I have another solution. My Wii would not read discs (and gave me a few error messages). I tried the Wii disc cleaning solution and making sure the games were clean, but neither worked. I also tried all of the other troubleshooting solutions, and none worked.

When I looked at the back of the Wii, I noticed a few vents and what looked kind of like a fan. Blowing on it, a bunch of dust came out. I blew on it a few more times until no more dust came out. And the next thing I knew, the Wii worked! Maybe it was clogged with dust? Regardless, this simple solution worked for me.