Can't figure out what's wrong with my Tab3 10.1

Hello guys.

First of all, i want to apologize for my bad English . I am portuguese, but I prefer to describe my problem in English in order to have better chances of help.

So, i got a Samsung Tab3 10.1 and suddenly it start to show some charging issues. Last week, i stopped being able to charge the tablet. I thought that was the battery dying, so i changed it for a new one. My problem still not solved with a new battery. When i connect the tab trough USB port, to my laptop, the computer beeps like something was connected, but still no image appears on the tab. So, my question is, what can i do to detect the real issue? Is it motherboard? Screen lcd? Charging flex?

I will be very grateful if someone can help me.

Hoping some feedback.

Thank you all!

Mário Eusébio