so how did you solve it?
i had about 5 black screens so far, trying ridge racer, mario and luigi dream team. Sometimes the game runned fine, sometimes it gave black screen.
Some black screens i got were just after clicking on "DS profile"
Some black screens i got were just after the 3ds game was launched.
I was using a MICROSD card kingston class 4, i bought a sandisk Ultra class 10 micro sd card and havent seen a black screen yet, but i bought it yesterday so i cant be so sure it will not hang up.
the strange part is that while on the 3ds menu, on mario and luigi EURO, the game icon appears, i hear luigi talk, but on the upper lcd screen there is no game graphic
perhaps its that im on firmware 4.4 and not 4.5, don´t know