) and TP (VC) on BD board.
2. Connect between TP (AGCCON) and TP (GND) with lead
wire.
3. Turned power switc[POWER]h ( button) on.
4. Load a disc (YEDS-18) and playback.
5. Confirm that the oscilloscope waveform is clear and check RF
signal level is correct or not.
6. After check, remove the lead wire connected in step 2.
Note:Clear RF signal waveform means that the shape OE� can be clearly
distinguished at the center of the waveform.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.45 ? 0.3 Vp-p
14 |
ACEC
