SECTION 5
ELECTRICAL ADJUSTMENTS
Precautions for AdjustmentFocus bias Check
1. Before beginning tracking balance adjustment, set the equip-Condition:
ment to service mode.Y Hold the set in horizontal state.
After the completion of adjustment, be sure to reset the ser-
vice mode.Check Procedure:
For more information, see OService Mode (service program)�oscilloscope
on page 9.(AC range)
2. Perform adjustments in the order given.MAIN board
3. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise2 k W
TP536 (RFO)+
indi- cated.TP537 (VC)�
4. Power supply voltage requirement.: DC 4.5 V
HOLD switch: OFF(See page 12)
VOLUME switch : Minimum
RESUME switch : OFF1. Set the equipment to service mode stop state. (See page 9.)
ESP switch: OFF2. Connect the oscilloscope to the test point TP536 (RFO) of the
AVLS switch: OFFMAIN board.
5. For adjustment, the remote comcommander is required.3. Move the optical pick-up to the center by pressing the (
(+) and = keys.
Before Beginning Adjustment4. Put the disc (YEDS-18).
Set the equipment to service mode (See page 9) and check the5. Press the ^ key.
following. If there is an error, repair the equipment.From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
Y Checking of the sled motor6. Press the PLAY MODE key. (Both tracking and sled are turned
1. Open the upper panel.ON.)
2. When continuously pressing ( (+) or = key on the7. Check the oscilloscope waveform is as shown below.
remote commander, and check that the optical picA good eye pattern means that the diamond shape (k-up canA) in the
move smoothly without sluggishness or abnormal noise in in-center of the waveform can be clearly distinguished.
nermost periphery ? outermost periphery ? innermost pe-
riphery. (At this time, the PLAY status is actiRF SIGNAL REFERENCE ve.)WAVEFORM (EYE PATTERN)
( (+) key on the remote commander:The optical pick-up
moves outwardly. VOLT/DIV : 200 mV (With the 10:1 probe in use)
= key on the remote commander: The optical pick-up TIME/DIV :moves 500 ns
in- wardly.
Y Checking of focus searching
1. Open the upper panel.
2. Press the ( (+) key on the remote commander. (FocusRF level
searching operation is activated continuously.)1.0 ? 0.2 V
3. Check the object lens of the optical pick-up for smooth up/
down motion without sluggishness or abnormal noise.
4. Press the p key.
Check that focus searching operation is deactivated. If not,
To watch the eye pattern, set the oscilloscope to AC range and
again press the p key slightly longer.increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
VCC Adjustment8. Stop revolving of the disc motor bp key pressing the y.
Adjustment Procedure:
9. After the completion of adjustment, reset service mode. (See
digital voltmeterpage 9.)
(DC range)
MAIN boardCheck Location: MAIN Board (See page 12.)
L401 (RV301 side)+
�
(See page 12)
1. Set the equipment to service mode stop state. (See page 9.)
2. Connect the digital voltmeter to L401 (RV301 side) of the
MAIN board.
3. Adjust RV401 on the MAIN board so that the reading on digi-
tal voltmeter goes 2.7 to 2.8 V.
4. After the completion of adjustment, reset service mode. (See
page 9.)
Adjustment Location: MAIN board (See page 12)
� 10 � |
ACEC
