User blog comment:Narga99/Goodbye Monster Hunter/@comment-11537809-20130728113924/@comment-11537809-20130729200706

Unfortunately I don't know since I haven't fixed mine. Apparently, you can also try gluing it on to the 3ds so it won't move. (see if there's anything loose)

Here are some links to replacement cables I found:

http://dx.com/p/repair-parts-replacement-genuine-nintendo-3ds-ribbon-cable-module-128545

http://www.eachmall.com/goods-29149.html