– 18 –
1. Connect the oscilloscope to Pins
1
,
2
, and
3
of CN506 of the
MAIN board.
2. Check that no discs are loaded in the unit.
3. With the power ON, while pressing the GROUP 5 and
§
OPEN/CLOSE buttons, press the +100 button. The disc
table starts to rotate in the clockwise direction.
4. Loosen the fixing screw, move the mounting board (SENSOR),
and secure the mounting board (SENSOR) at the point the H
portion of the P.T waveform comes the center of the H portion
of the D.S waveform.
Disc Sensor Adjustment
Be sure to perform this adjustment after sensor adjustment in ME-
CHANICAL ADJUSTMENT.
Connection:
Waveform:
5. Rotate the DISC/CHARACTER knob in the counterclockwise
direction and the disc table starts to rotate in the same direction.
Check that the waveform at this time is the same as that in step
4. If larger by a considerable extent, rotate the DISC/CHAR-
ACTER knob in the clockwise direction and the disc table starts
to rotate in the same direction. Repeat from step 4.
6. Rotate RV501 of the MAIN board and adjust so that the H and L
portions of the D.S waveform become the same.
Fixing screw
Mounting board (SENSOR)
D.S: Pin
1
T.P: Pin
3
GND: Pin
2
oscilloscope
D.S
GND
T.P
MAIN board
CN506
D.S
P.T
D.S
P.T
Should be at the center
D.S
Adjust so that these widths
become the same.
Adjustment Location: MAIN board