I have recently bout my 2ds from a stranger at the mall and it was fine and all buttons worked.My 2ds works perfectly fine but my R button stays responding when i do not touch it.
For example; I would turn my 3ds on and the Camera will show up on the upper screen and the R button will automatically darken as if i pressed it and i dont even touch it.
This can get so annoying when i play a game because most of the actions i cannot do because of the stuck button it think.
I need answers, if you help me i will allways remeber you when i play my 2ds 
PLEASE HELP ME!