Help me! My computer died and I dont know why [renamed]

my computer just died yesterday. It was ok the day before
I check all thing. When i turn on the power switch
it works but my monitor keep saying “no input signal”
I check if something wrong with the graphic card
so i take it from my PC and put in in another PC and it works fine

Could it be the motherboard that was broken???

I need help fast!!
I got all my data there. I dont wanna lose it.

Thanks