3ds not charging

So my charger port was broken and I ordered a charging dock for my 3ds, it still would not charge even if I forcibily connected the 3ds to the dock by hand as the 3ds wouldnt lock on to the dock anyways. Is this a battery issue? or do i need to fix the things that connect the 3Ds to the dock? I got the dock off amazon and dont think its fake. If it was a battery issue I could just replace it nice and easy but if its something else I have to take it to go get repaired so some help would be appreciated.