Instructions
Unplug the Wii's power adapter cable from the wall.
Unplug the Wii's power adapter cord from the Wii itself. Nintendo recommends you also unplug any other wiring hooked to your Wii.
Leave the power cord unplugged at both ends for two minutes or longer.
Plug the power adapter cord into the back of the Wii, along with any other wires you removed earlier. Then plug the power adapter cord into the wall outlet. The machine should reset its tripped breaker itself.
Unplug the power cord from the wall and the unit again if it failed to come on normally after you plugged it in and tried to turn it on. This time, leave the adapter unplugged at both ends for more than 30 minutes.
Call Nintendo customer service (800-255-3700) if those procedures don't return your Wii to normal function.