None at all? That's unusual even though not impossible.
Mix-up of european and american AV electronics often cause problems due to difference in the PAL/SECAM encoding used in EU and the NTSC encoding used in North America.
Some TVs can actually handle both. Such are most of the last generation CRTs. Oddly, a 15+ years old TV (latest generation CRT) could work better than newer generation LCD and plasma TVs, but it's a fact that I've seen many times.
Newer and cheaper LCDs and plasmas often only support either PAL/SECAM or NTSC, but not both.
(there are, in all fairness, at least some good reasons for that although in my personal opinion it's still mostly money and revenue driven exclusion)
Some new TVs would show bad quality image from the unsupported system (black and white with distortion on the screen) and other ones - perhaps like yours - would simply cut it off completely unless it's fully supported.
Unless you're missing the obvious (e.g. bad video cable connection) I don't think there's a simple and affordable solution. There are system converters, but I do NOT recommend using those - the cheap Chinese ones for $20 to $40 do not work well and the expensive ones are not worth the money.
If I had this problem - and I did - I'd end up buying a new Wii for the same region of the world that the TV is designed for.
Hope this helps. If it does then please rate it.
www.coppelltvrepair.com