Ok so I just got my friends Wii.. it has BootMii as boot2 at the moment. The BootMii is the outdated v0.9.
He was trying to update his SM to 4.0 using the safe updater. Updated IOS60, then to 4.0u. In the process, HBC was updated.
Now when I boot the Wii, I just get a black screen. I can...