Here is a little tool to check and repair your microSD from your DS Slot.It's a stripped down DSLinux that sole function is to automatically run dosfsck via a menu. So you need an expansion pack for memory in slot 2.It was tested first on a Supercard SD ( by sonny_jim the original packer ), on a R4 ( by pas ) and now also on a Cyclo EVO ( with a slot2 G6 lite as expansion pack ) by me but in theory it should work on anything that supports DLDI but without expansion pack it will crash.Thanks to FAST6191 for pointing to the relevant thread made by sonny_jimEnjoy and feel free to report problems or to give feedback if it works fine with a different expansion pack ;-)