Haven't started it with any exploit (no idea how to even use them), but I remember messing with one or two settings in the select menu.
Holding (A) and (B) while powering on didn't do anything either.
I remember I updated Twilight menu and the nds bootstrap to make the Tony Hawk games work (sadly one one did). I also tried formatting the SD card and putting in the files of a backup I made before updating the menu and bootstrap, still gives me a black screen. I know the DSi didn't crash on the games I played and I also took good care of it, so I made sure it never fell or hit against other objects.
BTW, sorry for the late answer.