have you got homebrew channel? and what firmware are you on?
if you havent got homebrew channel
install hackmii installer available below.
install it by going to wii/ datamanagment/ channels/sd and putting the sd card in.
if you already have homebrew channel download the correct ios and system menu from
NUS Downloader - WiiBrew
you can see which ios and system menu you need by checking this link below.
System Menu - WiiBrew
if you cant install wads then you need to install a cios first.
alternativaly there is a tutorial in the bricked wii section on restoring wii using cboot2.
i think i am correct in what i have said, if not please let me know.
I am not responsible for any of your actions taken when attempting to fix your wii.