Hardware New 3DS - problems with charging and discharging

[xenohbutton]

Hello everyone,

Something weird happened to my black New 3DS. It wasn't being used for some time and now It doesn't charge. I assumed it is charger port problem, so I just replaced it and bought new (original) battery. But it seems it's not that simple. Console still doesn't charge. I left it with the new battery for a couple of days. When I finally got some time for it, yesterday the battery appeared to be discharged again (that new one).

So I used battery from my white New 3DS just to check if the console just works. It does. I charged new battery from black console using fully working white console. But I put battery from white console into the black one. After a few hours, here are the results:

Battery put in white console did fully charge. It's working, it's fine, it's good. Nothing to complain.
Battery put in black console was completely out of power.

Both consoles were turned off all this time.

Any ideas what could have happened? And how to fix it? Not only charging port doesn't work but also battery in the console discharges on it's own.

 

[lone_wolf323]

Is there a game cart you keep in the black 3ds console?

 

[xenohbutton]

Is there a game cart you keep in the black 3ds console?

Nope. It's completely empty, there's even no memory card in the console.