One supercard dstwo user email me this question today :
I bought supercard dstwo last year and was using it until I decided to update so I could play more games with it . I downloaded the latest firmware and EOS version to the correct places, then put the card back in my 3DS and tried it but it still doesn’t work. I get a black screen with white text telling me it doesn’t work. I only have a 3DS and its version is 8.1.0-19E. Any help?
Quick solution :
Make sure you get this supercard dstwo : Supercard DSTwo .
Just use the alternate update method , take the update file name it from “dstwoupdate.dat” to “dstwoupdateb.dat”(just as pic shows as below : ), stick it in the root of your micro sd card, then put sd card back into supercard dstwo . Boot up your 3ds with dstwo, boot it up just like normal procedure . You will get the error screen as you met before, but this time just leave it on the error screen for a good 5-8 mins as its updating the bootloader now .After the good 5-8 mins reboot 3ds and your dstwo will work again . This is a proven method that works everytime, no need for a lower version of DS Lite or other lower version DS based systems to update . Using lower version DS Lite to update supercard dstwo is a very very old method .
change the name of “dstwoupdate.dat” to “dstwoupdateb.dat”