Is Nintendo to blame?
I've used my Nintendo 3DS for well over 1,000 hours (according to my Activity Log) over the past 27 months, and my system has finally shown some signs of wear.
For the past two days the Off slider for the 3D mode hasn't been working properly. I've been needing to slide the 3D slider on and off approximately ten times just to turn the 3D mode off.
Considering I must have used my 3D slider tens of thousands of times over the past two years and three months, I've accepted that I abused the unit.
While I enjoy playing most games in 3D, I find that mode annoying when playing Mario Kart 7 (the 3D effect is too weak), and Pokemon X (the 3D mode causes slowdown). Assuming my 3D slider is permanently broken, I can either:
Put up with the broken slider.
Disable the 3D mode in Parental Controls.
Have my 3DS repaired for $85 (not including tax and shipping).
Buy a new 3DS or 3DS XL.