Legend Of Zelda Black Screen when trying to play ?

Hy My children have R4DS & both have Legend of Zelda Phantom Hourglass, my son cant play his anymore - the game starts to load then freezes with a black screen, can only get out my switching off - can any one help please? My daughters is ok, but she is not as far as him with the game. Thanks

https://www.romulation.org/forum/index.php?topic=1462.0

Thanks will give it a go