Technics SL-PG420A - Page 23

| SL-PG420A
{Operation
Sequence
Just
After
Power
On)
(TOC
Read
Operation-PLAY
Operation)
—
‘Power
On
Open/Close
switch
{no
disc
loaded)
pressed.
@ Power supply failure:
* Voltage regulator (IC11,
Q11~16, Q891~893)
* IC protector (ICP11, 12)
@ Microprocessor failure:
°1C401
@ Microprocessor failure
e 10401
@ Operation key switch failure
@ Tray switch failure
Has the tray opened
and stopped?
FL display came on?
Yes
Load a disc and press
the Open/Close switch.
@ Microprocessor failure
° IC401
@ Operation key switch fallure
@ Tray switch failure
No
Has the tray closed
and stopped? -
Yes
@ Microprocessor failure:
* 10401
"| @ Loading motor driver failure:
* 1C402,motor
@ Tray switch failure
Tray closed?
@ Pickup failure:
e Laser diode
No| @ Control system failure:
¢ 1C6501, 06502
@ Microprocessor failure:
© iC401
-— Laser diode turn-on check method ~
Remove the disc then close the tray,
and the laser diode will come on for
approx. 5 sec.
Laser diode came on?
Yes
@ Radial contro! system
failure:
e!C6504, Radial motor
e 1C401
Does optical
pickup move toward
inner track? ,
@ Microprocessor failure:
¢1C401 ,
@ Control system failure:
© 1C6501
@ FO error amp. failure:
¢ 1C6501, 1C6504
@ Pickup failure:
¢ Focus coil
Does focus fens
make vertical
movements?
No
Yes
Stops after making focus pull-
in operation for approx. 5 sec. |
@ Microprocessor failure:
°1C401
@T.T. drive system failure:
© 1C301, 402, Q351,
Turntable motor
Spindle motor No
Started rotation?
@
Yes
@