my nintendo wii?

As you know i got a question about nintendo wii when i got it home we hooked it up & every thing was going just fine up to the point were i took & up graded it when i shouldn't have because it was for the internet.So i was woundering if you could give me some advice on how to fix my nintendo wii because at this point i can't get any kind of sound or picture.I can't even get my nintendo wii games to play either i can't get it to do anything at all so i woundering if you could tell me on how to fix & how to repair my nintendo wii so we can try to get it up & running again.

thanks