I had this problem too, My 3DS would not charge when the cable was plugged into the back port or even when it was in the cradle. You could try and identify the problem yourself by following tutorials on the internet and looking at other's experiences, or you could take it to an electronics store. The thing about getting your 3DS repaired, however, is that some stores will unfortunately not be able to do any repairs at all. For example, I went to a nearby Best Buy but due to the console's age they didn't have parts. Ultimately I ended up getting an external charger to charge one of the two batteries I had, and then swapped them out when needed. But be careful, it's a huge pain if you accidentally strip the screws on the back. Hope this helps!
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
0