Weird lines going down screen?

Theres Green/Black lines going all down the screen. In some games it's worse than others (Some it's totally not noticable).

It started when we had a power cut. The Wii would'nt turn on for a while, but after having left it off for a while, it started to work again. But now... theres lines!

whats going on? Thanks :)

What ever it is i certainly doesn't sound good, are you 100% positive this problem wasn't there before you have the powercut?

Double check all your connections, but it's possible your Wii got damaged by the power-cut.

Uh-oh, from people I've heard with similar symptoms it sounds like your Wii's graphics chip is fried. It'll need a trip to Nintendo.