— 14 —
Notes on Check
1.
Perform the traverse check in the CD test mode.
After check, be sure to exit the test mode.
2.
Perform check in the order given.
3.
Use the disc (YEDS-18, Parts No. 3-702-101-01) only when
so indicated.
Before Check
Put the set into test mode and perform the following checks.
Repair if there are any problems.
• Sled Motor Check
Press
+
,
=
keys 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.
(Cancellation of BTL mute)
+
: Optical pick-up moves to the outer circumference.
=
: Optical pick-up moves to the inner circumference.
•
Focus Search Check
1.
Press the CD
^
key. (Focus search operation is performed
continuously.)
2.
Look at the Optical pick-up objective lens and confirm that it
moves up and down smoothly, with no catching or abnormal
noises.
3.
Press
p
button.
Confirm that focus search operation stops. If it does not, press
p
button again longer.
How to Enter the Set into Test Mode
1.
Turn the AC CORD IN (Adaptor).
(LCD 501 indicator blinks the test mode pattern.)
2.
Short-circuit between the lands as shown on the control (1)
board.
How to Exit the Test Mode
Turn the POWER OFF.
[CONTROL (1) BOARD]
CD SECTION
E-F Balance Check
Adjustment Location : MAIN board (See page 23)
This check is to be done when the optical pick-up block is replaced.
Check Procedure:
1.
Connect the oscilloscope to test point TP (VC) and TP (TE) on
MAIN board.
2.
Put the set into test mode.
3.
Optical pick-up setting to the center by
+
or
=
button
pushing.
4.
Insert disk (YEDS-18) and press
^
button.
5.
Check that the oscilloscope traverse waveform is symmetrical,
as shown in the figure below.
6.
Release test mode after adjustment is completed.
[MAIN BOARD]
A
B
C
0V
VOLT/DIV : 0.1V
TIME/DIV : 1ms
A = B C = 500mV
±
100mV
Jumper wire
Test portion
Short : Test mode
Open : Normal mode
TP(FE)
TP(RF)
TP(TE)
TP(TE)
TP(VC)
TP(VC)
Osilloscope
(DC range)
+
–
