Laptop won't turn on

Asus x551m

Won't turn on, no lights are active, screen is black all over. It suddenly went black while being used, i could have heard music as long as i didnt turn it off. Since then there is no respond, fan also won't start.

I have already tried another charger, putting the battery out, holding power button for 45 sec etc.

The only sign i can get is very quiet constant beep somewhere from the motherboard once the battery or charger are plugged in.

Any idea how to work it out guys? It's out of warranty unfortunatelly.