Black screens could mean that you are missing some IOS that the game requires to run.
You can confirm which IOS your game needs using our list http://www.wiihacks.com/recommended-...s-use-run.html
You can also confirm which IOS you have by using DOP-IOS, a homebrew application.
Install IOS using Wad manager.
Note: Games usually need 38, 53, 55 or 56 to run.