User blog comment:Narga99/3ds help/@comment-5043481-20130727221618

sounds like a battery problem to me, but I'm no expert with 3ds faults. Best take it to a repair place. You will probably have to pay for it being fixed, but it will almost certainly be cheaper than a new one.

Better contact nintendo. They will have some advice on what to do that is meaningful. You never know, they might replace it for you.