why you don't try?
auto
https://www.amazon.de/Anker-2-Slot-Kartenleser-Kartenleseger%C3%A4t-unterst%C3%BCtzt/dp/B00LGNFIYS/ref=sr_1_1?ie=UTF8&qid=1465115343&sr=8-1&keywords=anker+sd+card+reader
Will this work for N3DSXL?
Because it has different item model number with (AK-)
I got this same problem and I use "Revoltec 80 in 1 Portable Cardreader". I think buying a new card reader is not worth or should I really try and lose some money?
By the way, I soldered ALT CLK, because it seems easier and rest I used this guide...