So the power led is not showing red, green or the standby colour?
Check the mains plug fuse.
Check the power connection going into the back of the Wii.
The power supply might be broken, is it warm at all? If you can check the power brick is outputting the necessary voltage as stamped on the side of the transformer. I would use a multimeter in situations like this, don't forget to probe into the power connection that goes into the Wii and not the mains voltage side.
A process of elimination is involved here.
I've never heard of a Wii getting so totally bricked that it can't even show the red off colour.