Are you just putting the files on the MicroSD? You need to be able to RUN a firmware update to make it apply, which means you need to update it on a DS/3DS that hasn't blocked it yet.Today the page www.R4ISDHC.COM change their information about the new update 5.1.0.11 claiming that the latest 2013 R4cards suport this firmware. I downloaded the latest file again to verify that the information is tue but my card that is a R4isdhc White Dual Core doesnt work, also i try diferent sd cards and the card still dead. It was working before I updated my 3DS XL to the latest firmware.