SECTION 2
ELECTRICAL ADJUSTMENTS
1.
Perform adjustments in the order given.
2.
Use YEDS-18 (Part No: 3-702-101-01) disc unless otherwise
indicated.
3.
Use the oscilloscope with more than 10 Mfl impedance.
RF PLL Frequency Adjustment
Procedure:
main board
TP (PCK)
O'
frequency counter
Focus Bias Adjustment
This adjustment should be made when replacing TOP (T-type
Optical Pick-up).
Procedure:
oscilloscope
(DC range)
main board
o
TP (RF)
-
1
k-
1.
Connect the frequency counter to test point TP (PCK).
2. Turn POWER switch on.
3. Adjust RV201 so that the reading on the frequency counter is
4.3218MHz ±30kHz
4.
Put disc (YEDS-18) in and press 0 button.
5.
Confirm that the reading on frequency counter is 4.3218MHz.
1.
Connect oscilloscope to test point TP (RF).
2.
Turn POWER switch on.
3. Put disc (YEDS-18) in and press > button.
4. Adjust RV104 for an optimum waveform eye pattern or so that
the peak is maximum. Optimum eye pattern means that shape
"O" can be clearly distinguished at the center of the wavefor-
E-F Balance Adjustment
This adjustment should be made when replacing TOP (T-type
Optical Pick-up).
Procedure:
oscilloscope
main board
TP (TEO) cym-
(DC range)
m.
RF signal waveform
Adjustment Location :main board
1.
Connect oscilloscope to test point TP (TEO).
2.
Connect test point TP (ADJ) and test point TP (TES) to
ground with lead wire.
3. Turn POWER switch on.
4.
Put disc (YEDS-18) in and press t> button.
5. Adjust RVlOl so that the traverse waveform is symmetrical
above and below.
6. After adjustment, remove the lead wire connected in step 5.
Note: Prominent that make
a
long of sweep time.
A = B (wlthln5%)
VOLT/DIV: IV
TIME/DIV: 1ms
-4