SECTION 5
ADJUSTMENTS
CD SECTIONFocus Bias Check
Condition :
Precautions for AdjustmentY Hold the set in horizontal state.
1. Before beginning adjustment, set the equipment to service mode.
After the completion of adjustment, be sure to reset the serviceProcedure :
mode.
For more information, see OService Mode (service program)�[MAIN BOARD] (Side B)
on page 8.
oscilloscope
2. Perform adjustments in the order given.(AC range)
3. Use the disc (YEDS-18. Part No. 3-702-101-01) unless other-
wise indicated.IC501 @L pin
2k W(RFO)
4. Power supply voltage requirement : DC 4.5 V+
HOLD switch: OFF�
VOLUME: Minimum
IC501 #1 pin
BASS BOOST switch : NORM(VC)
AVLS switch: OFF
Before Beginning Adjustment
Set the equipment to service mode (See page 8) and check the
following.
23
If there in an error, repair the equipment.
IC501
30
Y Checking of the sled motor
1. Open the upper panel.
2. Press the + and = keys and check that the optical pick-up
can move smoothly without sluggishness or abnormal noise from
innermost periphery to outermost periphery then to innermost
periphery.
+ : The optical pick-up moves outwardly1. Set the equipment to service mode stop state (See page 8).
= : The optical pick-up moves inwardly2. Connect the oscilloscope between IC501 @L pin (RF0) and #1
pin (VC) on the MAIN board.
Y Checking of focus searching3. Move the optical pick-up by Pressing the + and = keys.
4. Put the disc (YEDS-18).
1. Open the upper panel.
2. Press the ^ key. (Focus searching operation is activated con-5. Press the ^ key.
tinuously).From focus searching, focus is turned ON while entering
(
3. Check the object lens of the optical pick-up for smooth up/downCLV drawing-in mode. Tracking and sled are turned OFF).
motion without sluggishness or abnormal noise.6. Press the PLAY MODE key. (Both tracking and sled are turned
ON).
4. Press the p key.
7. Check the oscilloscope waveform is as shown below.
Check that focus searching operation is deactivated. If not, again
press the p key slightly longer.A good eye pattern means that the diamond shape (a) in the
center of the waveform can be clearly distinguished.
RF level
0.85 � 1.15V
Y RF Signal Reference Waveform (eye pattern)
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
8. Stop removing of the motor by pressing the p key.
9. After the completion of adjustment, reset service mode.
(See page 8 )
N 9 N |
ACEC
