Sterio Aiwa keep in security mode

[freeidea]

hello all,i have a Sterio Aiwa model NSX-SZ35,first time it start normaly and works for minute ,then it power off suddenly,and it wont work.last time ,it keep in security mode: no display no sound just a tic tac relay ,the only red led activated...
i opened the box i changed most capacitors.
the relay is not holding contact closed.no holding 12v..just a clic.
i solder all point .
i found 2 IC STK 490 040S and one transistor like BI370.in a metalic support.

can someone hel me to start my repair?
or how i can test the ic stk?
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i m studying in elecronic institut management