I have 2 Wiis and I went to Nintendos Online support. I had the same problems
you have. But mine made noise. Very Loud noise.
They gave me a Fed Ex shipping label for free to send it in along with my Brawl Disc. My warranty was up but they fixed it free (all they did was clean the lens) and they returned it free of charge with a new disc. No scratches at all on my old one.
You can buy the lens cleaner at Frys or Best Buy for 10.00. Its really easy to use. I used it on my 2nd Wii. What a difference it makes. Doesn't make sense to me how but it worked. lol The cleaner is different than a regular cleaner.