Question Laptop not working out of a blue

Sep 8, 2019
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Hello guys, I guess it is stupid question, but is it possible, that motherboard in notebook is dead out of a blue ?
When I press ON button, button starts to glow, but nothing else (fan, hdd, etc...), to turn it off I need to hold ON button very long time.
Except this, WHEN I plug in AC - button on other side of laptop starts to glow as charging, BUT when try to start - nothing happens again.
I tried to start laptop without HDD - nothing
without RAM - nothing
take out battery for a day to reset everything - nothing

HOW can I determine what is dead ?

thank everybody for pushing me in right direction.

Jan