Sony PMC-D305, Service Manual

Page: 30 / 75

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E-F Balance Adjustment
This adjustment is to be done when the optical pick-up is replaced.
Procedure:
1. Connect the oscilloscope to TP (TRACKING-Y) and TP (VC)
on the CD board.
2. Insert the disc (YEDS-18) in and close the lid for CD.
3. Put the set into test mode.
4. Press the
+
and
=
buttons to move the optical pick-up to
the center.
5. Press the
(
button.
From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
6. Adjust RV703 so that the oscilloscope traverse waveform is sym-
metrical, as shown in the figure below.
A
B
0 V
A
B
0 V
A=B
Note: Take long sweep time
for easy monitoring.
VOLT/DIV: 0.2 V (with the 10:1 probe in use.)
TIME/DIV: 1 ms
A=B
Adjustment value: 0.4 ± 0.2 Vp-p (A + B)
7. Release the test mode after adjustment is completed.
Adjustment Location: CD board (See page 33.)
+
–
CD board
TP (TRACKING-Y)
TP (VC)
Oscilloscope
(DC range)
TEST 1
Terminal
How to Release the Test Mode
1. Press the
[OPERATE]
button to put the set into the standby
status.
2. Finally, disconnect and connect the AC plug cord.
Before Begining Adjustment
Put the set into test mode and perform the following checks.
Repair if there are any problems.
• Sled Motor Check
Press the
+
,
=
buttons and confirm that the optical pick-up
moves smoothly from the innermost to outermost circumference
and back smoothly and with no catching or abnormal noises.
+
: Optical pick-up moves to the outer circumference
=
: Optical pick-up moves to the inner circumference
• Focus Search Check
1. Press the
(
button. (Focus search operation is performed con-
tinuously.)
2. Look at the optical pick-up objective lens and confirm that it
moves up and down smoothly, when no catching or abnormal
noises.
3. Press the
p
button.
Confirm that focus search operation stops. If it does not , press
the
p
button again longer.
Note: When the malfunction is occurred by mis-passing other keys, turn
off the power and check again from making the test mode.
Notes on Adjustment
1. Perform adjustment in test mode.
After adjustments, be sure to release test mode.
2. Perform adjustments in the order given.
3. Use the disc (YEDS-18. Part No. 3-702-101-01) only when so
indicated.
How to Put the Set into Test Mode
1. Disconnect an AC plug cord.
2. Turn on the power while shorting the test point (TEST1). (Con-
nect the AC plug cord)
3. Opening the shorted test point puts the set into Test Mode.
[SW (A) BOARD] (Conductor Side)
CD SECTION
Ver 1.2 1999. 11